Prenatal yoga for stress reduction: results from the FELICITy-2 quasi-randomized controlled trial

Prenatal yoga for stress reduction: results from the FELICITy-2 quasi-randomized controlled trial | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Prenatal yoga for stress reduction: results from the FELICITy-2 quasi-randomized controlled trial Clara Becker, Marlene Julie Emilia Mayer, Martin Gerbert Frasch, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7366549/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 7 You are reading this latest preprint version Abstract Prolonged maternal stress during pregnancy can adversely affect offspring development. This study evaluated the efficacy of an integrative prenatal yoga program, combining Yoga Hatha and Yoga Nidra, in reducing maternal stress levels during pregnancy and childbirth. A prospective quasi-randomized controlled trial was conducted at the TUM University Hospital, Munich, from December 2022 to June 2024. Pregnant women between 12 + 0 and 20 + 0 weeks of gestation with elevated stress levels (Perceived Stress Scale-10 (PSS-10) ≥ 19) were eligible. 28 participants were included in the final analysis, with 14 assigned to a yoga intervention group and 14 to a control group receiving standard prenatal care. Stress was assessed via PSS-10, the Prenatal Distress Questionnaire (PDQ), and hair cortisol concentrations at baseline, during pregnancy, and postpartum. Both groups showed significant declines in PSS-10, PDQ, and cortisol over time. Improvements were slightly greater in the yoga group, but differences were not statistically significant. By integrating subjective and objective measures, this study provided insights into stress patterns during pregnancy. While the structured yoga program did not produce significant group differences, it may represent a meaningful and practical approach to prenatal stress reduction. Larger, more diverse studies are warranted. Registry: German Clinical Trials Register (DRKS), TRN: DRKS00037529, Registration date: 24 July 2025. Health sciences/Health care Health sciences/Medical research Yoga intervention Pregnancy Prenatal stress Perceived Stress Scale-10 Cortisol Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Pregnancy is accompanied by profound biopsychosocial adaptations, including weight gain and increased blood volume [ 1 , 2 ], hormonal fluctuations [ 3 ], lifestyle adjustments, and shifts in interpersonal relationships [ 4 ]. Such simultaneous transformations often precipitate stress: up to 78% of pregnant women report slighttomoderate stress, and around 6% experience high stress levels [5]. Stress can be defined as the perception of specific stimuli that cause physiological or psychological responses in an individual [ 6 ]. These triggers, referred to as “stressors”, may arise from environmental, psychological, or physiological origins. The “stress response” is understood as the adaptive reaction to stressors. According to the classic “fight or flight” model, the body mobilizes energy resources [ 7 , 8 ]. On a biochemical level, stress responses are primarily modulated by the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS). The hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to produce adrenocorticotropic hormone (ACTH). This leads to the adrenal secretion of cortisol as a delayed reaction. At the same time, the ANS, particularly the sympathetic branch, is activated, immediately releasing catecholamines like adrenaline and noradrenaline [ 9 – 11 ]. In addition to these classical pathways, reactive oxygen species, cytokines, and serotonin have also been identified as physiological mediators involved in the stress response [ 12 – 15 ]. In the context of prenatal stress, pregnancy-related concerns are added to the general stress. As pregnancy progresses, cortisol production increases substantially due to heightened activity of the maternal adrenal cortex [ 16 ]. The CRH is also synthesized in placental cells and the decidua, which further increases the adrenal secretion of cortisol [ 17 , 18 ]. Despite these elevated hormone levels, the maternal HPA axis becomes progressively less responsive to acute stressors across gestation, a phenomenon believed to be adaptive. This hypo-responsiveness helps protect the developing fetus from excessive exposure to maternal stress hormones, particularly cortisol [ 19 ]. For a short period, the human stress response is essential for survival and adaptation to new or challenging circumstances, helping to maintain physiological homeostasis [ 20 ]. However, prolonged or chronic activation of this system, termed chronic stress, can lead to dysregulation due to sustained stimulation. During pregnancy, this is of particular concern, as both the maternal and fetal systems are interlinked. On the one hand, the mother's psychological well-being is essential for a healthy pregnancy and a positive birth experience [ 21 ]. On the other hand, maternal stress can influence the unborn child even in utero. Beyond genetic inheritance, the fetus exhibits developmental plasticity that allows adaptation to environmental cues, a process called fetal programming [ 12 , 22 , 23 ]. High levels of maternal cortisol can cross the placental barrier and have been associated with impaired fetal growth and neurodevelopment [ 24 , 25 ]. Evidence also suggests that maternal stress activates the fetal ANS, resulting in observable physiological responses such as increased fetal heart rate variability and reduced motor activity [ 26 ]. In FELICITy-1 (Fetal EarLy non-Invasive biomarkers of chronic maternal stress during pregnancy resulting in alterations of infant CognItive development), Lobmaier et al. further demonstrated changes in fetal heart rate (fHR) in response to maternal stress. They developed a novel non-invasive biomarker of prenatal stress, the Fetal Stress Index (FSI), by incorporating maternal heart rate (mHR) dynamics [ 27 , 28 ]. A variety of strategies have been explored to reduce chronic stress, with growing interest in mind-body interventions. Among these, yoga has emerged as a promising holistic practice that integrates physical postures (asanas), breathing techniques (pranayama), and meditation, offering benefits for both physical and psychological well-being [ 29 ]. Two widely practiced forms are Yoga Hatha, which emphasizes gentle movement and strength, and Yoga Nidra, a guided meditative relaxation. Yoga has been increasingly investigated as a non-pharmacological approach to alleviate prenatal stress. Several studies and meta-analyses have reported beneficial effects of yoga during pregnancy, including reductions in anxiety, depressive symptoms, and perceived stress, as well as improvements in quality of life and pregnancy-related pain. In a comprehensive review of 28 studies, Babbar and Shyken (2016) identified 17 randomized controlled trials (RCTs) demonstrating significant improvements in maternal well-being among yoga participants [ 30 ]. For example, Field et al. (2012) found that pregnant women with depressive symptoms who engaged in yoga and massage interventions reported greater reductions in depression, anxiety, anger, and physical discomfort than those receiving standard care [ 31 ]. An Indian RCT involving high-risk pregnancies found significantly lower stress levels and greater satisfaction during pregnancy following a 16-week meditative yoga intervention compared to a stretching control group [ 32 ]. The only European RCT included in the review, conducted in the UK, reported reduced cortisol levels and lower pregnancy-specific anxiety in the yoga group, although no significant effects were observed for postpartum depression [ 33 ]. More recently, reviews by Kwon et al. (2020) and Corrigan et al. (2022) similarly reported positive outcomes such as reduced anxiety, stress, depression, and pain in comparison to standard prenatal care. However, both reviews conclude that more research in this field is needed [ 34 , 35 ]. Still, the interpretation of existing data is limited by methodological heterogeneity. Many studies lacked adequate control groups or employed active comparators such as walking or bonding workshops. Furthermore, variations in yoga style, frequency, duration, and timing of intervention initiation complicate cross-study comparisons. Notably, most available evidence stems from studies conducted in Asian settings, where yoga is culturally ingrained. This raises questions about the generalizability of findings to Western healthcare contexts. To address this gap, the present study aimed to evaluate the impact of a well-designed prenatal yoga program, initiated early in pregnancy, on maternal stress within a European population, using both subjective and objective outcome measures. Methods Design and setting The FELICITy-2 study is a prospective quasi-randomized controlled trial that was carried out from December 2022 to May 2024 at the TUM University Hospital, Munich, Germany. Ethics approval and consent to participate The study was conducted in compliance with the ethical guidelines by the Committee of Ethical Principles for Medical Research from the Technical University of Munich (TUM) and received approval from the “Ethikkommission der Fakultät für Medizin der TUM” (reference number 2022-86-S-SR). It is officially registered in the German Clinical Trials Register (DRKS) under the identifier DRKS00037529 and is publicly accessible at https://www.drks.de/DRKS00037529. After screening, providing study information, and a personal briefing, written informed consent was obtained from all participants. Recruitment and sampling For recruitment purposes, this trial was disseminated via the TUM University Hospital homepage, referring physicians' practices, and the hospital “Dritter Orden”, Munich. Women who were interested in participating in the study contacted the research team via email, after which they were sent a screening questionnaire. The screening process involved the implementation of the Cohen Perceived Stress Scale-10 (PSS-10), a standardized instrument designed to identify individuals exhibiting elevated stress levels. A cutoff score of ≥ 19 was established, representing the 80th percentile of the PSS-10 according to Lobmaier et al. [27], and served as the primary inclusion criterion. In addition, participants had to be between 18 and 45 years old, between 12+0 and 20+0 weeks of gestation at the time of enrollment, have a singleton pregnancy, and be fluent in spoken and written German. Another requirement was that participants were willing to attend at least 75% of the available yoga sessions. Exclusion criteria were fetal malformations or profound placental alterations [36], fetal genetic disorders, maternal severe illness during pregnancy [37], preterm birth, and maternal drug or alcohol abuse. Group allocation Participants were then assigned to either the intervention or control group using a quasi-randomized procedure. Due to organizational challenges and a limited number of participants, the planned initial proper randomization could not be implemented. The study was therefore conducted in sequential waves, with group allocation determined by the order of enrollment and the availability of spots within each group. The assignment depended on the group capacity at the time of each participant’s inclusion. The study team had no influence on the timing of the participants' contact, and the participants were unaware of the allocation process; neither could they choose the group. Intervention An integrated yoga program was developed in collaboration with a certified prenatal yoga instructor for the intervention group, hereafter referred to as the yoga group. The yoga intervention began immediately upon study entry and continued until delivery. It consisted of two components: Yoga Hatha practice. It was offered weekly for 105 minutes in person at the TUM University Hospital. Each class focused on a specific theme relevant to pregnancy's physical and emotional needs, while following a similar structure. Sessions began with a 15-minute settling-in period in a restful position, followed by 15 minutes of breathing exercises (Pranayama) and meditation (Dhyāna) in a lying posture. This was followed by 45 minutes of active yoga practice (Asanas), designed to gently mobilize and strengthen the entire body. The session concluded with 15 minutes of calming meditation in a reclined position and a final 15-minute deep relaxation phase in Shavasana [38, 39]. Yoga Nidra sessions. They were conducted once weekly for 20 minutes via live online video classes. Each session was led by an instructor and followed a standardized sequence to induce deep physical and mental relaxation. Key elements included: preparing and relaxing the mind (in Shavasana); formulating mental intentions (Sankalpa, serving as a positive affirmation throughout the practice), awareness of the breath (breath counting, abdominal/chest breathing), body awareness scan (Nyasa), visualization of mental images (Chidākāsha), repetition of mental resolutions or intentions (Sankalpa), and gentle return to waking awareness [40, 41]. The control group received regular pregnancy care. Data collection Perceived Stress Scale-10 (PSS-10) and Prenatal Distress Questionnaire (PDQ) The primary aim of this study was to evaluate two stress-related questionnaires: the PSS-10 and the Prenatal Distress Questionnaire (PDQ). These were first collected upon inclusion in the study (PSS-10 used as a screening instrument), again at the time intervals of the second and third trimester screenings (between 18+0 and 21+6 weeks of gestation and between 28+0 and 31+6 weeks of gestation), and finally within one week after delivery (here, only the PSS-10 was used). The PSS-10 evaluates the extent to which individuals perceive their life circumstances over the past month as stressful [42]. This ten-item questionnaire addresses symptoms such as depression, anxiety, exhaustion, feeling overwhelmed, and general dissatisfaction. According to Yali and Lobel (1999), the PDQ measures pregnancy-specific concerns using twelve questions addressing topics such as body image, maternal and fetal health, childbirth, and interpersonal relationships [43]. Both questionnaires have been validated in German, and their use is recommended in clinical research [44, 45]. They are provided as Supplementary Material 1. Sociodemographic and health questionnaires At inclusion, participants completed a structured questionnaire covering sociodemographic, health-related, and obstetric information relevant to the study. The sociodemographic section covered age, education, employment status, and household income. The health-related section gathered data on pre-existing conditions, body mass index (BMI), physical activity, and the obstetric section included gestational age, parity, pregnancy intention (planned or unplanned), and any complications during pregnancy. The same inquiries regarding BMI, employment, and physical activity were incorporated into a concise follow-up questionnaire administered during the second and third trimester screening intervals to monitor any alterations throughout pregnancy. After delivery, a comprehensive set of clinically relevant maternal and neonatal data was recorded. This included the gestational age at birth, the mode of delivery, labor induction, as well as the newborn’s gender, birth weight, APGAR scores, and neonatal intensive care unit (NICU) admissions if applicable. The questionnaires developed by the researchers are available in Supplementary Material 2. Cortisol Hair samples were collected at enrollment and again within one week postpartum to measure cortisol concentrations. Following the Society of Hair Testing recommendations, a strand (~3 mm diameter) was cut close to the scalp at the occipital region. It was wrapped in aluminum foil for storage and transportation [46]. Fifty milligrams of hair from the three centimeters closest to the roots were analyzed, representing approximately the Cortisol levels of the last three months [47, 48]. The samples were sent to the Department of Biochemistry (Endocrinology section) at the Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Argentina, where cortisol concentrations were measured using automated chemiluminescent immunoassays [49]. Edinburgh Postpartum Depression Scale (EPDS) Between 6 and 8 weeks after delivery, the mother's postpartum mood was assessed using the Edinburgh Postpartum Depression Scale (EPDS), validated for the German language [50, 51]. Statistical methods The statistical analysis was performed using IBM SPSS Statistics (Version 29.0.1.0, IBM Corp., Armonk, NY, USA). The Shapiro–Wilk test was applied to assess the distribution of variables. In cases of non-normal distribution, results are presented as medians with interquartile ranges (IQR); for normally