Maternal Ramadan Fasting and Fetal Cardiac Function: Subclinical Hemodynamic Alterations Revealed by Doppler Evaluation

Maternal Ramadan Fasting and Fetal Cardiac Function: Subclinical Hemodynamic Alterations Revealed by Doppler Evaluation | 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 Research Article Maternal Ramadan Fasting and Fetal Cardiac Function: Subclinical Hemodynamic Alterations Revealed by Doppler Evaluation Deniz Taşdemir This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7908308/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 05 Feb, 2026 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted 4 You are reading this latest preprint version Abstract Backround and Objectives: To evaluate the impact of maternal Ramadan fasting on fetal cardiac function and hemodynamics using comprehensive Doppler echocardiography, emphasizing subclinical myocardial and circulatory adaptations. Materials and Methods: In this prospective study, 203 healthy singleton pregnancies between 24 and 32 weeks of gestation were examined—102 women who fasted for ≥ 10 days during Ramadan and 101 non-fasting controls. The study was prospectively registered with the National Clinical Trial (NCT06900257, registration date 23 March 2025). Doppler assessments included umbilical, middle cerebral, and ductus venosus pulsatility indices (PI), cerebroplacental ratio, and cardiac parameters: left and right myocardial performance indices (LV MPI, RV MPI), tricuspid and mitral annular plane systolic excursions (TAPSE, MAPSE), cardiothoracic ratio (CTR), and amniotic fluid index (AFI). Statistical analyses were performed using IBM SPSS v25.0 and Python 3.10, including correlation, regression, and ROC analysis. Results: Fasting pregnancies demonstrated significantly higher MCA PI (p < 0.001), LV MPI (p < 0.001), RV MPI (p = 0.041), and CTR (p < 0.001), and lower AFI (p < 0.001) than controls. Umbilical and ductus venosus PI, TAPSE, and MAPSE did not differ significantly. LV MPI correlated positively with CTR (r = 0.33) and inversely with AFI (r = − 0.42). Fasting independently predicted increased LV MPI and decreased AFI. ROC analysis showed limited predictive power of MPI for low AFI (AUC = 0.52). Conclusions: Maternal Ramadan fasting induces mild, reversible fetal cardiovascular adaptations—characterized by increased MPI and MCA PI and reduced AFI—without evidence of fetal distress. These findings emphasize fetal hemodynamic resilience but support individualized monitoring during fasting in pregnancy. Ramadan fasting pregnancy fetal cardiac function myocardial performance index (MPI) Doppler ultrasonography amniotic fluid index (AFI) Figures Figure 1 Introduction Ramadan fasting, observed by millions of Muslims worldwide, entails abstaining from food and fluids from dawn to sunset. Although pregnant women are religiously exempt, many continue fasting for cultural and personal reasons [ 1 – 3 ]. Pregnancy, however, is a state of increased metabolic demand and fluid requirement, making prolonged fasting a potential physiological stressor that may influence fetal well-being [ 4 ]. Previous studies have examined the effects of Ramadan fasting on maternal metabolism, fetal growth, and amniotic fluid volume, with largely inconsistent results [ 5 – 7 ]. While most report no adverse perinatal outcomes, subtle metabolic shifts such as reduced glucose and hydration levels could theoretically affect fetal circulation and cardiac function [ 8 ]. Fetal cardiac performance can be objectively assessed by Doppler-derived indices including the myocardial performance index (MPI) , tricuspid and mitral annular plane systolic excursions (TAPSE, MAPSE) , and cerebral–umbilical resistance ratios [ 9 – 11 ]. These parameters reflect early subclinical hemodynamic changes even in the absence of overt fetal distress. Yet, the impact of maternal fasting on these sensitive cardiovascular markers remains poorly understood. Therefore, this study aimed to evaluate the effects of maternal Ramadan fasting on fetal cardiac function and hemodynamics using detailed Doppler assessment. We hypothesized that fasting during pregnancy may induce subclinical alterations in fetal myocardial performance and circulatory dynamics detectable by ultrasound evaluation. Material and Methods This study was conducted between