distributed data, means and standard deviations (SD) are reported. Categorical variables are described using absolute and percentage frequencies. Group comparisons were conducted using independent-samples t-tests (normal distribution), Mann-Whitney U tests (not normally distributed), and Fisher's exact tests. Within-group changes were analyzed using paired t-tests. Statistical significance is assumed for p < 0.05 and is indicated by an asterisk (*). Results Participants and baseline characteristics A total of 82 pregnant women were screened using the PSS-10 questionnaire. According to the established inclusion criteria, 33 participants were eligible, and data from 28 participants (14 per group) were ultimately included in the final analysis, as illustrated in Figure 2. There were no significant differences in maternal characteristics (reported in Table 1). The women enrolled in the study were predominantly highly educated and reported above-average incomes. At inclusion, many participants stated that they were generally physically active and had already been in contact with yoga practices. Table 1. Sociodemographic, obstetric, and health parameters at baseline. BMI: body mass index. ICSI: Intracytoplasmic sperm injection. IVF: in vitro fertilization. Data are presented as mean (SD), median (IQR), or n (%). *p < 0.05. Missing data: 1 one value missing. Characteristics Control n = 14 Yoga n = 14 p Maternal age (years) 35.2 (3.8) 33.3 (3.1) 0.157 Gestational age (weeks) 17.3 (3.4) 15.9 (3.0) 0.284 BMI pregestational (kg/m 2 ) 20.8 (1.9) 19.8 (19-23) 0.297 BMI at study entry (kg/m 2 ) 21.9 (2.5) 21.9 (3.4) 1 0.867 Working 10 (71) 12 (86) 0.648 University degree 10 (71) 14 (100) 0.098 Married 11 (79) 8 (57) 0.420 Net household income >5000€/month 9 (64) 8 (57) 1.000 European ethnicity 13 (93) 12 (86) 1.000 Multiparity 5 (36) 1 (7) 0.165 Planned pregnancy 12 (86) 12 (86) 1.000 IVF / ICSI / insemination 3 (21.4) 2 (14.3) 1.000 Use of psychoactive substances (tobacco, alcohol, illicit drugs) 0 0 Autoimmune disease 2 (14) 1 (7) 1.000 Antidepressants 0 1 (7) 1.000 Arterial hypertension 1 (7) 0 1.000 Sports activity before pregnancy 12 (86) 14 (100) 0.481 Previous experience with yoga prior to study enrollment 10 (71) 10 (71) 1.000 In the intervals of the second and third trimester screenings, overall engagement in physical activity was high in both groups, as detailed in Tables 2 and 3. The term "yoga study-organized" refers to the structured prenatal yoga sessions provided as part of the intervention for participants in the yoga group, while "yoga private-organized" encompasses any additional yoga practice pursued independently, such as attending in-person or online classes or engaging in self-guided routines at home. In the second and third trimesters, participants in the yoga group reported significantly higher levels of yoga activity, mainly due to regular participation in the study-organized sessions. They completed 13 Yoga Hatha classes (SD = 3) and 12 Yoga Nidra classes (SD = 3). The mean attendance rate was 76% (SD = 12%). Table 2. Sociodemographic, obstetric, and health parameters at the second-trimester screening interval. BMI: body mass index. Data presented as mean (SD), median (IQR), or n (%). *p < 0.05. Missing data: 1 two values missing. Characteristics Control n = 14 Yoga n = 14 p Gestational age (weeks) 20.8 (1.6) 19.5 (1.2) 1 0.034* Current BMI (kg/m 2 ) 22.4 (2.3) 21.8 (2.7) 1 0.549 Working 9 (64) 9 (75) 1 0.683 Sports activity (including yoga) 7 (50) 12 (100) 1 0.005* Yoga practice during study period 6 (43) 12 (100) 1 0.002* · Yoga study-organized 0 12 (100) 1 <0.001* · Yoga private-organized 6 (43) 3 (25) 1 0.429 Table 3. Sociodemographic, obstetric, and health parameters at the third-trimester screening interval. BMI: body mass index. Data presented as mean (SD), median (IQR), or n (%). *p < 0.05. No missing data. Characteristics Control n = 14 Yoga n = 14 p Gestational age (weeks) 30.1 (30-31) 29.2 (0.9) 0.009* Current BMI (kg/m 2 ) 24.4 (2.4) 23.7 (3.1) 0.274 Working 8 (57) 9 (64) 1.000 Sports activity (including yoga) 12 (86) 14 (100) 0.241 Yoga practice during study period 8 (57) 14 (100) 0.008* · Yoga study-organized 0 14 (100) <0.001* · Yoga private-organized 8 (57) 2 (14) 0.023* PSS-10, PDQ, and Cortisol In the control group, the mean PSS-10 score was 24.9 (4.8) at study entry and decreased to 17.9 (5.5) after birth, reflecting a significant reduction of 6.9 (8.1), p = 0.004*. The yoga group showed similar results, with an initial mean score of 24.8 (5.6) that dropped to 16.1 (4.5) post-delivery, yielding a significant difference of 8.6 (6.2), p < 0.001*. The dataset was complete across both groups. Regarding PDQ, the control group had a mean score of 18.9 (6.9) at study entry, which declined to 15.1 (6.5) in the third trimester, a significant reduction of 3.9 (5.6), p = 0.012*. In the yoga group, the mean PDQ score decreased from 21.1 (7.3) at study entry to 15.4 (4.4) in the third trimester, showing a significant change of 5.7 (6.4), p = 0.003*. There was no missing data in either group. When comparing the changes between the first and last measurements, the difference in PSS scores (ΔPSS) was -6.9 (8.1) in the control group and -8.6 (6.2) in the yoga group, with no statistically significant difference between the groups (p = 0.268). Similarly, for PDQ (ΔPDQ), the control group showed a change of -3.9 (5.6) compared to -5.7 (6.4) in the yoga group, also without a significant difference between both groups (p = 0.211). Comparing longitudinal data, a continuous reduction in stress levels from study entry (referred to as PSS 1 or PDQ 1) until delivery (marked PSS 4) was found (second trimester labeled as PSS 2 or PDQ 2, third trimester indicated as PSS 3 or PDQ 3). Group differences are summarized in Tables 4 and 5 and visualized in Figures 3 and 4. Table 4. Group comparison of the Cohen Perceived Stress Scale-10 (PSS-10) during study participation. Data are presented as mean (SD), median (IQR), or n (%). *p < 0.05. No missing data. PSS-10 Control n = 14 Yoga n = 14 p PSS 1 value at study enrollment Gestational age (weeks) at evaluation 24.9 (4.8) 16.2 (3.6) 22.5 (20-28) 15.0 (3.1) 0.828 0.360 PSS 2 value at second trimester screening Gestational age (weeks) at evaluation 21.1 (5.5) 20.8 (2.0) 22.3 (6.5) 19.9 (1.3) 0.311 0.160 PSS 3 value at third trimester screening Gestational age (weeks) at evaluation 17.0 (5.5) 30.1 (0.8) 16.6 (4.5) 29.2 (0.9) 0.426 0.011* PSS 4 value within one week after delivery Days after delivery at evaluation 17.9 (5.5) 1 (1-2.25) 16.1 (4.5) 1 (0-1.25) 0.177 0.170 Table 5. Group comparison of the Prenatal Distress Questionnaire (PDQ) during study participation. Data are presented as mean (SD), median (IQR), or n (%). *p < 0.05. No missing data. PDQ Control n = 14 Yoga n = 14 p PDQ 1 value at study enrollment Gestational age (weeks) at evaluation 18.9 (6.9) 17.3 (3.4) 21.0 (7.3) 15.9 (3.0) 0.431 0.284 PDQ 2 value at second trimester screening Gestational age (weeks) at evaluation 15.8 (7.1) 21.3 (1.5) 18.3 (6.0) 20.0 (1.4) 0.161 0.032* PDQ 3 value at third trimester screening Gestational age (weeks) at evaluation 15.1 (6.5) 30.1 (0.8) 15.4 (4.4) 29.2 (0.9) 0.446 0.011* Regarding cortisol in hair samples (pg/mg), both groups demonstrated a significant decrease in cortisol levels from the first measurement at enrollment (“Cortisol 1”, at 17.4 (3.9) weeks of gestation) to the second measurement (“Cortisol 2”, at 1 (0-1.75) days postpartum), as illustrated in Figure 5. In-group comparison showed: at study entry, cortisol mean values of the control group measured 97.6 (56.4), and after birth, it was 35.8 (41.7), with a mean value difference of 61.8 (46.8), p = 0.005*. The yoga group started with a slightly higher cortisol level, with a cortisol mean value of 104.5 (40.6), and shows a steeper decline with a mean value of 40.0 (20.2) after birth; mean value difference 64.8 (38.3), p < 0.001*. For Cortisol 1, five data points were missing in the control group and one in the yoga group. The dataset was complete for Cortisol 2. Comparing between groups, the change in cortisol levels (ΔCortisol) between enrollment and postpartum was -61.78 (46.79) in the control group and -64.46 (38.36) in the yoga group, with no statistically significant difference (p = 0.443). Perinatal clinical outcome A subsequent comparison of the maternal and newborn characteristics after birth in both groups revealed no significant differences (see Table 6). Gestational age at birth, birth weight, APGAR scores, and blood gas values were similar in both groups. The EPDS score in the control group was 7.43 (5.85) at 8.1 (6.9-8.9) weeks postpartum, compared to 7.21 (3.64) in the yoga group at 7.6 (1.8) weeks postpartum. EDPS differences were not significantly different between the two groups (p = 0.454). Table 6. Maternal and neonatal clinical outcomes. NICU: neonatal care unit. Data are presented as mean (SD), median (IQR), or n (%). *p < 0.05. Missing data: 1 one value missing, 2 two values missing, 3 three values missing, 4 four values missing, 5 six values missing, 6 nine values missing. Characteristics Control n = 14 Yoga n = 14 p Gestational age at delivery (weeks) 40.0 (39-41) 39.9 (1.0) 0.593 Vaginal birth 12 (86) 7 (50) 0.052 Labor induction 5 (36) 1 4 (29) 1 1.000 Analgesia during birth 8 (57) 2 9 (64) 2 0.243 Lung maturity 0 0 - Gender newborn: female 6 (43) 8 (57) 0.706 1min APGAR 8 (1.3) 1 8 (1.9) 1 0.436 5min APGAR 9 (1.0) 10 (0.9) 0.855 10min APGAR 10 (0.4) 10 (0.6) 0.596 5min APGAR lower 7 0 0 - Admission to NICU 2 (14) 1 0 0.222 Umbilical cord pH (arterial) 7.24 (0.05) 7.29 (0.07) 0.040* Umbilical cord pH (venous) 7.35 (0.06) 4 7.37 (0.07) 4 0.421 pO2 arterial (mmHg) 20.7 (7.5) 5 26.0 (12.6) 3 0.304 pCO2 arterial (mmHg) 52.9 (6.9) 5 44.9 (11.1) 3 0.090 Glucose arterial (mg/dl) 92 (5) 6 81 (14) 5 0.130 Birth weight (g) 3487 (387) 3373 (423) 0.464 Birth weight percentile 55 (22) 1 40 (27) 1 0.148 Length newborn (cm) 52 (2.8) 52 (2.4) 0.886 Head circumference newborn (cm) 36 (1.2) 34 (1.1) 0.004* Discussion Principal findings The data presented above indicate that both groups, those participating in the structured prenatal yoga program and those receiving standard care, experienced significant reductions in perceived stress (PSS-10), pregnancy-specific distress (PDQ), and biological stress markers (hair cortisol) throughout pregnancy. Although the yoga group consistently demonstrated slightly greater improvements, the differences between the yoga and control groups did not reach statistical significance. This suggests that while yoga may offer added benefit, other factors or coping mechanisms may have contributed to a comparable effect in the control group. These patterns are clearly illustrated in the visual representations of the longitudinal data. Figure 3 shows a steady decline in PSS-10 scores in both groups up to the fourth measurement point (PSS 4, after delivery). While stress levels slightly increased again in the control group at this stage, they remained low in the yoga group. However, this difference was not statistically significant. Similarly, Figures 4 and 5, which track pregnancy-specific distress and hair cortisol concentrations, reflect a continuous decrease across all evaluation points in both groups. Potential mechanisms of yoga on the stress system Despite the absence of statistically significant group differences in stress reduction, pursuing the mechanisms by which yoga might promote health remains essential. One such pathway involves the downregulation of the HPA axis and the ANS. Although the exact physiological processes are not yet fully understood, studies suggest that regular yoga can increase vagal activity and promote parasympathetic dominance, a state associated with improved stress regulation [52, 53]. This autonomic shift may be especially beneficial during pregnancy, a period marked by extensive hormonal and emotional changes. Excessive sympathetic activation has been linked to increased risks of preterm birth, preeclampsia, and low birth weight [54]. Additionally, recent studies indicate that yoga may exert anti-inflammatory effects by reducing markers such as interleukin-6 (IL-6) and C-reactive protein (CRP), which are associated with chronic stress and potentially adverse pregnancy outcomes [55]. The social dimension of group yoga should also be acknowledged. Participation promotes social connectedness and peer support, which are protective against psychological distress and linked to reduced perinatal anxiety and depression [56-58]. Therefore, it is plausible that some of yoga’s positive effects are also through social interactions. Explanation for attenuated effect sizes - gestational adaptation Given the influence of yoga and the effects explored in this context, it is important to reflect on why, in this trial, the observed impact of yoga on stress was moderated. What needs to be discussed is whether there is a natural decline in perceived stress as gestation progresses. This phenomenon may, in part, reflect psychological adaptation to pregnancy, increasing preparation for childbirth, and the availability of growing social and medical support during later stages of gestation. Supporting this, several findings show that women adjust their coping strategies throughout pregnancy, with more consistent use of planning and increasing reliance on spiritual coping, suggesting an adaptive stress management process [56, 59, 60]. This natural decline may explain the observed reductions in stress markers (PSS-10, PDQ, cortisol) in both groups. However, other findings challenge this perspective. A recent longitudinal study found that perceived stress levels, measured using the PSS-10, were significantly higher in the third trimester compared to the first and second, regardless of parity or prior miscarriage [61]. From a physiological perspective, it becomes clear that only the stress response of pregnant women is dampened, while there is a progressive increase in placental CRH, as well as ACTH and cortisol levels throughout pregnancy. The weakened response to stress can be explained by a downregulation of receptor sensitivity and increased activity of the placental enzyme 11β-hydroxysteroid dehydrogenase type 2 (11ß-HSD2), which converts cortisol into its inactive form, cortisone. This leads to a reduced transfer of cortisol into the fetal circulation [62]. Methodological considerations The study design and sample characteristics must be considered when interpreting the results. The participants’ characteristics were very one-sided. These were predominantly physically active, highly educated women of European background with above-average household incomes. This homogeneity may limit the generalizability of the findings. Interestingly, this sample composition contrasts with results from the FELICITy-1 study by Lobmaier et al. (2022), which found that within their subgroup of highly stressed pregnant women, participants were significantly less likely to hold a university degree or report a monthly household income above 5000€ [27]. Similar findings were reported, which also observed that pregnant women with lower socioeconomic status were more vulnerable to stress, anxiety, and depression [63]. Furthermore, due to the language-based inclusion criteria, non-German-speaking individuals were excluded from participation. This aspect also limits the sample's representativeness, particularly considering the multicultural demographic of Munich (and Germany). A possible confounder in assessing the effectiveness of the yoga intervention is the generally high level of physical activity reported in both the yoga and control groups. Moreover, some participants in the control group indicated that they practiced yoga independently during the study period. Although the study’s structured and supervised prenatal yoga sessions were likely more intensive and consistent, this overlap reduces the contrast between groups and may have reduced measurable group differences. Another critical aspect to consider is the inclusion criterion based on elevated perceived stress levels (PSS-10 ≥ 19), which preselected a sample already experiencing higher stress. While this approach ensured relevance to the intervention goal, it may also have introduced response bias. It is possible that some participants consciously or unconsciously exaggerated their baseline stress levels to qualify for participation in the study and gain access to the free yoga program. In turn, artificially elevated baseline scores may have contributed to the observed reduction in stress over time. Additionally, participants may have felt motivated to report improvements over time that were in line with the expected outcomes of the intervention [64, 65]. Finally, the small sample size represents a key limitation, as it restricted the