January 2025 and July 2025 at the Perinatology Outpatient Clinic of Şanlıurfa Training and Research Hospital , following approval by the Institutional Ethics Committee (Approval No: HRÜ/25.03.01]). This prospective observational study was registered with the National Clinical Trial (NCT06900257, registration date 23 March 2025 ) prior to participant enrollment to ensure transparency and adherence to international research standards. All participants provided written informed consent prior to enrollment, and the study was performed in accordance with the Declaration of Helsinki principles. Study Population A total of 203 healthy pregnant women between 24 and 32 weeks of gestation were enrolled and stratified into two groups: Fasting group (n = 102): women who observed Ramadan fasting for ≥10 consecutive days, verified by self-report and fasting logs. Control group (n = 101): women who did not fast during the same period and were matched for maternal age (±2 years), gravidity, and gestational week (±1 week). Inclusion criteria were: singleton pregnancy, absence of structural or chromosomal fetal anomalies, normal first- and second-trimester screening, and regular antenatal follow-up. Exclusion criteria included pre-existing diabetes mellitus, hypertension, thyroid or renal disease, polyhydramnios/oligohydramnios, intrauterine growth restriction, smoking, and use of medications affecting cardiovascular or metabolic status. Maternal demographic and obstetric data were recorded, including age, parity, pre-pregnancy BMI, gestational week, and number of fasting days. Ultrasound and Doppler Protocol All sonographic assessments were performed by a single maternal–fetal medicine specialist with >10 years of experience, using a GE Voluson E8 Expert ® system equipped with a 2–9 MHz convex transducer (C2-9-D) . To minimize metabolic variability, examinations in the fasting group were scheduled within the last two hours of the fasting period (typically between 5:00–7:00 PM). Fetal biometric measurements (BPD, FL, AC, EFW) were recorded, followed by Doppler evaluations performed under controlled conditions: Insonation angle: <30°, optimized for each vessel Fetal activity: absent or minimal movement Sweep speed: 5 cm/s Wall motion filter: 300 Hz Sample volume: 3–4 mm For each vessel, at least six consecutive uniform waveforms were obtained and averaged. Vascular Doppler Parameters Umbilical artery (UA): sampled from a free-floating cord segment. Middle cerebral artery (MCA): measured at the proximal third near its origin from the circle of Willis. Ductus venosus (DV): visualized in the midsagittal plane, confirming triphasic waveform morphology. The pulsatility index (PI) was calculated for each vessel. The MCA/UA PI ratio served as an index of cerebroplacental resistance, where lower values suggest fetal circulatory redistribution. Cardiac Functional Assessment Fetal cardiac function was analyzed using both spectral Doppler and M-mode echocardiography: Mitral and tricuspid inflow (E and A waves) measured from apical four-chamber view to calculate E/A ratios. The fetal MPI was calculated as (IVCT + IVRT) / ET, where IVCT is the isovolumetric contraction time, IVRT the isovolumetric relaxation time, and ET the ejection time [11]. TAPSE and MAPSE were obtained via M-mode along the lateral annulus of the tricuspid and mitral valves, reflecting longitudinal systolic motion. CTR and Ventricular Sphericity Indices (LVSI, RVSI) were calculated to assess cardiac geometry and remodeling. Amniotic Fluid Index (AFI) was determined by the four-quadrant method and recorded in centimeters. All measurements were averaged from three consecutive cardiac cycles to minimize intraobserver variability. Interobserver reproducibility was not tested due to single-operator design but intraobserver variability was maintained below 5%. Statistical Analysis All data were analyzed using IBM SPSS Statistics version 25.0 (IBM Corp., Armonk, NY, USA) and cross-validated with Python 3.10 (Pandas, Statsmodels, SciPy) for advanced statistical analyses.Continuous variables were expressed as mean ± SD and 95% confidence intervals (CI) . The Kolmogorov–Smirnov test was used to assess data normality. For group comparisons: Independent Samples t-test was applied for normally distributed data. Mann–Whitney U test for