statistical power and the ability to detect potential group differences. Unfortunately, organizational challenges and limited participant availability limited the number of participants who could be enrolled. In addition, recruitment constraints necessitated a quasi-randomized allocation procedure, which precluded proper randomization. This may have introduced systematic bias and limited the internal validity of the findings. Implications and contribution Although this study did not provide statistical evidence for the effectiveness of prenatal yoga in reducing stress, it contributes to the broader research landscape by applying a multimodal assessment approach in a Western population. One of the main strengths of this study lies in its prospective longitudinal design, which reduces recall bias by collecting data at predefined intervals throughout pregnancy [66]. Participants were observed at multiple defined time points during pregnancy. Specifically, data were gathered during the second and third trimesters, allowing for a dynamic, time-sensitive analysis of stress rather than a single-point assessment, as in FELICITy-1. This approach captures the general trends and individual fluctuations in stress levels throughout pregnancy. Another key advantage is the clinically-integrated yoga intervention, which was specifically designed for pregnant participants and implemented in cooperation with a certified prenatal yoga instructor. The course was adapted to pregnant women's needs and included breathing exercises, gentle stretching, and pelvic floor work. The standardized intervention helps control for confounding variables, such as variation in yoga instruction or style. Furthermore, stress was assessed using a combination of methods, including objective measures, such as hair cortisol concentrations, and subjective data from validated self-report questionnaires. This dual perspective is essential, as stress is a complex and multidimensional construct that is difficult to capture [67]. By combining physiological and subjective data, the study offers a more nuanced understanding of perinatal stress. Future research The findings of this trial offer a solid foundation and highlight the need for further research. Future studies should include larger and more diverse cohorts to detect meaningful effects and improve generalizability. Moreover, longitudinal follow-up of offspring development is essential. As planned in our study, standardized assessments like the Parent Report of Children’s Abilities-Revised (PARCA-R), which evaluates cognitive and language development during the first two years of life, may offer valuable insights into the potential long-term benefits of prenatal yoga. Finally, integrating prenatal yoga with complementary approaches, including psychological counseling, other mindfulness techniques, or digital health applications, could enhance maternal well-being. Systematic evaluation of such multimodal interventions may lead to comprehensive support throughout pregnancy and postpartum, benefiting both mother and child. Conclusion The FELICITy-2 study suggests that maternal stress levels decline throughout pregnancy, as evidenced by significant reductions in subjective stress measures (PSS-10, PDQ) and objective biological markers (hair cortisol) across all participants. Contrary to our hypothesis, no statistically significant differences between the yoga and control groups were found. Nevertheless, yoga has the potential to be a low-risk, non-pharmacological addition to standard prenatal care. We assume that simply increasing participants’ awareness of their stress and well-being during pregnancy contributed to the overall reduction in stress levels in both groups. Moreover, the homogeneous and physically active sample, as well as independent yoga practice among the control group, may have diluted the effects of the intervention. Future studies should further clarify yoga’s role in perinatal health. Declarations Data Availability Generated data from the study is not available for publicity because of possible links to participants, especially newborns’ identities, but it is available from the corresponding author at a reasonable request. Acknowledgments We are thankful for all female participants of the FELICITy-2 study, whom we could accompany during the extraordinary time of their pregnancy and early motherhood. Furthermore, we are grateful for the engagement of our yoga instructor, Anne Loewer, leading the empowering yoga course for our intervention group. We want to thank everyone who contributed to the recruitment of participants, especially PD Dr. F. Stumpfe of the hospital “Dritter Orden”, Munich. Authors’ contributions CB, MCA, and SML developed the study protocol and project. Participant recruitment, data collection, and management were performed by CB, MJEM, and SML. CB, MJEM, and SML conducted statistical analyses. BF and DG performed cortisol analysis in hair samples. Manuscript writing was led by CB and SML, with editing contributions from MJEM, MF, MCA, and SML. All authors read and approved the final manuscript. Funding Open access funding was enabled and organized by the project DEAL. Partial financial support was provided by the Institute for Advanced Studies at the Technical University of Munich (Hans Fischer Senior Fellowship for MCA) and the Dr. Geisenhofer Foundation, Munich, Germany. Additional funds from the TUM University Hospital, Department of Obstetrics and Gynecology, Munich, were utilized with the authorization of SML. Additional Information The author(s) declare no competing interests. Statement on the use of generative AI and AI-based tools To assist in the development of this work, the authors utilized ChatGPT (chat.openai.com) and Grammarly (grammarly.com) for minor language refinement and proofreading. All content was reviewed and revised by the authors, who assume full responsibility for the final version of the published article. References Thornburg, K. L., Jacobson, S-L., Giraud, G. D. & Morton, M. J. Hemodynamic changes in pregnancy. In: Seminars in perinatology. vol. 24: Elsevier; : 11–14. (2000). Hytten, F. Blood volume changes in normal pregnancy. Clin. Haematol. 14 (3), 601–612 (1985). Edelstein, R. S. et al. Prenatal hormones in first-time expectant parents: Longitudinal changes and within‐couple correlations. Am. J. Hum. Biology . 27 (3), 317–325 (2015). Bjelica, A., Cetkovic, N., Trninic-Pjevic, A. & Mladenovic-Segedi, L. The phenomenon of pregnancy—A psychological view. Ginekol. Pol. 89 (2), 102–106 (2018). Woods, S. M., Melville, J. L., Guo, Y., Fan, M-Y. & Gavin, A. Psychosocial stress during pregnancy. Am. J. Obstet. Gynecol. 202 (1), 61 (2010). e1–. e7. McEwen, B. S. Allostasis and allostatic load: implications for neuropsychopharmacology. Neuropsychopharmacology 22 (2), 108–124 (2000). Jansen, A. S., Van Nguyen, X., Karpitskiy, V., Mettenleiter, T. C. & Loewy, A. D. Central command neurons of the sympathetic nervous system: basis of the fight-or-flight response. Science 270 (5236), 644–646 (1995). Ross, A. & Thomas, S. The health benefits of yoga and exercise: a review of comparison studies. J. Altern. Complement. Med. 16 (1), 3–12 (2010). Mason, J. W. A review of psychoendocrine research on the pituitary-adrenal cortical system. Psychosom. Med. 30 (5), 576–607 (1968). Kirschbaum, C., Pirke, K-M. & Hellhammer, D. H. The ‘Trier Social Stress Test’–a tool for investigating psychobiological stress responses in a laboratory setting. Neuropsychobiology 28 (1–2), 76–81 (1993). Cohen, S., Kessler, R. C. & Gordon, L. U. Measuring stress: A guide for health and social scientists (Oxford University Press on Demand, 1997). Barker, D. J. The developmental origins of adult disease. J. Am. Coll. Nutr. 23 (6 Suppl), 588s–95s. 10.1080/07315724.2004.10719428 (2004). Rakers, F. et al. Transfer of maternal psychosocial stress to the fetus. Neurosci. Biobehavioral Reviews . 117 , 185–197 (2020). Fowden, A. L. Endocrine regulation of fetal growth. Reprod. Fertility Dev. 7 (3), 351–363 (1995). Kwon, E. J. & Kim, Y. J. What is fetal programming? a lifetime health is under the control of in utero health. Obstet. Gynecol. Sci. 60 (6), 506–519 (2017). DÖRR, H. G. et al. Longitudinal study of progestins, mineralocorticoids, and glucocorticoids throughout human pregnancy. J. Clin. Endocrinol. Metabolism . 68 (5), 863–868 (1989). Mastorakos, G. & Ilias, I. Maternal and fetal hypothalamic-pituitary‐adrenal axes during pregnancy and postpartum. Ann. N. Y. Acad. Sci. 997 (1), 136–149 (2003). Huizink, A. C. Prenatal stress and its effect on infant development. (2000). Glynn, L. M., Davis, E. P. & Sandman, C. A. New insights into the role of perinatal HPA-axis dysregulation in postpartum depression. Neuropeptides 47 (6), 363–370 (2013). Chrousos, G. P. Stress and disorders of the stress system. Nat. reviews Endocrinol. 5 (7), 374–381 (2009). Curtis, K., Weinrib, A. & Katz, J. Systematic review of yoga for pregnant women: current status and future directions. Evidence-based complementary and alternative medicine. ;2012. (2012). Gluckman, P. D., Hanson, M. A., Cooper, C. & Thornburg, K. L. Effect of in utero and early-life conditions on adult health and disease. N. Engl. J. Med. 359 (1), 61–73 (2008). Schetter, C. D. & Tanner, L. Anxiety, depression and stress in pregnancy: implications for mothers, children, research, and practice. Curr. Opin. Psychiatry . 25 (2), 141–148 (2012). O’Donnell, K. J. & Meaney, M. J. Fetal origins of mental health: the developmental origins of health and disease hypothesis. Am. J. Psychiatry . 174 (4), 319–328 (2017). Gitau, R., Cameron, A., Fisk, N. M. & Glover, V. Fetal exposure to maternal cortisol. Lancet 352 (9129), 707–708 (1998). DiPietro, J. A., Costigan, K. A. & Gurewitsch, E. D. Fetal response to induced maternal stress. Early Hum. Dev. 74 (2), 125–138 (2003). Lobmaier, S. M. et al. Fetal heart rate variability responsiveness to maternal stress, non-invasively detected from maternal transabdominal ECG. Arch. Gynecol. Obstet. 301 (2), 405–414. 10.1007/s00404-019-05390-8 (2020). Antonelli, M. C. et al. Early Biomarkers and Intervention Programs for the Infant Exposed to Prenatal Stress. Curr. Neuropharmacol. 20 (1), 94–106. 10.2174/1570159x19666210125150955 (2022). Field, T. Yoga clinical research review. Complement. Ther. Clin. Pract. 17 (1), 1–8 (2011). Babbar, S. & Shyken, J. Yoga in pregnancy. Clin. Obstet. Gynecol. 59 (3), 600–612 (2016). Field, T. et al. Yoga and massage therapy reduce prenatal depression and prematurity. J. Bodyw. Mov. Ther. 16 (2), 204–209 (2012). Deshpande, C. et al. Yoga for High–Risk Pregnancy: A Randomized Controlled Trial. Annals Med. health Sci. Res. 3 (3), 341–344 (2013). Newham, J. J., Wittkowski, A., Hurley, J., Aplin, J. D. & Westwood, M. Effects of antenatal yoga on maternal anxiety and depression: a randomized controlled trial. Depress. Anxiety . 31 (8), 631–640 (2014). Kwon, R., Kasper, K., London, S. & Haas, D. M. A systematic review: The effects of yoga on pregnancy. Eur. J. Obstet. Gynecol. Reproductive Biology . 250 , 171–177 (2020). Corrigan, L., Moran, P., McGrath, N., Eustace-Cook, J. & Daly, D. The characteristics and effectiveness of pregnancy yoga interventions: a systematic review and meta-analysis. BMC pregnancy childbirth . 22 (1), 250 (2022). Gordijn, S. J. et al. Consensus definition of fetal growth restriction: a Delphi procedure. Ultrasound Obstet. Gynecol. 48 (3), 333–339. 10.1002/uog.15884 (2016). Kilpatrick, S. K. & Ecker, J. L. Severe maternal morbidity: screening and review. Am. J. Obstet. Gynecol. 215 (3), B17–22. 10.1016/j.ajog.2016.07.050 (2016). Iyengar, B. K., Menuhin, Y. & Mangoldt, U. Licht auf Yoga: Yoga-Dīpikā: das grundlegende Lehrbuch des Hatha-Yoga. (No Title). (1993). Quinker, D. Einfluss von Übungshäufigkeit und Yogastil auf die Gesundheit, den Lebensstil und die Sicherheit von Yogaübenden: eine Onlineumfrage. In.: Dissertation, Duisburg, Essen, Universität Duisburg-Essen, ; 2021. (2021). Pandi-Perumal, S. R. et al. The origin and clinical relevance of yoga nidra. Sleep. Vigilance . 6 (1), 61–84 (2022). Saraswati, S. S. & Hiti, J. K. Yoga nidra (Bihar School of Yoga Munger, 1984). Cohen, S., Kamarck, T. & Mermelstein, R. A global measure of perceived stress. J. Health Soc. Behav. 24 (4), 385–396 (1983). Yali, A. M. & Lobel, M. Coping and distress in pregnancy: an investigation of medically high risk women. J. Psychosom. Obstet. Gynaecol. 20 (1), 39–52. 10.3109/01674829909075575 (1999). Klein, E. M. et al. The German version of the Perceived Stress Scale–psychometric characteristics in a representative German community sample. BMC psychiatry . 16 , 1–10 (2016). Pluess, M., Bolten, M., Pirke, K-M. & Hellhammer, D. Maternal trait anxiety, emotional distress, and salivary cortisol in pregnancy. Biol. Psychol. 83 (3), 169–175 (2010). Cooper, G. A., Kronstrand, R. & Kintz, P. Society of Hair Testing guidelines for drug testing in hair. Forensic Sci. Int. 218 (1–3), 20–24 (2012). Karlén, J., Ludvigsson, J., Frostell, A., Theodorsson, E. & Faresjö, T. Cortisol in hair measured in young adults-a biomarker of major life stressors? BMC Clin. Pathol. 11 , 1–6 (2011). Iglesias, S. et al. Hair cortisol: A new tool for evaluating stress in programs of stress management. Life Sci. 141 , 188–192. 10.1016/j.lfs.2015.10.006 (2015). Gonzalez, D. et al. Hair cortisol measurement by an automated method. Sci. Rep. 9 (1), 8213 (2019). Cox, J. & Holden, J. Perinatal mental health: A guide to the Edinburgh Postnatal Depression Scale (EPDS) (Royal College of Psychiatrists, 2003). Bergant, A., Nguyen, T., Heim, K., Ulmer, H. & Dapunt, O. German language version and validation of the Edinburgh postnatal depression scale. Deutsche medizinische Wochenschrift 1998;123(3):35–40. (1946). Hayase, M. & Shimada, M. Effects of maternity yoga on the autonomic nervous system during pregnancy. J. Obstet. Gynaecol. Res. 44 (10), 1887–1895. 10.1111/jog.13729 (2018). Streeter, C. C., Gerbarg, P. L., Saper, R. B., Ciraulo, D. A. & Brown, R. P. Effects of yoga on the autonomic nervous system, gamma-aminobutyric-acid, and allostasis in epilepsy, depression, and post-traumatic stress disorder. Med. Hypotheses . 78 (5), 571–579 (2012). Christian, L. M. Physiological reactivity to psychological stress in human pregnancy: current knowledge and future directions. Prog. Neurobiol. 99 (2), 106–116 (2012). Kiecolt-Glaser, J. K. et al. Stress, inflammation, and yoga practice. Biopsychosoc. Sci. Med. 72 (2), 113–121 (2010). Yali, A. M. & Lobel, M. Stress-resistance resources and coping in pregnancy. Anxiety Stress Coping . 15 (3), 289–309 (2002). Razurel, C. & Kaiser, B. The role of satisfaction with social support on the psychological health of primiparous mothers in the perinatal period. Women health . 55 (2), 167–186 (2015). Collins, N. L., Dunkel-Schetter, C., Lobel, M. & Scrimshaw, S. C. Social support in pregnancy: psychosocial correlates of birth outcomes and postpartum depression. J. Personal. Soc. Psychol. 65 (6), 1243 (1993). Hamilton, J. G. & Lobel, M. Types, patterns, and predictors of coping with stress during pregnancy: Examination of the Revised Prenatal Coping Inventory in a diverse sample. J. Psychosom. Obstet. Gynecol. 29 (2), 97–104 (2008). Dunkel Schetter, C. Psychological science on pregnancy: stress processes, biopsychosocial models, and emerging research issues. Ann. Rev. Psychol. 62 (1), 531–558 (2011). Redondo, M. M., Liebana-Presa, C., Pérez-Rivera, J., Martín-Vázquez, C. & Calvo-Ayuso, N. García-Fernández R. Exploring Self-Perceived Stress and Anxiety Throughout Pregnancy: A Longitudinal Study. Diseases 13 (4), 121 (2025). Entringer, S. et al. Attenuation of maternal psychophysiological stress responses and the maternal cortisol awakening response over the course of human pregnancy. Stress 13 (3), 258–268 (2010). Nagandla, K. et al. Prevalence and associated risk factors of depression, anxiety and stress in pregnancy. Int. J. Reprod. Contracept. Obstet. Gynecol. 5 (7), 2380–2389 (2016). Podsakoff, P. M., MacKenzie, S. B., Lee, J-Y. & Podsakoff, N. P. Common method biases in behavioral research: a critical review of the literature and recommended remedies. J. Appl. Psychol. 88 (5), 879 (2003). Orne, M. T. On the social psychology of the psychological experiment: With particular reference to demand characteristics and their implications. In: Sociological methods. Routledge; 279–299. (2017). Hassan, E. Recall bias can be a threat to retrospective and prospective research designs. Internet J. Epidemiol. 3 (2), 339–412 (2006). Kopp, M. S. et al. Measures of stress in epidemiological research. J. Psychosom. Res. 69 (2), 211–225 (2010). Additional Declarations No competing interests reported. Supplementary Files Add1PSSPDQ.pdf Supplementary Material 1 Title: Cohen Perceived Stress Scale (PSS-10) and Pregnancy Distress Questionnaire (PDQ) Description: This file contains the original questionnaires used to assess perceived stress and pregnancy-related distress during the study. Add2characteristics.pdf Supplementary Material 2 Title: Sociodemographic and health questionnaires Description: This file includes the baseline questionnaire on sociodemographic, health-related, and obstetric information, the follow-up questionnaires from the second and third trimester assessments, and a table documenting maternal and neonatal outcomes after birth. 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07:48:40","extension":"xml","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":158894,"visible":true,"origin":"","legend":"","description":"","filename":"3db03f5be62b42aeb9e773774d403b821structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/f34868f415174d262df7275e.xml"},{"id":97660456,"identity":"b7a09152-7d82-45f5-ad54-fef30e1b39ca","added_by":"auto","created_at":"2025-12-08 07:48:40","extension":"html","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":176790,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/c5da36a4b625a74ff52f46aa.html"},{"id":97660433,"identity":"529bb624-b955-44e8-9795-4eb6c03195fb","added_by":"auto","created_at":"2025-12-08 07:48:40","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":74673,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic illustration of the FELICITy-2 methods.\u003c/p\u003e\n\u003cp\u003eFigure 1 presents an overview of the FELICITy-2 study design with a timeline from pregnancy to postpartum. It includes the intervention and control arms, the time points when data were collected, and the types of data gathered at each stage.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/7015a33414a0d61026a3e4ac.png"},{"id":97660435,"identity":"db388ee5-ac4d-4b43-8245-3489ccafe934","added_by":"auto","created_at":"2025-12-08 07:48:40","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":25494,"visible":true,"origin":"","legend":"\u003cp\u003eRecruitment flow chart.\u003c/p\u003e\n\u003cp\u003eScreening, eligibility assessment, group allocation, and final numbers included in the analysis are shown.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/bba44794c5645d585d6f8e08.png"},{"id":97660437,"identity":"abb60c49-c4f4-4864-83b9-ca9de52cd147","added_by":"auto","created_at":"2025-12-08 07:48:40","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":24991,"visible":true,"origin":"","legend":"\u003cp\u003eLongitudinal progression of the Cohen Perceived Stress Scale (PSS-10).\u003c/p\u003e\n\u003cp\u003ePSS-10 scores in yoga and control groups at different evaluation points: PSS 1 at enrollment, PSS 2 during the second trimester screening interval, PSS 3 during the third trimester screening interval, PSS 4 within one week after delivery. Data are shown as medians with interquartile ranges and overall ranges.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/3e1a7f430d700d0ca94b458b.png"},{"id":97672928,"identity":"e4632b3e-e87b-4304-8f34-eced21d2bce2","added_by":"auto","created_at":"2025-12-08 09:39:05","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":22406,"visible":true,"origin":"","legend":"\u003cp\u003eLongitudinal progression of the Prenatal Distress Questionnaire (PDQ).\u003c/p\u003e\n\u003cp\u003ePDQ scores in yoga and control groups at different evaluation points: PDQ 1 at enrollment, PDQ 2 during the second trimester screening interval, PDQ 3 during the third trimester screening interval. Results are presented as medians with interquartile ranges and overall ranges.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/f7997a6aff98747df264c3c7.png"},{"id":97674975,"identity":"b668d8b4-ff5f-436a-95dd-15616560dcf9","added_by":"auto","created_at":"2025-12-08 09:45:05","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":22199,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal dynamics of cortisol concentrations in hair sample (pg/mg).\u003c/p\u003e\n\u003cp\u003eCortisol concentrations in yoga and control groups at different evaluation points: Cortisol 1 at enrollment, Cortisol 2 within one week after delivery. Results are presented as medians with interquartile ranges and overall ranges.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/954763ce75960a0e139ef4b5.png"},{"id":97678811,"identity":"4378b310-4956-4d12-a7c0-db886bb94b35","added_by":"auto","created_at":"2025-12-08 09:56:13","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1155735,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/0308c89b-514b-4d4d-a85b-e01cfbaebf2b.pdf"},{"id":97660434,"identity":"bd84edaf-514c-485b-b394-cae277a737d7","added_by":"auto","created_at":"2025-12-08 07:48:40","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":90584,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Material 1\u003c/p\u003e\n\u003cp\u003eTitle: Cohen Perceived Stress Scale (PSS-10) and Pregnancy Distress Questionnaire (PDQ)\u003c/p\u003e\n\u003cp\u003eDescription: This file contains the original questionnaires used to assess perceived stress and pregnancy-related distress during the study.\u003c/p\u003e","description":"","filename":"Add1PSSPDQ.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/c29df8919878960b149ec948.pdf"},{"id":97660441,"identity":"b57aa8d8-9af9-4fde-b4a6-510c60d56b87","added_by":"auto","created_at":"2025-12-08 07:48:40","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":114702,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Material 2\u003c/p\u003e\n\u003cp\u003eTitle: Sociodemographic and health questionnaires\u003c/p\u003e\n\u003cp\u003eDescription: This file includes the baseline questionnaire on sociodemographic, health-related, and obstetric information, the follow-up questionnaires from the second and third trimester assessments, and a table documenting maternal and neonatal outcomes after birth.\u003c/p\u003e","description":"","filename":"Add2characteristics.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7366549/v1/3b927bb5ccb1507a7ea7d793.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Prenatal yoga for stress reduction: results from the FELICITy-2 quasi-randomized controlled trial","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePregnancy is accompanied by profound biopsychosocial adaptations, including weight gain and increased blood volume [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], hormonal fluctuations [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], lifestyle adjustments, and shifts in interpersonal relationships [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Such simultaneous transformations often precipitate stress: up to 78% of pregnant women report slighttomoderate stress, and around 6% experience high stress levels [5].\u003c/p\u003e\u003cp\u003eStress can be defined as the perception of specific stimuli that cause physiological or psychological responses in an individual [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. These triggers, referred to as \u0026ldquo;stressors\u0026rdquo;, may arise from environmental, psychological, or physiological origins. The \u0026ldquo;stress response\u0026rdquo; is understood as the adaptive reaction to stressors. According to the classic \u0026ldquo;fight or flight\u0026rdquo; model, the body mobilizes energy resources [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. On a biochemical level, stress responses are primarily modulated by the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS). The hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary gland to produce adrenocorticotropic hormone (ACTH). This leads to the adrenal secretion of cortisol as a delayed reaction. At the same time, the ANS, particularly the sympathetic branch, is activated, immediately releasing catecholamines like adrenaline and noradrenaline [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In addition to these classical pathways, reactive oxygen species, cytokines, and serotonin have also been identified as physiological mediators involved in the stress response [\u003cspan additionalcitationids=\"CR13 CR14\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eIn the context of prenatal stress, pregnancy-related concerns are added to the general stress. As pregnancy progresses, cortisol production increases substantially due to heightened activity of the maternal adrenal cortex [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The CRH is also synthesized in placental cells and the decidua, which further increases the adrenal secretion of cortisol [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Despite these elevated hormone levels, the maternal HPA axis becomes progressively less responsive to acute stressors across gestation, a phenomenon believed to be adaptive. This hypo-responsiveness helps protect the developing fetus from excessive exposure to maternal stress hormones, particularly cortisol [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eFor a short period, the human stress response is essential for survival and adaptation to new or challenging circumstances, helping to maintain physiological homeostasis [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, prolonged or chronic activation of this system, termed chronic stress, can lead to dysregulation due to sustained stimulation. During pregnancy, this is of particular concern, as both the maternal and fetal systems are interlinked. On the one hand, the mother's psychological well-being is essential for a healthy pregnancy and a positive birth experience [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. On the other hand, maternal stress can influence the unborn child even in utero. Beyond genetic inheritance, the fetus exhibits developmental plasticity that allows adaptation to environmental cues, a process called fetal programming [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. High levels of maternal cortisol can cross the placental barrier and have been associated with impaired fetal growth and neurodevelopment [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Evidence also suggests that maternal stress activates the fetal ANS, resulting in observable physiological responses such as increased fetal heart rate variability and reduced motor activity [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. In FELICITy-1 (Fetal EarLy non-Invasive biomarkers of chronic maternal stress during pregnancy resulting in alterations of infant CognItive development), Lobmaier et al. further demonstrated changes in fetal heart rate (fHR) in response to maternal stress. They developed a novel non-invasive biomarker of prenatal stress, the Fetal Stress Index (FSI), by incorporating maternal heart rate (mHR) dynamics [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA variety of strategies have been explored to reduce chronic stress, with growing interest in mind-body interventions. Among these, yoga has emerged as a promising holistic practice that integrates physical postures (asanas), breathing techniques (pranayama), and meditation, offering benefits for both physical and psychological well-being [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Two widely practiced forms are Yoga Hatha, which emphasizes gentle movement and strength, and Yoga Nidra, a guided meditative relaxation.\u003c/p\u003e\u003cp\u003eYoga has been increasingly investigated as a non-pharmacological approach to alleviate prenatal stress. Several studies and meta-analyses have reported beneficial effects of yoga during pregnancy, including reductions in anxiety, depressive symptoms, and perceived stress, as well as improvements in quality of life and pregnancy-related pain. In a comprehensive review of 28 studies, Babbar and Shyken (2016) identified 17 randomized controlled trials (RCTs) demonstrating significant improvements in maternal well-being among yoga participants [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. For example, Field et al. (2012) found that pregnant women with depressive symptoms who engaged in yoga and massage interventions reported greater reductions in depression, anxiety, anger, and physical discomfort than those receiving standard care [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. An Indian RCT involving high-risk pregnancies found significantly lower stress levels and greater satisfaction during pregnancy following a 16-week meditative yoga intervention compared to a stretching control group [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. The only European RCT included in the review, conducted in the UK, reported reduced cortisol levels and lower pregnancy-specific anxiety in the yoga group, although no significant effects were observed for postpartum depression [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. More recently, reviews by Kwon et al. (2020) and Corrigan et al. (2022) similarly reported positive outcomes such as reduced anxiety, stress, depression, and pain in comparison to standard prenatal care. However, both reviews conclude that more research in this field is needed [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eStill, the interpretation of existing data is limited by methodological heterogeneity. Many studies lacked adequate control groups or employed active comparators such as walking or bonding workshops. Furthermore, variations in yoga style, frequency, duration, and timing of intervention initiation complicate cross-study comparisons. Notably, most available evidence stems from studies conducted in Asian settings, where yoga is culturally ingrained. This raises questions about the generalizability of findings to Western healthcare contexts.\u003c/p\u003e\u003cp\u003eTo address this gap, the present study aimed to evaluate the impact of a well-designed prenatal yoga program, initiated early in pregnancy, on maternal stress within a European population, using both subjective and objective outcome measures.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eDesign and\u0026nbsp;setting\u003c/p\u003e\n\u003cp\u003eThe FELICITy-2 study is a prospective quasi-randomized controlled trial that was carried out from December 2022 to May 2024 at the TUM University Hospital, Munich, Germany.\u003c/p\u003e\n\u003cp\u003eEthics approval and consent to participate\u003c/p\u003e\n\u003cp\u003eThe study was conducted in compliance with the ethical guidelines by the Committee of Ethical Principles for Medical Research from the Technical University of Munich (TUM) and received approval from the \u0026ldquo;Ethikkommission der Fakult\u0026auml;t f\u0026uuml;r Medizin der TUM\u0026rdquo; (reference number 2022-86-S-SR). It is officially registered in the German Clinical Trials Register (DRKS) under the identifier DRKS00037529 and is publicly accessible at\u0026nbsp;https://www.drks.de/DRKS00037529. After screening, providing study information, and a personal briefing, written informed consent was obtained from all participants.\u003c/p\u003e\n\u003cp\u003eRecruitment and sampling\u003c/p\u003e\n\u003cp\u003eFor recruitment purposes, this trial was disseminated via the TUM University Hospital homepage, referring physicians\u0026apos; practices, and the hospital \u0026ldquo;Dritter Orden\u0026rdquo;, Munich. Women who were interested in participating in the study contacted the research team via email, after which they were sent a screening questionnaire. The screening process involved the implementation of the Cohen Perceived Stress Scale-10 (PSS-10), a standardized instrument designed to identify individuals exhibiting elevated stress levels. A cutoff score of\u0026nbsp;\u0026ge;\u0026nbsp;19 was established, representing the 80th percentile of the PSS-10 according to Lobmaier et al. [27], and served as the primary inclusion criterion.\u003c/p\u003e\n\u003cp\u003eIn addition, participants had to be between 18 and 45 years old, between 12+0 and 20+0 weeks of gestation at the time of enrollment, have a singleton pregnancy, and be fluent in spoken and written German. Another requirement was that participants were willing to attend at least 75% of the available yoga sessions.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eExclusion criteria were fetal malformations or profound placental alterations [36], fetal genetic disorders, maternal severe illness during pregnancy [37], preterm birth, and maternal drug or alcohol abuse.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGroup allocation\u003c/p\u003e\n\u003cp\u003eParticipants were then assigned to either the intervention or control group using a quasi-randomized procedure.\u0026nbsp;Due to organizational challenges and a limited number of participants, the planned initial proper randomization could not be implemented. The study was therefore conducted in sequential waves, with group allocation determined by the order of enrollment and the availability of spots within each group. The assignment depended on the group capacity at the time of each participant\u0026rsquo;s inclusion.