non-parametric data. Categorical variables were analyzed with the Chi-square test . Statistical significance was set at p < 0.05. To strengthen analytical robustness beyond mean comparison, multiple complementary analyses were incorporated: Effect Size (Cohen’s d ): Quantified the magnitude of intergroup differences for major parameters (MCA PI, LV MPI, RV MPI, CTR, AFI). Effect sizes were interpreted as small (0.2), medium (0.5), or large (≥0.8). Correlation Analysis: Spearman’s rank correlation (rₛ) was employed to explore relationships among fetal cardiac and hemodynamic parameters (LV MPI, RV MPI, CTR, AFI, MCA PI). Correlations were categorized as weak (r 0.5). Multiple Linear Regression: Separate regression models were built for LV MPI and AFI as dependent variables. Independent predictors included fasting status (binary), gestational age (weeks), and fetal heart rate. Model adequacy was tested using R² , adjusted R² , β coefficients , and 95% CI . Multicollinearity was excluded with variance inflation factor (VIF < 2.0) . Receiver Operating Characteristic (ROC) Analysis: The discriminative capacity of LV MPI in identifying low amniotic fluid (AFI 0.8 excellent. The optimal cut-off was derived using Youden’s Index (J = Sensitivity + Specificity – 1) . Power and Sensitivity Analysis: Post hoc power calculations demonstrated an achieved statistical power of >0.85 for significant comparisons (LV MPI, CTR, AFI), confirming adequate sample size. Results A total of 203 singleton pregnancies were included in the final analysis, comprising 102 fasting and 101 control participants. The mean gestational age at assessment was similar between groups (27.1 ± 2.6 vs. 26.3 ± 2.1 weeks, p = 0.056), whereas the mean fasting duration among fasting women was 21.7 ± 4.0 days (Table 1). Fetal Doppler Hemodynamics Umbilical artery and ductus venosus pulsatility indices (PI) were comparable between fasting and control groups ( p > 0.05). However, the middle cerebral artery PI was significantly higher in fasting pregnancies (2.13 ± 0.17 vs. 2.05 ± 0.14, p < 0.001), indicating increased cerebral vascular resistance. Similarly, the MCA/UA PI ratio was significantly elevated in the fasting group (2.12 ± 0.35 vs. 2.01 ± 0.25, p = 0.010) (Table 2). Fetal Cardiac Function and Morphology No significant differences were found in mitral or tricuspid E/A ratios, TAPSE, or MAPSE values between groups ( p > 0.05). In contrast, both left and right ventricular myocardial performance indices (LV MPI and RV MPI) were significantly higher among fasting women (0.54 ± 0.08 vs. 0.49 ± 0.08, p < 0.001; 0.56 ± 0.09 vs. 0.53 ± 0.10, p = 0.041, respectively), suggesting mild subclinical cardiac loading. Cardiothoracic ratio (CTR) was notably increased in the fasting group (0.29 ± 0.02 vs. 0.23 ± 0.04, p < 0.001), while amniotic fluid index (AFI) was markedly lower (11.24 ± 1.41 vs. 17.92 ± 1.60 cm, p < 0.001) (Table 3). Effect Size and Clinical Significance Cohen’s d analysis demonstrated clinically meaningful differences for several parameters (Table 4). The largest effect was observed for AFI ( d = 1.35, very large), followed by CTR ( d = 0.82, large) and LV MPI ( d = 0.63, moderate–large). These findings support the presence of physiologic alterations in both fetal cardiac performance and fluid balance during maternal fasting. Correlation Analysis Spearman’s correlation matrix revealed significant associations between cardiac and hemodynamic variables (Table 5). LV MPI correlated positively with RV MPI ( r = 0.52, p < 0.001) and CTR ( r = 0.33, p < 0.05), but negatively with AFI ( r = –0.42, p < 0.001). Similarly, MCA PI was inversely associated with AFI ( r = –0.36, p < 0.05). These results suggest that increased fetal cardiac load and cerebral vascular resistance are accompanied by reduced amniotic fluid volume, reflecting a potential systemic adaptation to maternal fasting. Regression Analysis Multiple linear regression models identified fasting as an independent predictor of elevated LV MPI and reduced AFI after adjustment for gestational age (Table 6). Fasting status was significantly associated with higher LV MPI (β = 0.036, p = 0.002) and lower AFI (β = –6.648, p < 0.001). Gestational age showed a modest positive association with LV MPI (β = 0.0078, p = 0.001) but had no significant effect on AFI ( p = 0.291). The models explained 11% and 83% of the variance in LV MPI and AFI, respectively. ROC Curve Analysis Receiver operating characteristic (ROC) analysis was performed to evaluate the ability of LV MPI to predict low amniotic fluid volume (AFI < 10 cm). The area under the curve (AUC) was 0.52 (95% CI: 0.46–0.58), indicating limited discriminative power of LV MPI in detecting pregnancies with reduced AFI (Table 7, Figure 1). Although the predictive accuracy was modest, the observed relationship between higher MPI and lower AFI suggests underlying hemodynamic stress that may not yet manifest as overt fetal compromise. Discussion This prospective study explored the hemodynamic and myocardial responses of fetuses to maternal Ramadan fasting using comprehensive Doppler echocardiography. The results demonstrated significantly higher MCA PI , left and right ventricular myocardial performance indices (LV MPI, RV MPI) , and CTR in fasting pregnancies, while the AFI was notably reduced. Conversely, umbilical and ductus venosus (DV) Doppler indices , as well as TAPSE , MAPSE , and heart rate, remained unchanged. These findings suggest that maternal fasting induces subclinical, adaptive cardiovascular responses in the fetus rather than pathological compromise. Fetal Cerebral Hemodynamics The increase in MCA PI observed in fasting pregnancies implies a mild rise in cerebrovascular resistance. Previous research has reported inconsistent effects of fasting on cerebral blood flow [5,6]. While some authors found no significant differences in MCA or umbilical indices [5,7], our results align with the physiological hypothesis that maternal hypoglycemia and dehydration toward the end of the fasting day may transiently increase cerebrovascular impedance [12,13]. Cerebral autoregulation allows the fetus to maintain oxygen delivery despite short-term metabolic fluctuations [14]. Thus, elevated MCA PI in our cohort likely reflects reversible metabolic vasoreactivity rather than hypoxic redistribution. This adaptive response may differ depending on the duration of fasting, gestational age, and climatic conditions, particularly during longer summer fasts [4]. Fetal Myocardial Performance The increase in LV and RV MPI among fasting women represents the most notable and novel finding of this study. MPI integrates both systolic and diastolic performance by combining isovolumetric contraction and relaxation times relative to ejection time [11]. Previous studies have shown that elevated MPI is an early sign of ventricular loading alteration in conditions such as intrauterine growth restriction and gestational diabetes [9,10,15]. The observed MPI elevation in fasting pregnancies, independent of gestational age, may result from subtle reductions in preload or changes in myocardial relaxation secondary to transient maternal dehydration and reduced glucose supply [12,16]. Importantly, TAPSE and MAPSE values remained stable, indicating preserved systolic contractility and supporting the concept of diastolic sensitivity to metabolic shifts as the earliest detectable myocardial response [9]. Cardiac Morphology and Circulatory Load An increased cardiothoracic ratio (CTR) was also observed among fasting women. Although CTR has been associated with pathological cardiomegaly in fetal compromise [17], modest increases in CTR without changes in sphericity indices (LVSI, RVSI) likely indicate temporary volume adaptation or mild preload elevation. Comparable findings have been reported in adaptive fetal remodeling under mild hemodynamic stress [18,19]. The absence of structural deformation or venous congestion in our study supports that these cardiac modifications are functional and reversible rather than pathologic. Amniotic Fluid and Placental Perfusion The reduction in AFI observed among fasting women is consistent with several previous studies [20,21], which attributed the decrease primarily to maternal dehydration and reduced renal plasma flow . However, other investigations did not find significant AFI changes [5,7], likely due to differences in fasting duration, environmental conditions, and fluid intake habits [4,22]. In our cohort, conducted in southeastern Türkiye during long fasting hours, lower AFI likely reflects maternal water restriction rather than placental dysfunction. The negative