\u0026nbsp;The study team had no influence on the timing of the participants\u0026apos; contact, and the participants were unaware of the allocation process; neither could they choose the group.\u003c/p\u003e\n\u003cp\u003eIntervention\u003c/p\u003e\n\u003cp\u003eAn integrated yoga program was developed in collaboration with a certified prenatal yoga instructor for the intervention group, hereafter referred to as the yoga group. The yoga intervention began immediately upon study entry and continued until delivery. It consisted of two components:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eYoga Hatha practice. It was offered weekly for 105 minutes in person at the TUM University Hospital. Each class focused on a specific theme relevant to pregnancy\u0026apos;s physical and emotional needs, while following a similar structure. Sessions began with a 15-minute settling-in period in a restful position, followed by 15 minutes of breathing exercises (Pranayama) and meditation (Dhyāna) in a lying posture. This was followed by 45 minutes of active yoga practice (Asanas), designed to gently mobilize and strengthen the entire body. The session concluded with 15 minutes of calming meditation in a reclined position and a final 15-minute deep relaxation phase in Shavasana [38, 39].\u003c/li\u003e\n \u003cli\u003eYoga Nidra sessions. They were conducted once weekly for 20 minutes via live online video classes. Each session was led by an instructor and followed a standardized sequence to induce deep physical and mental relaxation. Key elements included: preparing and relaxing the mind (in Shavasana); formulating mental intentions (Sankalpa, serving as a positive affirmation throughout the practice), awareness of the breath (breath counting, abdominal/chest breathing), body awareness scan (Nyasa), visualization of mental images (Chidākāsha), repetition of mental resolutions or intentions (Sankalpa), and gentle return to waking awareness [40, 41].\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eThe control group received regular pregnancy care.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eData collection\u003c/p\u003e\n\u003cp\u003ePerceived Stress Scale-10 (PSS-10) and Prenatal Distress Questionnaire (PDQ)\u003c/p\u003e\n\u003cp\u003eThe primary aim of this study was to evaluate two stress-related questionnaires: the PSS-10 and the Prenatal Distress Questionnaire (PDQ). These were first collected upon inclusion in the study (PSS-10 used as a screening instrument), again at the time intervals of the second and third trimester screenings (between 18+0 and 21+6 weeks of gestation and between 28+0 and 31+6 weeks of gestation), and finally within one week after delivery (here, only the PSS-10 was used). The PSS-10 evaluates the extent to which individuals perceive their life circumstances over the past month as stressful [42]. This ten-item questionnaire addresses symptoms such as depression, anxiety, exhaustion, feeling overwhelmed, and general dissatisfaction. According to Yali and Lobel (1999), the PDQ measures pregnancy-specific concerns using twelve questions addressing topics such as body image, maternal and fetal health, childbirth, and interpersonal relationships [43]. Both questionnaires have been validated in German, and their use is recommended in clinical research [44, 45]. They are provided as Supplementary Material 1.\u003c/p\u003e\n\u003cp\u003eSociodemographic and health questionnaires\u003c/p\u003e\n\u003cp\u003eAt inclusion, participants completed a structured questionnaire covering sociodemographic, health-related, and obstetric information relevant to the study. The sociodemographic section covered age, education, employment status, and household income. The health-related section gathered data on pre-existing conditions, body mass index (BMI), physical activity, and the obstetric section included gestational age, parity, pregnancy intention (planned or unplanned), and any complications during pregnancy. The same inquiries regarding BMI, employment, and physical activity were incorporated into a concise follow-up questionnaire administered during the second and third trimester screening intervals to monitor any alterations throughout pregnancy. After delivery, a comprehensive set of clinically relevant maternal and neonatal data was recorded. This included the gestational age at birth, the mode of delivery, labor induction, as well as the newborn\u0026rsquo;s gender, birth weight, APGAR scores, and neonatal intensive care unit (NICU) admissions if applicable. The questionnaires developed by the researchers are available in Supplementary Material 2.\u003c/p\u003e\n\u003cp\u003eCortisol\u003c/p\u003e\n\u003cp\u003eHair samples were collected at enrollment and again within one week postpartum to measure cortisol concentrations. Following the Society of Hair Testing recommendations, a strand (~3 mm diameter) was cut close to the scalp at the occipital region. It was wrapped in aluminum foil for storage and transportation [46]. Fifty milligrams of hair from the three centimeters closest to the roots were analyzed, representing approximately the Cortisol levels of the last three months [47, 48]. The samples were sent to the Department of Biochemistry (Endocrinology section) at the Faculty of Pharmacy and Biochemistry, University of Buenos Aires, Argentina, where cortisol concentrations were measured using automated chemiluminescent immunoassays [49].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEdinburgh Postpartum Depression Scale (EPDS)\u003c/p\u003e\n\u003cp\u003eBetween 6 and 8 weeks after delivery, the mother\u0026apos;s postpartum mood was assessed using the Edinburgh Postpartum Depression Scale (EPDS), validated for the German language [50, 51].\u003c/p\u003e\n\u003cp\u003eStatistical methods\u003c/p\u003e\n\u003cp\u003eThe statistical analysis was performed using IBM SPSS Statistics (Version 29.0.1.0, IBM Corp., Armonk, NY, USA). The Shapiro\u0026ndash;Wilk test was applied to assess the distribution of variables. In cases of non-normal distribution, results are presented as medians with interquartile ranges (IQR); for normally distributed data, means and standard deviations (SD) are reported. Categorical variables are described using absolute and percentage frequencies. Group comparisons were conducted using independent-samples t-tests (normal distribution), Mann-Whitney U tests (not normally distributed), and Fisher\u0026apos;s exact tests. Within-group changes were analyzed using paired t-tests. Statistical significance is assumed for p \u0026lt; 0.05 and is indicated by an asterisk (*).\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eParticipants and baseline characteristics\u003c/p\u003e\n\u003cp\u003eA total of 82 pregnant women were screened using the PSS-10 questionnaire. According to the established inclusion criteria, 33 participants were eligible, and data from 28 participants (14 per group) were ultimately included in the final analysis, as illustrated in Figure 2.\u003c/p\u003e\n\u003cp\u003eThere were no significant differences in maternal characteristics (reported in Table 1). The women enrolled in the study were predominantly highly educated and reported\u0026nbsp;above-average incomes. At inclusion, many participants stated that they were generally physically active and had already been in contact with yoga practices.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1. Sociodemographic, obstetric, and health parameters at baseline.\u003c/strong\u003e BMI: body mass index. ICSI: Intracytoplasmic sperm injection. IVF: in vitro fertilization. Data are presented as mean (SD), median (IQR), or n (%). *p \u0026lt; 0.05. Missing data: \u003csup\u003e1\u003c/sup\u003eone value missing.\u003c/p\u003e\n\u003ctable width=\"614\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003eYoga\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eMaternal age (years)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e35.2 (3.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e33.3 (3.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.157\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eGestational age (weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e17.3 (3.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e15.9 (3.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.284\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eBMI pregestational (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e20.8 (1.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e19.8 (19-23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.297\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eBMI at study entry (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e21.9 (2.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e21.9 (3.4)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.867\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eWorking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e10 (71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.648\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eUniversity degree\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e10 (71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e14 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.098\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eMarried\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e11 (79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.420\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eNet household income \u0026gt;5000\u0026euro;/month\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e9 (64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eEuropean ethnicity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e13 (93)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eMultiparity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e5 (36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.165\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003ePlanned pregnancy\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eIVF / ICSI / insemination\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e3 (21.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e2 (14.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eUse of psychoactive substances (tobacco, alcohol, illicit drugs)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eAutoimmune disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e2 (14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eAntidepressants\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e1 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eArterial hypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e1 (7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003eSports activity before pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e14 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e0.481\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 340px;\"\u003e\n \u003cp\u003ePrevious experience with yoga\u003c/p\u003e\n \u003cp\u003eprior to study enrollment\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e10 (71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e10 (71)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 75px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eIn the intervals of the second and third trimester screenings, overall engagement in physical activity was high in both groups, as detailed in Tables 2 and 3. The term \u0026quot;yoga study-organized\u0026quot; refers to the structured prenatal yoga sessions provided as part of the intervention for participants in the yoga group, while \u0026quot;yoga private-organized\u0026quot; encompasses any additional yoga practice pursued independently, such as attending in-person or online classes or engaging in self-guided routines at home. In the second and third trimesters, participants in the yoga group reported significantly higher levels of yoga activity, mainly due to regular participation in the study-organized sessions. They completed 13 Yoga Hatha classes (SD = 3) and 12 Yoga Nidra classes (SD = 3). The mean attendance rate was 76% (SD = 12%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Sociodemographic, obstetric, and health parameters at the second-trimester screening interval.\u003c/strong\u003e BMI: body mass index. Data presented as mean (SD), median (IQR), or n (%). *p \u0026lt; 0.05. Missing data: \u003csup\u003e1\u003c/sup\u003etwo values missing.\u003c/p\u003e\n\u003ctable width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003eYoga\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003eGestational age (weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e20.8 (1.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e19.5 (1.2)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.034*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003eCurrent BMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e22.4 (2.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e21.8 (2.7)\u003csup\u003e1\u0026nbsp;\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.549\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003eWorking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e9 (64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e9 (75)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.683\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003eSports activity (including yoga)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e7 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e12 (100)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.005*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003eYoga practice during study period\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e6 (43)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e12 (100)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.002*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003e\u0026middot;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; Yoga study-organized\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e12 (100)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e\u0026lt;0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 302px;\"\u003e\n \u003cp\u003e\u0026middot;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; Yoga private-organized\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e6 (43)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e3 (25)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 74px;\"\u003e\n \u003cp\u003e0.429\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Sociodemographic, obstetric, and health parameters at the third-trimester screening interval.\u003c/strong\u003e BMI: body mass index. Data presented as mean (SD), median (IQR), or n (%). *p \u0026lt; 0.05. No missing data.\u003c/p\u003e\n\u003ctable width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003eYoga\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eGestational age (weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e30.1 (30-31)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e29.2 (0.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e0.009*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eCurrent BMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e24.4 (2.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e23.7 (3.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e0.274\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eWorking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e9 (64)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eSports activity (including yoga)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e14 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e0.241\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eYoga practice during study period\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e14 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e0.008*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003e\u0026middot;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; Yoga study-organized\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e14 (100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e\u0026lt;0.001*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003e\u0026middot;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp; Yoga private-organized\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 110px;\"\u003e\n \u003cp\u003e2 (14)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 78px;\"\u003e\n \u003cp\u003e0.023*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;PSS-10, PDQ, and Cortisol\u003c/p\u003e\n\u003cp\u003eIn the control group, the mean PSS-10 score was 24.9 (4.8) at study entry and decreased to 17.9 (5.5) after birth, reflecting a significant reduction of 6.9 (8.1),\u0026nbsp;p\u0026nbsp;= 0.004*. The yoga group showed similar results, with an initial mean score of 24.8 (5.6) that dropped to 16.1 (4.5) post-delivery, yielding a significant difference of 8.6 (6.2),\u0026nbsp;p\u0026nbsp;\u0026lt; 0.001*. The dataset was complete across both groups.