correlation between AFI and MPI further suggests an interrelated compensatory mechanism : as placental flow and amniotic fluid decrease, fetal myocardial workload subtly increases to maintain adequate circulation [9,10]. Integrative Physiological Interpretation Collectively, the combination of increased MPI, elevated MCA PI, and reduced AFI represents a coordinated, subclinical fetal response to transient maternal metabolic and hydration changes. This adaptive pattern supports the concept of fetal cardiovascular resilience , wherein the fetus maintains hemodynamic homeostasis through autonomic and myocardial adjustments [11,14]. Such physiological buffering likely explains why large population studies found no adverse effects of Ramadan fasting on birth weight or neonatal outcomes [8,23]. Nevertheless, this adaptive reserve may be limited in pregnancies with compromised placental function, such as preeclampsia or fetal growth restriction [24-26]. Clinical Implications Our results reinforce that Ramadan fasting is generally safe in healthy pregnancies , provided that hydration and caloric intake are adequate [1,2]. However, the observed Doppler-based changes highlight the need for individualized counseling and monitoring . Clinicians should recommend adequate fluid intake during non-fasting hours, shorter fasting durations when possible, and mid-Ramadan fetal Doppler assessment for women at increased risk. In cases with pre-existing maternal or placental compromise, temporary fasting exemptions should be considered to prevent potential fetal stress [5,6]. Strengths and Limitations The strengths of this study include its prospective design , homogeneous cohort , and comprehensive cardiac assessment using multiple Doppler-derived indices. Advanced statistical modeling—such as effect size analysis, multivariable regression, and ROC curve evaluation —enhanced interpretative depth. However, this was a single-center study , and maternal biochemical markers (e.g., glucose, insulin, ketone bodies) were not measured concurrently. Additionally, long-term neonatal outcomes were not evaluated, and thus the persistence of these subclinical cardiac adaptations remains uncertain. Finally, seasonal and geographic variability may influence fasting effects, necessitating multicenter replication under different environmental conditions. Future Directions Future studies should integrate maternal metabolic profiling, serial fetal Doppler monitoring, and postnatal echocardiography to delineate the temporal dynamics of these adaptations. Emerging technologies, including fetal strain imaging , 3D cardiac volumetry , and AI-based Doppler waveform analysis , may provide greater insight into subtle myocardial and vascular changes. Expanding research to include high-risk pregnancies will be critical to identify thresholds where fasting transitions from adaptive to detrimental. Conclusion In conclusion, maternal Ramadan fasting appears to induce transient and reversible fetal cardiovascular adjustments , characterized by increased MPI and MCA PI and reduced AFI, without overt signs of fetal distress. These findings highlight the adaptive capacity of the fetal cardiovascular system and support the safety of fasting among healthy women under proper nutritional and medical supervision. Nonetheless, careful individualized assessment remains essential, and further longitudinal studies are needed to clarify the long-term significance of these subtle hemodynamic changes. Declarations Ethical Approval This study was conducted in compliance with the ethical principles outlined in the Declaration of Helsinki. Ethical approval was obtained from the Harran University Ethics Committee under approval number HRÜ/25.03.01. This prospective observational study was registered with the National Clinical Trial (NCT06900257) prior to participant enrollment to ensure transparency and adherence to international research standards. Written informed consent was obtained from all participants prior to their inclusion in the study. Participants had the right to withdraw from the study at any time without consequences. All collected data were anonymized and stored securely to maintain confidentiality. Consent to Participate Following ethics committee approval, written informed consent forms were obtained from all participants for their participation in the study. Consent for Publication This study does not include any identifying information, and all data were anonymized to ensure participant confidentiality. There are no restrictions or concerns regarding the publication of this study. Availability of Data and Materials Patient data used in this study are securely stored in the hospital's automation system and are available upon reasonable request, provided that participant confidentiality is maintained. Competing Interests The authors declare no competing interests. Authors' Contributions Deniz Taşdemir was solely responsible for the conception and design of the study, data collection, ultrasonographic examinations, statistical analysis, interpretation of results, and manuscript drafting and revision. The author approved the final version of the manuscript and agrees to be accountable for all aspects of the work. Funding No financial support was received for this study. Acknowledgments The authors would like to thank the medical staff and patients at Perinatology Outpatient Clinic of Şanlıurfa Training and Research Hospital for their valuable contributions to this research. References Azizi F. Islamic fasting and health. Ann Nutr Metab. 2010;56(4):273–282. 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Umbilical and middle cerebral artery Doppler indices in patients with preeclampsia. Eur J Obstet Gynecol Reprod Biol. 1999;82(1):11–16. Makhseed M, Jirous J, Ahmed MA, Viswanathan DL. Middle cerebral artery to umbilical artery resistance index ratio in the prediction of neonatal outcome. Int J Gynecol Obstet. 2000;71(2):119–125. Tables Table 1. Comparison of Gestational Age and Fasting Duration Between Fasting and Control Groups Parameter Fasting Group (n = 102) Control Group (n = 101) p value Gestational age (weeks) 27.1 ± 2.6 (24–34) [95% CI: 26.6–27.7] 26.3 ± 2.1 (24–31.5) [95% CI: 25.9–26.8] 0.056ᵇ Fasting duration (days) 21.7 ± 4.0 (13–29) [95% CI: 20.9–22.5] — — Note. Continuous variables are presented as mean ± standard deviation (range) and 95% confidence interval (CI). ᵇ Mann–Whitney U test was used for non-normally distributed data. Abbreviations: CI = Confidence Interval. Table 2. Comparison of Fetal Doppler Pulsatility Index (PI) Parameters Between Fasting and Control Groups Parameter Fasting Group (n = 102) Control Group (n = 101) p value Umbilical artery PI 1.02 ± 0.16 (0.65–1.36) [95% CI: 0.99–1.06] 1.03 ± 0.15 (0.74–1.35) [95% CI: 1.03–1.06] 0.890ᵇ Middle cerebral artery (MCA) PI 2.13 ± 0.17 (1.82–2.64) [95% CI: 2.10–2.17] 2.05 ± 0.14 (1.79–2.45) [95% CI: 2.02–2.07] <0.001ᶜ Ductus venosus (DV) PI 0.77 ± 0.15 (0.41–1.34) [95% CI: 0.74–0.80] 0.73 ± 0.10 (0.54–1.05) [95% CI: 0.71–0.75] 0.054ᶜ MCA PI / Umbilical PI ratio 2.12 ± 0.35 (1.44–3.26) [95% CI: 2.05–2.19] 2.01 ± 0.25 (1.44–2.64) [95% CI: 1.96–2.06] 0.010ᶜ Note. Data are expressed as mean ± standard deviation (range) and 95% confidence interval (CI). ᵇ Mann–Whitney U test; ᶜ Student’s t -test. Abbreviations: PI = Pulsatility Index; MCA = Middle Cerebral Artery; DV = Ductus Venosus; CI = Confidence Interval. Table 3. Comparison of Fetal Cardiac Function and Morphological Parameters Between Fasting and Control Groups Parameter Fasting Group (n = 102) Control Group (n = 101) p value Mitral E (cm/s) 32.78 ± 7.37 (17.9–46.4) 31.87 ± 4.59 (20.1–43.2) 0.294ᶜ Mitral A (cm/s) 50.67 ± 8.61 (30.4–67.4) 49.87 ± 7.09 (32.6–69.7) 0.471ᶜ Mitral E/A ratio 0.64 ± 0.07 (0.47–0.79) 0.64 ± 0.05 (0.51–0.77) 0.831ᵇ Left ventricular MPI 0.54 ± 0.08 (0.30–0.74) 0.49 ± 0.08 (0.31–0.73) <0.001ᶜ Tricuspid E (cm/s) 33.41 ± 5.86 (20.5–47.1) 34.45 ± 5.56 (23.1–59.3) 0.195ᶜ Tricuspid A (cm/s) 50.62 ± 7.10 (35.2–64.6) 52.55 ± 7.10 (33.3–76.6) 0.055ᶜ Tricuspid E/A ratio 0.65 ± 0.07 (0.50–0.82) 0.65 ± 0.05 (0.50–0.85) 0.485ᵇ Right ventricular MPI 0.56 ± 0.09 (0.36–0.75) 0.53 ± 0.10 (0.27–0.77) 0.041ᶜ TAPSE (mm) 7.71 ± 1.45 (4.7–11.2) 7.54 ± 1.29 (5.4–10.5) 0.404ᶜ MAPSE (mm) 6.29 ± 1.12 (3.8–9.7) 6.25 ± 1.07 (4.0–8.6) 0.778ᶜ Fetal heart rate (bpm) 145.59 ± 8.38 (124–176) 143.92 ± 9.27 (113–171) 0.180ᶜ Left ventricular sphericity index (LVSI) 1.71 ± 0.19 (1.26–2.11) 1.70 ± 0.19 (1.31–2.26) 0.686ᶜ Right ventricular sphericity index (RVSI) 1.69 ± 0.17 (1.32–2.10) 1.67 ± 0.20 (1.24–2.37) 0.551ᶜ Cardiothoracic ratio (CTR) 0.29 ± 0.02 (0.24–0.35) 0.23 ± 