\u003c/p\u003e\n\u003cp\u003eRegarding PDQ, the control group had a mean score of 18.9 (6.9) at study entry, which declined to 15.1 (6.5) in the third trimester, a significant reduction of 3.9 (5.6),\u0026nbsp;p\u0026nbsp;= 0.012*. In the yoga group, the mean PDQ score decreased from 21.1 (7.3) at study entry to 15.4 (4.4) in the third trimester, showing a significant change of 5.7 (6.4),\u0026nbsp;p\u0026nbsp;= 0.003*. There was no missing data in either group.\u003c/p\u003e\n\u003cp\u003eWhen comparing the changes between the first and last measurements, the difference in PSS scores (\u0026Delta;PSS) was -6.9 (8.1) in the control group and -8.6 (6.2) in the yoga group, with no statistically significant difference between the groups (p\u0026nbsp;= 0.268). Similarly, for PDQ (\u0026Delta;PDQ), the control group showed a change of -3.9 (5.6) compared to -5.7 (6.4) in the yoga group, also without a significant difference between both groups (p\u0026nbsp;= 0.211).\u003c/p\u003e\n\u003cp\u003eComparing longitudinal data, a continuous reduction in stress levels from study entry (referred to as\u0026nbsp;PSS 1 or PDQ 1) until delivery (marked\u0026nbsp;PSS 4) was found (second trimester labeled as\u0026nbsp;PSS 2 or PDQ 2, third trimester indicated as PSS 3 or PDQ 3). Group differences are summarized in Tables 4 and 5 and visualized in Figures 3 and 4.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. Group comparison of the Cohen Perceived Stress Scale-10 (PSS-10) during study participation.\u003c/strong\u003e Data are presented as mean (SD), median (IQR), or n (%). *p \u0026lt; 0.05. No missing data.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 321px;\"\u003e\n \u003cp\u003ePSS-10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eYoga\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 321px;\"\u003e\n \u003cp\u003ePSS 1 value at study enrollment\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Gestational age (weeks) at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e24.9 (4.8)\u003c/p\u003e\n \u003cp\u003e16.2 (3.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e22.5 (20-28)\u003c/p\u003e\n \u003cp\u003e15.0 (3.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.828\u003c/p\u003e\n \u003cp\u003e0.360\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 321px;\"\u003e\n \u003cp\u003ePSS 2 value at second trimester screening\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;Gestational age (weeks) at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e21.1 (5.5)\u003c/p\u003e\n \u003cp\u003e20.8 (2.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e22.3 (6.5)\u003c/p\u003e\n \u003cp\u003e19.9 (1.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.311\u003c/p\u003e\n \u003cp\u003e0.160\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 321px;\"\u003e\n \u003cp\u003ePSS 3 value at third trimester screening\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Gestational age (weeks) at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e17.0 (5.5)\u003c/p\u003e\n \u003cp\u003e30.1 (0.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e16.6 (4.5)\u003c/p\u003e\n \u003cp\u003e29.2 (0.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.426\u003c/p\u003e\n \u003cp\u003e0.011*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 321px;\"\u003e\n \u003cp\u003ePSS 4 value within one week after delivery\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Days after delivery at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e17.9 (5.5)\u003c/p\u003e\n \u003cp\u003e1 (1-2.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e16.1 (4.5)\u003c/p\u003e\n \u003cp\u003e1 (0-1.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 66px;\"\u003e\n \u003cp\u003e0.177\u003c/p\u003e\n \u003cp\u003e0.170\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5. Group comparison of the Prenatal Distress Questionnaire (PDQ) during study participation.\u003c/strong\u003e Data are presented as mean (SD), median (IQR), or n (%). *p \u0026lt; 0.05. No missing data.\u0026nbsp;\u003c/p\u003e\n\u003ctable width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 331px;\"\u003e\n \u003cp\u003ePDQ\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003eYoga\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 331px;\"\u003e\n \u003cp\u003ePDQ 1 value at study enrollment\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Gestational age (weeks) at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e18.9 (6.9)\u003c/p\u003e\n \u003cp\u003e17.3 (3.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e21.0 (7.3)\u003c/p\u003e\n \u003cp\u003e15.9 (3.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.431\u003c/p\u003e\n \u003cp\u003e0.284\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 331px;\"\u003e\n \u003cp\u003ePDQ 2 value at second trimester screening\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Gestational age (weeks) at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e15.8 (7.1)\u003c/p\u003e\n \u003cp\u003e21.3 (1.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e18.3 (6.0)\u003c/p\u003e\n \u003cp\u003e20.0 (1.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.161\u003c/p\u003e\n \u003cp\u003e0.032*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 331px;\"\u003e\n \u003cp\u003ePDQ 3 value at third trimester screening\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; Gestational age (weeks) at evaluation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e15.1 (6.5)\u003c/p\u003e\n \u003cp\u003e30.1 (0.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003e15.4 (4.4)\u003c/p\u003e\n \u003cp\u003e29.2 (0.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.446\u003c/p\u003e\n \u003cp\u003e0.011*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eRegarding cortisol in hair samples (pg/mg), both groups demonstrated a significant decrease in cortisol levels from the first measurement at enrollment (\u0026ldquo;Cortisol 1\u0026rdquo;, at 17.4 (3.9) weeks of gestation) to the second measurement (\u0026ldquo;Cortisol 2\u0026rdquo;, at 1 (0-1.75) days postpartum), as illustrated in Figure 5. In-group comparison showed: at study entry, cortisol mean values of the control group measured 97.6 (56.4), and after birth, it was 35.8 (41.7), with a mean value difference of 61.8 (46.8), p = 0.005*. The yoga group started with a slightly higher cortisol level, with a cortisol mean value of 104.5 (40.6), and shows a steeper decline with a mean value of 40.0 (20.2) after birth; mean value difference 64.8 (38.3), p \u0026lt; 0.001*. For Cortisol 1, five data points were missing in the control group and one in the yoga group. The dataset was complete for Cortisol 2.\u003c/p\u003e\n\u003cp\u003eComparing between groups, the change in cortisol levels (\u0026Delta;Cortisol) between enrollment and postpartum was -61.78 (46.79) in the control group and -64.46 (38.36) in the yoga group, with no statistically significant difference (p = 0.443).\u003c/p\u003e\n\u003cp\u003ePerinatal clinical outcome\u003c/p\u003e\n\u003cp\u003eA subsequent comparison of the maternal and newborn characteristics after birth in both groups revealed no significant differences (see Table 6). Gestational age at birth, birth weight, APGAR scores, and blood gas values were similar in both groups.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe EPDS score in the control group was 7.43 (5.85) at 8.1 (6.9-8.9) weeks postpartum, compared to 7.21 (3.64) in the yoga group at 7.6 (1.8) weeks postpartum. EDPS differences were not significantly different between the two groups (p = 0.454).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6. Maternal and neonatal clinical outcomes.\u003c/strong\u003e NICU: neonatal care unit. Data are presented as mean (SD), median (IQR), or n (%). *p \u0026lt; 0.05. Missing data: \u003csup\u003e1\u003c/sup\u003eone value missing, \u003csup\u003e2\u003c/sup\u003etwo values missing, \u003csup\u003e3\u003c/sup\u003ethree values missing, \u003csup\u003e4\u003c/sup\u003efour values missing, \u003csup\u003e5\u003c/sup\u003esix values missing, \u003csup\u003e6\u003c/sup\u003enine values missing.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003ctable width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eCharacteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003eYoga\u003c/p\u003e\n \u003cp\u003en = 14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eGestational age at delivery (weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e40.0 (39-41)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e39.9 (1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.593\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eVaginal birth\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e12 (86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e7 (50)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.052\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eLabor induction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e5 (36)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e4 (29)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e1.000\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eAnalgesia during birth\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e8 (57)\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e9 (64)\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.243\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eLung maturity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eGender newborn: female\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e6 (43)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (57)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.706\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003e1min APGAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e8 (1.3)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e8 (1.9)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.436\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003e5min APGAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e9 (1.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e10 (0.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.855\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003e10min APGAR\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e10 (0.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e10 (0.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.596\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003e5min APGAR lower 7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eAdmission to NICU\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e2 (14)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.222\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eUmbilical cord pH (arterial)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e7.24 (0.05)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e7.29 (0.07)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.040*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eUmbilical cord pH (venous)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e7.35 (0.06)\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e7.37 (0.07)\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.421\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003epO2 arterial (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e20.7 (7.5)\u003csup\u003e5\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e26.0 (12.6)\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.304\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003epCO2 arterial (mmHg)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e52.9 (6.9)\u003csup\u003e5\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e44.9 (11.1)\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.090\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eGlucose arterial (mg/dl)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e92 (5)\u003csup\u003e6\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e81 (14)\u003csup\u003e5\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.130\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eBirth weight (g)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e3487 (387)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e3373 (423)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.464\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eBirth weight percentile\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e55 (22)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e40 (27)\u003csup\u003e1\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.148\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eLength newborn (cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e52 (2.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e52 (2.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.886\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 312px;\"\u003e\n \u003cp\u003eHead circumference newborn (cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 113px;\"\u003e\n \u003cp\u003e36 (1.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 104px;\"\u003e\n \u003cp\u003e34 (1.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 76px;\"\u003e\n \u003cp\u003e0.004*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003ePrincipal findings\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe data presented above indicate that both groups, those participating in the structured prenatal yoga program and those receiving standard care, experienced significant reductions in perceived stress (PSS-10), pregnancy-specific distress (PDQ), and biological stress markers (hair cortisol) throughout pregnancy. Although the yoga group consistently demonstrated slightly greater improvements, the differences between the yoga and control groups did not reach statistical significance. This suggests that while yoga may offer added benefit, other factors or coping mechanisms may have contributed to a comparable effect in the control group.\u003c/p\u003e\n\u003cp\u003eThese patterns are clearly illustrated in the visual representations of the longitudinal data. Figure 3 shows a steady decline in PSS-10 scores in both groups up to the fourth measurement point (PSS 4, after delivery). While stress levels slightly increased again in the control group at this stage, they remained low in the yoga group. However, this difference was not statistically significant. Similarly, Figures 4 and 5, which track pregnancy-specific distress and hair cortisol concentrations, reflect a continuous decrease across all evaluation points in both groups.\u003c/p\u003e\n\u003cp\u003ePotential mechanisms of yoga on the stress system\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDespite the absence of statistically significant group differences in stress reduction, pursuing the mechanisms by which yoga might promote health remains essential.\u003c/p\u003e\n\u003cp\u003eOne such pathway involves the downregulation of the HPA axis and the ANS. Although the exact physiological processes are not yet fully understood, studies suggest that regular yoga can increase vagal activity and promote parasympathetic dominance, a state associated with improved stress regulation [52, 53]. This autonomic shift may be especially beneficial during pregnancy, a period marked by extensive hormonal and emotional changes. Excessive sympathetic activation has been linked to increased risks of preterm birth, preeclampsia, and low birth weight [54]. Additionally, recent studies indicate that yoga may exert anti-inflammatory effects by reducing markers such as interleukin-6 (IL-6) and C-reactive protein (CRP), which are associated with chronic stress and potentially adverse pregnancy outcomes [55].\u003c/p\u003e\n\u003cp\u003eThe social dimension of group yoga should also be acknowledged. Participation promotes social connectedness and peer support, which are protective against psychological distress and linked to reduced perinatal anxiety and depression [56-58]. Therefore, it is plausible that some of yoga’s positive effects are also through social interactions.\u003c/p\u003e\n\u003cp\u003eExplanation for attenuated effect sizes - gestational adaptation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGiven the influence of yoga and the effects explored in this context, it is important to reflect on why, in this trial, the observed impact of yoga on stress was moderated.