0.04 (0.15–0.35) <0.001ᵇ Amniotic fluid index (AFI, cm) 11.24 ± 1.41 (8.4–14.6) 17.92 ± 1.60 (13.4–21.5) <0.001ᶜ Note. Continuous variables are presented as mean ± standard deviation (range). p < 0.05 was considered statistically significant. ᵇ Mann–Whitney U test; ᶜ Student’s t -test. Abbreviations: MPI = Myocardial Performance Index; TAPSE = Tricuspid Annular Plane Systolic Excursion; MAPSE = Mitral Annular Plane Systolic Excursion; LVSI = Left Ventricular Sphericity Index; RVSI = Right Ventricular Sphericity Index; CTR = Cardiothoracic Ratio; AFI = Amniotic Fluid Index; bpm = beats per minute. Table 4. Effect Size (Cohen’s d ) of Differences Between Fasting and Control Groups Parameter Mean (Fasting) Mean (Control) Cohen’s d Interpretation Middle Cerebral Artery PI 2.13 2.05 0.50 Medium effect Left Ventricular MPI 0.54 0.49 0.63 Moderate–large effect Right Ventricular MPI 0.56 0.53 0.41 Medium effect Cardiothoracic Ratio (CTR) 0.29 0.23 0.82 Large effect Amniotic Fluid Index (AFI) 11.24 17.92 1.35 Very large effect Note. Cohen’s d values quantify the standardized mean difference between fasting and control groups. According to Cohen’s convention: 0.2 = small, 0.5 = medium, and 0.8 or greater = large effect. Abbreviations: PI = Pulsatility Index; MPI = Myocardial Performance Index; CTR = Cardiothoracic Ratio; AFI = Amniotic Fluid Index. Table 5. Spearman Correlation Matrix Between Fetal Hemodynamic and Functional Parameters Variable LV MPI RV MPI CTR AFI MCA PI LV MPI — 0.52 0.33 –0.42 0.38 RV MPI 0.52 — 0.39 –0.35 0.29 CTR 0.33 0.39 — –0.30 0.20 AFI –0.42 –0.35 –0.30 — –0.36 MCA PI 0.38 0.29 0.20 –0.36 — Note. Spearman’s rank correlation coefficients ( rₛ ) were calculated to assess associations between fetal cardiac function and hemodynamic parameters. Bold values denote significant correlations ( p < 0.05). Abbreviations: LV MPI = Left Ventricular Myocardial Performance Index; RV MPI = Right Ventricular Myocardial Performance Index; CTR = Cardiothoracic Ratio; AFI = Amniotic Fluid Index; MCA PI = Middle Cerebral Artery Pulsatility Index. Table 6. Multiple Linear Regression Analysis for Predictors of Fetal Cardiac Function (LV MPI) and Amniotic Fluid Index (AFI) Dependent Variable Predictor β Coefficient SE t p Value 95% CI LV MPI Intercept 0.291 0.064 4.58 <0.001 [0.166, 0.417] Fasting (vs Control) 0.036 0.012 3.08 0.002 [0.013, 0.060] Gestational Weeks 0.0078 0.002 3.29 0.001 [0.003, 0.013] AFI Intercept 19.156 1.170 16.37 <0.001 [16.849, 21.463] Fasting (vs Control) –6.648 0.217 –30.60 <0.001 [–7.076, –6.219] Gestational Weeks –0.046 0.044 –1.06 0.291 [–0.133, 0.040] Note. Linear regression models were used to evaluate the independent effects of fasting status and gestational age on fetal cardiac function (LV MPI) and amniotic fluid volume (AFI). R² = 0.11 for LV MPI model and R² = 0.83 for AFI model. Abbreviations: LV MPI = Left Ventricular Myocardial Performance Index; AFI = Amniotic Fluid Index; CI = Confidence Interval; SE = Standard Error. Table 7. ROC Analysis for the Predictive Value of LV MPI in Identifying Low Amniotic Fluid (AFI < 10 cm) Predictor AUC (95% CI) Optimal Cut-off Sensitivity (%) Specificity (%) p Value LV MPI 0.52 (0.46–0.58) 0.53 55 49 0.41 Note. Receiver Operating Characteristic (ROC) analysis was conducted to determine the discriminative ability of LV MPI in predicting low amniotic fluid (AFI < 10 cm). An AUC of 0.50 represents no discrimination, while values ≥ 0.70 indicate acceptable predictive accuracy. Abbreviations: LV MPI = Left Ventricular Myocardial Performance Index; AFI = Amniotic Fluid Index; AUC = Area Under the Curve; CI = Confidence Interval. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 05 Feb, 2026 Read the published version in BMC Pregnancy and Childbirth → Version 1 posted Editorial decision: Revision requested 06 Nov, 2025 Editor assigned by journal 22 Oct, 2025 Submission checks completed at journal 22 Oct, 2025 First submitted to journal 20 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7908308","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":533661703,"identity":"e8cb3ad3-caac-4b08-9b1a-8eb3a2a7e73f","order_by":0,"name":"Deniz Taşdemir","email":"data:image/png;base64,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","orcid":"","institution":"Şanlıurfa Training and Research