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWhat needs to be discussed is whether there is a natural decline in perceived stress as gestation progresses. This phenomenon may, in part, reflect psychological adaptation to pregnancy, increasing preparation for childbirth, and the availability of growing social and medical support during later stages of gestation. Supporting this, several findings show that women adjust their coping strategies throughout pregnancy, with more consistent use of planning and increasing reliance on spiritual coping, suggesting an adaptive stress management process [56, 59, 60]. This natural decline may explain the observed reductions in stress markers (PSS-10, PDQ, cortisol) in both groups. However, other findings challenge this perspective. A recent longitudinal study found that perceived stress levels, measured using the PSS-10, were significantly higher in the third trimester compared to the first and second, regardless of parity or prior miscarriage [61]. From a physiological perspective, it becomes clear that only the stress response of pregnant women is dampened, while there is a progressive increase in placental CRH, as well as ACTH and cortisol levels throughout pregnancy. The weakened response to stress can be explained by a downregulation of receptor sensitivity and increased activity of the placental enzyme 11β-hydroxysteroid dehydrogenase type 2 (11ß-HSD2), which converts cortisol into its inactive form, cortisone. This leads to a reduced transfer of cortisol into the fetal circulation [62].\u003c/p\u003e\n\u003cp\u003eMethodological considerations\u003c/p\u003e\n\u003cp\u003eThe study design and sample characteristics must be considered when interpreting the results. The participants’ characteristics were very one-sided. These were predominantly physically active, highly educated women of European background with above-average household incomes. This homogeneity may limit the generalizability of the findings. Interestingly, this sample composition contrasts with results from the FELICITy-1 study by Lobmaier et al. (2022), which found that within their subgroup of highly stressed pregnant women, participants were significantly less likely to hold a university degree or report a monthly household income above 5000€ [27]. Similar findings were reported, which also observed that pregnant women with lower socioeconomic status were more vulnerable to stress, anxiety, and depression [63]. Furthermore, due to the language-based inclusion criteria, non-German-speaking individuals were excluded from participation. This aspect also limits the sample's representativeness, particularly considering the multicultural demographic of Munich (and Germany).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eA possible confounder in assessing the effectiveness of the yoga intervention is the generally high level of physical activity reported in both the yoga and control groups. Moreover, some participants in the control group indicated that they practiced yoga independently during the study period. Although the study’s structured and supervised prenatal yoga sessions were likely more intensive and consistent, this overlap reduces the contrast between groups and may have reduced measurable group differences.\u003c/p\u003e\n\u003cp\u003eAnother critical aspect to consider is the inclusion criterion based on elevated perceived stress levels (PSS-10\u0026nbsp;≥\u0026nbsp;19), which preselected a sample already experiencing higher stress. While this approach ensured relevance to the intervention goal, it may also have introduced response bias. It is possible that some participants consciously or unconsciously exaggerated their baseline stress levels to qualify for participation in the study and gain access to the free yoga program. In turn, artificially elevated baseline scores may have contributed to the observed reduction in stress over time. Additionally, participants may have felt motivated to report improvements over time that were in line with the expected outcomes of the intervention [64, 65].\u003c/p\u003e\n\u003cp\u003eFinally, the small sample size represents a key limitation, as it restricted the statistical power and the ability to detect potential group differences. Unfortunately, organizational challenges and limited participant availability limited the number of participants who could be enrolled. In addition, recruitment constraints necessitated a quasi-randomized allocation procedure, which precluded proper randomization. This may have introduced systematic bias and limited the internal validity of the findings.\u003c/p\u003e\n\u003cp\u003eImplications and contribution\u003c/p\u003e\n\u003cp\u003eAlthough this study did not provide statistical evidence for the effectiveness of prenatal yoga in reducing stress, it contributes to the broader research landscape by applying a multimodal assessment approach in a Western population.\u003c/p\u003e\n\u003cp\u003eOne of the main strengths of this study lies in its prospective longitudinal design, which reduces recall bias by collecting data at predefined intervals throughout pregnancy [66]. Participants were observed at multiple defined time points during pregnancy. Specifically, data were gathered during the second and third trimesters, allowing for a dynamic, time-sensitive analysis of stress rather than a single-point assessment, as in FELICITy-1. This approach captures the general trends and individual fluctuations in stress levels throughout pregnancy.\u003c/p\u003e\n\u003cp\u003eAnother key advantage is the clinically-integrated yoga intervention, which was specifically designed for pregnant participants and implemented in cooperation with a certified prenatal yoga instructor. The course was adapted to pregnant women's needs and included breathing exercises, gentle stretching, and pelvic floor work. The standardized intervention helps control for confounding variables, such as variation in yoga instruction or style.\u003c/p\u003e\n\u003cp\u003eFurthermore, stress was assessed using a combination of methods, including objective measures, such as hair cortisol concentrations, and subjective data from validated self-report questionnaires. This dual perspective is essential, as stress is a complex and multidimensional construct that is difficult to capture [67]. By combining physiological and subjective data, the study offers a more nuanced understanding of perinatal stress.\u003c/p\u003e\n\u003cp\u003eFuture research\u003c/p\u003e\n\u003cp\u003eThe findings of this trial offer a solid foundation and highlight the need for further research. Future studies should include larger and more diverse cohorts to detect meaningful effects and improve generalizability. Moreover, longitudinal follow-up of offspring development is essential. As planned in our study, standardized assessments like the Parent Report of Children’s Abilities-Revised (PARCA-R), which evaluates cognitive and language development during the first two years of life, may offer valuable insights into the potential long-term benefits of prenatal yoga. Finally, integrating prenatal yoga with complementary approaches, including psychological counseling, other mindfulness techniques, or digital health applications, could enhance maternal well-being. Systematic evaluation of such multimodal interventions may lead to comprehensive support throughout pregnancy and postpartum, benefiting both mother and child.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe FELICITy-2 study suggests that maternal stress levels decline throughout pregnancy, as evidenced by significant reductions in subjective stress measures (PSS-10, PDQ) and objective biological markers (hair cortisol) across all participants. Contrary to our hypothesis, no statistically significant differences between the yoga and control groups were found. Nevertheless, yoga has the potential to be a low-risk, non-pharmacological addition to standard prenatal care. We assume that simply increasing participants’ awareness of their stress and well-being during pregnancy contributed to the overall reduction in stress levels in both groups. Moreover, the homogeneous and physically active sample, as well as independent yoga practice among the control group, may have diluted the effects of the intervention. Future studies should further clarify yoga’s role in perinatal health.\u003c/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eData Availability\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eGenerated data from the study is not available for publicity because of possible links to participants, especially newborns’ identities, but it is available from the corresponding author at a reasonable request.\u003c/p\u003e\n\u003cp\u003eAcknowledgments\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWe are thankful for all female participants of the FELICITy-2 study, whom we could accompany during the extraordinary time of their pregnancy and early motherhood. Furthermore, we are grateful for the engagement of our yoga instructor, Anne Loewer, leading the empowering yoga course for our intervention group. We want to thank everyone who contributed to the recruitment of participants, especially PD Dr. F. Stumpfe of the hospital “Dritter Orden”, Munich. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAuthors’ contributions\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCB, MCA, and SML developed the study protocol and project. Participant recruitment, data collection, and management were performed by CB, MJEM, and SML. CB, MJEM, and SML conducted statistical analyses. BF and DG performed cortisol analysis in hair samples. Manuscript writing was led by CB and SML, with editing contributions from MJEM, MF, MCA, and SML. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003eFunding\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOpen access funding was enabled and organized by the project DEAL. Partial financial support was provided by the Institute for Advanced Studies at the Technical University of Munich (Hans Fischer Senior Fellowship for MCA) and the Dr. Geisenhofer Foundation, Munich, Germany. Additional funds from the TUM University Hospital, Department of Obstetrics and Gynecology, Munich, were utilized with the authorization of SML.\u003c/p\u003e\n\u003cp\u003eAdditional Information\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe author(s) declare no competing interests.\u003c/p\u003e\n\u003cp\u003eStatement on the use of generative AI and AI-based tools\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo assist in the development of this work, the authors utilized ChatGPT (chat.openai.com) and Grammarly (grammarly.com) for minor language refinement and proofreading. All content was reviewed and revised by the authors, who assume full responsibility for the final version of the published article.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eThornburg, K. L., Jacobson, S-L., Giraud, G. D. \u0026amp; Morton, M. J. Hemodynamic changes in pregnancy. In: Seminars in perinatology. vol. 24: Elsevier; : 11\u0026ndash;14. (2000).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHytten, F. Blood volume changes in normal pregnancy. \u003cem\u003eClin. Haematol.\u003c/em\u003e \u003cb\u003e14\u003c/b\u003e (3), 601\u0026ndash;612 (1985).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEdelstein, R. S. et al. Prenatal hormones in first-time expectant parents: Longitudinal changes and within‐couple correlations. \u003cem\u003eAm. J. Hum. Biology\u003c/em\u003e. \u003cb\u003e27\u003c/b\u003e (3), 317\u0026ndash;325 (2015).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBjelica, A., Cetkovic, N., Trninic-Pjevic, A. \u0026amp; Mladenovic-Segedi, L. The phenomenon of pregnancy\u0026mdash;A psychological view. \u003cem\u003eGinekol. Pol.\u003c/em\u003e \u003cb\u003e89\u003c/b\u003e (2), 102\u0026ndash;106 (2018).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWoods, S. M., Melville, J. L., Guo, Y., Fan, M-Y. \u0026amp; Gavin, A. Psychosocial stress during pregnancy. \u003cem\u003eAm. J. Obstet. Gynecol.\u003c/em\u003e \u003cb\u003e202\u003c/b\u003e (1), 61 (2010). e1\u0026ndash;. e7.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMcEwen, B. S. Allostasis and allostatic load: implications for neuropsychopharmacology. \u003cem\u003eNeuropsychopharmacology\u003c/em\u003e \u003cb\u003e22\u003c/b\u003e (2), 108\u0026ndash;124 (2000).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJansen, A. S., Van Nguyen, X., Karpitskiy, V., Mettenleiter, T. C. \u0026amp; Loewy, A. D. Central command neurons of the sympathetic nervous system: basis of the fight-or-flight response. \u003cem\u003eScience\u003c/em\u003e \u003cb\u003e270\u003c/b\u003e (5236), 644\u0026ndash;646 (1995).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRoss, A. \u0026amp; Thomas, S. The health benefits of yoga and exercise: a review of comparison studies. \u003cem\u003eJ. Altern. Complement. Med.\u003c/em\u003e \u003cb\u003e16\u003c/b\u003e (1), 3\u0026ndash;12 (2010).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMason, J. W. A review of psychoendocrine research on the pituitary-adrenal cortical system. \u003cem\u003ePsychosom. Med.\u003c/em\u003e \u003cb\u003e30\u003c/b\u003e (5), 576\u0026ndash;607 (1968).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKirschbaum, C., Pirke, K-M. \u0026amp; Hellhammer, D. H. The \u0026lsquo;Trier Social Stress Test\u0026rsquo;\u0026ndash;a tool for investigating psychobiological stress responses in a laboratory setting. \u003cem\u003eNeuropsychobiology\u003c/em\u003e \u003cb\u003e28\u003c/b\u003e (1\u0026ndash;2), 76\u0026ndash;81 (1993).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCohen, S., Kessler, R. C. \u0026amp; Gordon, L. U. \u003cem\u003eMeasuring stress: A guide for health and social scientists\u003c/em\u003e (Oxford University Press on Demand, 1997).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBarker, D. J. The developmental origins of adult disease. \u003cem\u003eJ. Am. Coll. Nutr.\u003c/em\u003e \u003cb\u003e23\u003c/b\u003e (6 Suppl), 588s\u0026ndash;95s. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/07315724.2004.10719428\u003c/span\u003e\u003cspan address=\"10.1080/07315724.2004.10719428\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2004).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRakers, F. et al. Transfer of maternal psychosocial stress to the fetus. \u003cem\u003eNeurosci. Biobehavioral Reviews\u003c/em\u003e. \u003cb\u003e117\u003c/b\u003e, 185\u0026ndash;197 (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFowden, A. L. Endocrine regulation of fetal growth. \u003cem\u003eReprod. Fertility Dev.\u003c/em\u003e \u003cb\u003e7\u003c/b\u003e (3), 351\u0026ndash;363 (1995).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKwon, E. J. \u0026amp; Kim, Y. J. What is fetal programming? a lifetime health is under the control of in utero health. \u003cem\u003eObstet. Gynecol. Sci.\u003c/em\u003e \u003cb\u003e60\u003c/b\u003e (6), 506\u0026ndash;519 (2017).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eD\u0026Ouml;RR, H. G. et al. Longitudinal study of progestins, mineralocorticoids, and glucocorticoids throughout human pregnancy. \u003cem\u003eJ. Clin. Endocrinol. Metabolism\u003c/em\u003e. \u003cb\u003e68\u003c/b\u003e (5), 863\u0026ndash;868 (1989).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eMastorakos, G. \u0026amp; Ilias, I. Maternal and fetal hypothalamic-pituitary‐adrenal axes during pregnancy and postpartum. \u003cem\u003eAnn. N. Y. Acad. Sci.\u003c/em\u003e \u003cb\u003e997\u003c/b\u003e (1), 136\u0026ndash;149 (2003).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHuizink, A. C. Prenatal stress and its effect on infant development. (2000).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGlynn, L. M., Davis, E. P. \u0026amp; Sandman, C. A. New insights into the role of perinatal HPA-axis dysregulation in postpartum depression. \u003cem\u003eNeuropeptides\u003c/em\u003e \u003cb\u003e47\u003c/b\u003e (6), 363\u0026ndash;370 (2013).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChrousos, G. P. Stress and disorders of the stress system. \u003cem\u003eNat. reviews Endocrinol.\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e (7), 374\u0026ndash;381 (2009).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCurtis, K., Weinrib, A. \u0026amp; Katz, J. Systematic review of yoga for pregnant women: current status and future directions. Evidence-based complementary and alternative medicine. ;2012. (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGluckman, P. D., Hanson, M. A., Cooper, C. \u0026amp; Thornburg, K. L. Effect of in utero and early-life conditions on adult health and disease. \u003cem\u003eN. Engl. J. Med.\u003c/em\u003e \u003cb\u003e359\u003c/b\u003e (1), 61\u0026ndash;73 (2008).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchetter, C. D. \u0026amp; Tanner, L. Anxiety, depression and stress in pregnancy: implications for mothers, children, research, and practice. \u003cem\u003eCurr. Opin. Psychiatry\u003c/em\u003e. \u003cb\u003e25\u003c/b\u003e (2), 141\u0026ndash;148 (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eO\u0026rsquo;Donnell, K. J. \u0026amp; Meaney, M. J. Fetal origins of mental health: the developmental origins of health and disease hypothesis. \u003cem\u003eAm. J. Psychiatry\u003c/em\u003e. \u003cb\u003e174\u003c/b\u003e (4), 319\u0026ndash;328 (2017).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGitau, R., Cameron, A., Fisk, N. M. \u0026amp; Glover, V. Fetal exposure to maternal cortisol. \u003cem\u003eLancet\u003c/em\u003e \u003cb\u003e352\u003c/b\u003e (9129), 707\u0026ndash;708 (1998).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDiPietro, J. A., Costigan, K. A. \u0026amp; Gurewitsch, E. D. Fetal response to induced maternal stress. \u003cem\u003eEarly Hum. Dev.\u003c/em\u003e \u003cb\u003e74\u003c/b\u003e (2), 125\u0026ndash;138 (2003).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLobmaier, S. M. et al. Fetal heart rate variability responsiveness to maternal stress, non-invasively detected from maternal transabdominal ECG. \u003cem\u003eArch. Gynecol. Obstet.\u003c/em\u003e \u003cb\u003e301\u003c/b\u003e (2), 405\u0026ndash;414. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00404-019-05390-8\u003c/span\u003e\u003cspan address=\"10.1007/s00404-019-05390-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAntonelli, M. C. et al. Early Biomarkers and Intervention Programs for the Infant Exposed to Prenatal Stress. \u003cem\u003eCurr. Neuropharmacol.\u003c/em\u003e \u003cb\u003e20\u003c/b\u003e (1), 94\u0026ndash;106. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.2174/1570159x19666210125150955\u003c/span\u003e\u003cspan address=\"10.2174/1570159x19666210125150955\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2022).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eField, T. Yoga clinical research review. \u003cem\u003eComplement. Ther. Clin. Pract.\u003c/em\u003e \u003cb\u003e17\u003c/b\u003e (1), 1\u0026ndash;8 (2011).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBabbar, S. \u0026amp; Shyken, J. Yoga in pregnancy. \u003cem\u003eClin. Obstet. Gynecol.\u003c/em\u003e \u003cb\u003e59\u003c/b\u003e (3), 600\u0026ndash;612 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eField, T. et al. Yoga and massage therapy reduce prenatal depression and prematurity. \u003cem\u003eJ. Bodyw. Mov. Ther.\u003c/em\u003e \u003cb\u003e16\u003c/b\u003e (2), 204\u0026ndash;209 (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDeshpande, C. et al. Yoga for High\u0026ndash;Risk Pregnancy: A Randomized Controlled Trial. \u003cem\u003eAnnals Med. health Sci. Res.\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e (3), 341\u0026ndash;344 (2013).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNewham, J. J., Wittkowski, A., Hurley, J., Aplin, J. D. \u0026amp; Westwood, M. Effects of antenatal yoga on maternal anxiety and depression: a randomized controlled trial. \u003cem\u003eDepress. Anxiety\u003c/em\u003e. \u003cb\u003e31\u003c/b\u003e (8), 631\u0026ndash;640 (2014).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKwon, R., Kasper, K., London, S. \u0026amp; Haas, D. M. A systematic review: The effects of yoga on pregnancy. \u003cem\u003eEur. J. Obstet. Gynecol. Reproductive Biology\u003c/em\u003e. \u003cb\u003e250\u003c/b\u003e, 171\u0026ndash;177 (2020).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCorrigan, L., Moran, P., McGrath, N., Eustace-Cook, J. \u0026amp; Daly, D. The characteristics and effectiveness of pregnancy yoga interventions: a systematic review and meta-analysis. \u003cem\u003eBMC pregnancy childbirth\u003c/em\u003e. \u003cb\u003e22\u003c/b\u003e (1), 250 (2022).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGordijn, S. J. et al. Consensus definition of fetal growth restriction: a Delphi procedure. \u003cem\u003eUltrasound Obstet. Gynecol.\u003c/em\u003e \u003cb\u003e48\u003c/b\u003e (3), 333\u0026ndash;339. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/uog.15884\u003c/span\u003e\u003cspan address=\"10.1002/uog.15884\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKilpatrick, S. K. \u0026amp; Ecker, J. L. Severe maternal morbidity: screening and review. \u003cem\u003eAm. J. Obstet. Gynecol.\u003c/em\u003e \u003cb\u003e215\u003c/b\u003e (3), B17\u0026ndash;22. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.ajog.2016.07.050\u003c/span\u003e\u003cspan address=\"10.1016/j.ajog.2016.07.050\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIyengar, B. K., Menuhin, Y. \u0026amp; Mangoldt, U. Licht auf Yoga: Yoga-Dīpikā: das grundlegende Lehrbuch des Hatha-Yoga. (No Title). (1993).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eQuinker, D. Einfluss von \u0026Uuml;bungsh\u0026auml;ufigkeit und Yogastil auf die Gesundheit, den Lebensstil und die Sicherheit von Yoga\u0026uuml;benden: eine Onlineumfrage. In.: Dissertation, Duisburg, Essen, Universit\u0026auml;t Duisburg-Essen, ; 2021. (2021).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePandi-Perumal, S. R. et al. The origin and clinical relevance of yoga nidra. \u003cem\u003eSleep. Vigilance\u003c/em\u003e. \u003cb\u003e6\u003c/b\u003e (1), 61\u0026ndash;84 (2022).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSaraswati, S. S. \u0026amp; Hiti, J. K. \u003cem\u003eYoga nidra\u003c/em\u003e (Bihar School of Yoga Munger, 1984).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCohen, S., Kamarck, T. \u0026amp; Mermelstein, R. A global measure of perceived stress. \u003cem\u003eJ. Health Soc. Behav.\u003c/em\u003e \u003cb\u003e24\u003c/b\u003e (4), 385\u0026ndash;396 (1983).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYali, A. M. \u0026amp; Lobel, M. Coping and distress in pregnancy: an investigation of medically high risk women. \u003cem\u003eJ. Psychosom. Obstet. Gynaecol.\u003c/em\u003e \u003cb\u003e20\u003c/b\u003e (1), 39\u0026ndash;52. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3109/01674829909075575\u003c/span\u003e\u003cspan address=\"10.3109/01674829909075575\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (1999).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKlein, E. M. et al. The German version of the Perceived Stress Scale\u0026ndash;psychometric characteristics in a representative German community sample. \u003cem\u003eBMC psychiatry\u003c/em\u003e. \u003cb\u003e16\u003c/b\u003e, 1\u0026ndash;10 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePluess, M., Bolten, M., Pirke, K-M. \u0026amp; Hellhammer, D. Maternal trait anxiety, emotional distress, and salivary cortisol in pregnancy. \u003cem\u003eBiol. Psychol.\u003c/em\u003e \u003cb\u003e83\u003c/b\u003e (3), 169\u0026ndash;175 (2010).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCooper, G. A., Kronstrand, R. \u0026amp; Kintz, P. Society of Hair Testing guidelines for drug testing in hair. \u003cem\u003eForensic Sci. Int.\u003c/em\u003e \u003cb\u003e218\u003c/b\u003e (1\u0026ndash;3), 20\u0026ndash;24 (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKarl\u0026eacute;n, J., Ludvigsson, J., Frostell, A., Theodorsson, E. \u0026amp; Faresj\u0026ouml;, T. Cortisol in hair measured in young adults-a biomarker of major life stressors? \u003cem\u003eBMC Clin. Pathol.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e, 1\u0026ndash;6 (2011).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIglesias, S. et al. Hair cortisol: A new tool for evaluating stress in programs of stress management. \u003cem\u003eLife Sci.\u003c/em\u003e \u003cb\u003e141\u003c/b\u003e, 188\u0026ndash;192. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.lfs.2015.10.006\u003c/span\u003e\u003cspan address=\"10.1016/j.lfs.2015.10.006\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2015).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGonzalez, D. et al. Hair cortisol measurement by an automated method. \u003cem\u003eSci. Rep.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e (1), 8213 (2019).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCox, J. \u0026amp; Holden, J. \u003cem\u003ePerinatal mental health: A guide to the Edinburgh Postnatal Depression Scale (EPDS)\u003c/em\u003e (Royal College of Psychiatrists, 2003).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBergant, A., Nguyen, T., Heim, K., Ulmer, H. \u0026amp; Dapunt, O. German language version and validation of the Edinburgh postnatal depression scale. Deutsche medizinische Wochenschrift 1998;123(3):35\u0026ndash;40. (1946).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHayase, M. \u0026amp; Shimada, M. Effects of maternity yoga on the autonomic nervous system during pregnancy. \u003cem\u003eJ. Obstet. Gynaecol. Res.\u003c/em\u003e \u003cb\u003e44\u003c/b\u003e (10), 1887\u0026ndash;1895. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/jog.13729\u003c/span\u003e\u003cspan address=\"10.1111/jog.13729\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2018).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eStreeter, C. C., Gerbarg, P. L., Saper, R. B., Ciraulo, D. A. \u0026amp; Brown, R. P. Effects of yoga on the autonomic nervous system, gamma-aminobutyric-acid, and allostasis in epilepsy, depression, and post-traumatic stress disorder. \u003cem\u003eMed. Hypotheses\u003c/em\u003e. \u003cb\u003e78\u003c/b\u003e (5), 571\u0026ndash;579 (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChristian, L. M. Physiological reactivity to psychological stress in human pregnancy: current knowledge and future directions. \u003cem\u003eProg. Neurobiol.\u003c/em\u003e \u003cb\u003e99\u003c/b\u003e (2), 106\u0026ndash;116 (2012).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKiecolt-Glaser, J. K. et al. Stress, inflammation, and yoga practice. \u003cem\u003eBiopsychosoc. Sci. Med.\u003c/em\u003e \u003cb\u003e72\u003c/b\u003e (2), 113\u0026ndash;121 (2010).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYali, A. M. \u0026amp; Lobel, M. Stress-resistance resources and coping in pregnancy. \u003cem\u003eAnxiety Stress Coping\u003c/em\u003e. \u003cb\u003e15\u003c/b\u003e (3), 289\u0026ndash;309 (2002).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRazurel, C. \u0026amp; Kaiser, B. The role of satisfaction with social support on the psychological health of primiparous mothers in the perinatal period. \u003cem\u003eWomen health\u003c/em\u003e. \u003cb\u003e55\u003c/b\u003e (2), 167\u0026ndash;186 (2015).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCollins, N. L., Dunkel-Schetter, C., Lobel, M. \u0026amp; Scrimshaw, S. C. Social support in pregnancy: psychosocial correlates of birth outcomes and postpartum depression. \u003cem\u003eJ. Personal. Soc. Psychol.\u003c/em\u003e \u003cb\u003e65\u003c/b\u003e (6), 1243 (1993).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHamilton, J. G. \u0026amp; Lobel, M. Types, patterns, and predictors of coping with stress during pregnancy: Examination of the Revised Prenatal Coping Inventory in a diverse sample. \u003cem\u003eJ. Psychosom. Obstet. Gynecol.\u003c/em\u003e \u003cb\u003e29\u003c/b\u003e (2), 97\u0026ndash;104 (2008).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDunkel Schetter, C. Psychological science on pregnancy: stress processes, biopsychosocial models, and emerging research issues. \u003cem\u003eAnn. Rev. Psychol.\u003c/em\u003e \u003cb\u003e62\u003c/b\u003e (1), 531\u0026ndash;558 (2011).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eRedondo, M. M., Liebana-Presa, C., P\u0026eacute;rez-Rivera, J., Mart\u0026iacute;n-V\u0026aacute;zquez, C. \u0026amp; Calvo-Ayuso, N. Garc\u0026iacute;a-Fern\u0026aacute;ndez R. Exploring Self-Perceived Stress and Anxiety Throughout Pregnancy: A Longitudinal Study. \u003cem\u003eDiseases\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e (4), 121 (2025).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eEntringer, S. et al. Attenuation of maternal psychophysiological stress responses and the maternal cortisol awakening response over the course of human pregnancy. \u003cem\u003eStress\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e (3), 258\u0026ndash;268 (2010).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eNagandla, K. et al. Prevalence and associated risk factors of depression, anxiety and stress in pregnancy. \u003cem\u003eInt. J. Reprod. Contracept. Obstet. Gynecol.\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e (7), 2380\u0026ndash;2389 (2016).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePodsakoff, P. M., MacKenzie, S. B., Lee, J-Y. \u0026amp; Podsakoff, N. P. Common method biases in behavioral research: a critical review of the literature and recommended remedies. \u003cem\u003eJ. Appl. Psychol.\u003c/em\u003e \u003cb\u003e88\u003c/b\u003e (5), 879 (2003).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eOrne, M. T. On the social psychology of the psychological experiment: With particular reference to demand characteristics and their implications. In: Sociological methods. Routledge; 279\u0026ndash;299. (2017).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHassan, E. Recall bias can be a threat to retrospective and prospective research designs. \u003cem\u003eInternet J. Epidemiol.\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e (2), 339\u0026ndash;412 (2006).\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKopp, M. S. et al. Measures of stress in epidemiological research. \u003cem\u003eJ. Psychosom. Res.\u003c/em\u003e \u003cb\u003e69\u003c/b\u003e (2), 211\u0026ndash;225 (2010).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Yoga intervention, Pregnancy, Prenatal stress, Perceived Stress Scale-10, Cortisol","lastPublishedDoi":"10.21203/rs.3.rs-7366549/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7366549/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eProlonged maternal stress during pregnancy can adversely affect offspring development. This study evaluated the efficacy of an integrative prenatal yoga program, combining Yoga Hatha and Yoga Nidra, in reducing maternal stress levels during pregnancy and childbirth. A prospective quasi-randomized controlled trial was conducted at the TUM University Hospital, Munich, from December 2022 to June 2024. Pregnant women between 12\u0026thinsp;+\u0026thinsp;0 and 20\u0026thinsp;+\u0026thinsp;0 weeks of gestation with elevated stress levels (Perceived Stress Scale-10 (PSS-10)\u0026thinsp;\u0026ge;\u0026thinsp;19) were eligible. 28 participants were included in the final analysis, with 14 assigned to a yoga intervention group and 14 to a control group receiving standard prenatal care. Stress was assessed via PSS-10, the Prenatal Distress Questionnaire (PDQ), and hair cortisol concentrations at baseline, during pregnancy, and postpartum. Both groups showed significant declines in PSS-10, PDQ, and cortisol over time. Improvements were slightly greater in the yoga group, but differences were not statistically significant. By integrating subjective and objective measures, this study provided insights into stress patterns during pregnancy. While the structured yoga program did not produce significant group differences, it may represent a meaningful and practical approach to prenatal stress reduction. Larger, more diverse studies are warranted. Registry: German Clinical Trials Register (DRKS), TRN: DRKS00037529, Registration date: 24 July 2025.\u003c/p\u003e","manuscriptTitle":"Prenatal yoga for stress reduction: results from the FELICITy-2 quasi-randomized controlled trial","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-08 07:48:35","doi":"10.21203/rs.3.rs-7366549/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-03-31T12:14:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"279392059860717150032741419828946774575","date":"2026-03-16T15:07:40+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-12-03T10:48:39+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-09-09T15:17:35+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-19T03:54:05+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-18T02:52:06+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-08-13T15:34:15+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0a3ec363-670d-4d3b-ae4c-ce471090175b","owner":[],"postedDate":"December 8th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":59031865,"name":"Health sciences/Health care"},{"id":59031866,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2025-12-08T07:48:35+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-08 07:48:35","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7366549","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7366549","identity":"rs-7366549","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}