Hospital","correspondingAuthor":true,"prefix":"","firstName":"Deniz","middleName":"","lastName":"Taşdemir","suffix":""}],"badges":[],"createdAt":"2025-10-20 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1","display":"","copyAsset":false,"role":"figure","size":135484,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eROC Curve for LV MPI Predicting Low Amniotic Fluid (AFI \u0026lt; 10 cm\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7908308/v1/ac1e0798d8c20c8188eec2af.png"},{"id":102234803,"identity":"bbeb3c71-81eb-4555-baae-db1cab7f799c","added_by":"auto","created_at":"2026-02-09 16:13:22","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2785533,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7908308/v1/5cab6367-e795-47f8-bbe3-64315c75e0cb.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Maternal Ramadan Fasting and Fetal Cardiac Function: Subclinical Hemodynamic Alterations Revealed by Doppler Evaluation","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRamadan fasting, observed by millions of Muslims worldwide, entails abstaining from food and fluids from dawn to sunset. Although pregnant women are religiously exempt, many continue fasting for cultural and personal reasons [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Pregnancy, however, is a state of increased metabolic demand and fluid requirement, making prolonged fasting a potential physiological stressor that may influence fetal well-being [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e\u003cp\u003ePrevious studies have examined the effects of Ramadan fasting on maternal metabolism, fetal growth, and amniotic fluid volume, with largely inconsistent results [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. While most report no adverse perinatal outcomes, subtle metabolic shifts such as reduced glucose and hydration levels could theoretically affect fetal circulation and cardiac function [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eFetal cardiac performance can be objectively assessed by Doppler-derived indices including the \u003cb\u003emyocardial performance index (MPI)\u003c/b\u003e, \u003cb\u003etricuspid and mitral annular plane systolic excursions (TAPSE, MAPSE)\u003c/b\u003e, and cerebral\u0026ndash;umbilical resistance ratios [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. These parameters reflect early subclinical hemodynamic changes even in the absence of overt fetal distress. Yet, the impact of maternal fasting on these sensitive cardiovascular markers remains poorly understood.\u003c/p\u003e\u003cp\u003eTherefore, this study aimed to \u003cb\u003eevaluate the effects of maternal Ramadan fasting on fetal cardiac function and hemodynamics\u003c/b\u003e using detailed Doppler assessment. We hypothesized that fasting during pregnancy may induce \u003cb\u003esubclinical alterations\u003c/b\u003e in fetal myocardial performance and circulatory dynamics detectable by ultrasound evaluation.\u003c/p\u003e"},{"header":"Material and Methods","content":"\u003cp\u003eThis study was conducted between \u003cstrong\u003eJanuary 2025 and July 2025\u003c/strong\u003e at the \u003cstrong\u003ePerinatology Outpatient Clinic of Şanlıurfa Training and Research Hospital\u003c/strong\u003e, following approval by the \u003cstrong\u003eInstitutional Ethics Committee\u003c/strong\u003e (Approval No: HR\u0026Uuml;/25.03.01]). This prospective observational study was registered with the \u003cstrong\u003eNational Clinical Trial (NCT06900257,\u003c/strong\u003e \u003cstrong\u003eregistration date 23 March 2025\u003c/strong\u003e\u003cstrong\u003e)\u003c/strong\u003e prior to participant enrollment to ensure transparency and adherence to international research standards. All participants provided \u003cstrong\u003ewritten informed consent\u003c/strong\u003e prior to enrollment, and the study was performed in accordance with the \u003cstrong\u003eDeclaration of Helsinki\u003c/strong\u003e principles.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e\u003cem\u003eStudy Population\u003c/em\u003e\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eA total of 203 healthy pregnant women between \u003cstrong\u003e24 and 32 weeks of gestation\u003c/strong\u003e were enrolled and stratified into two groups:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003e\u003cstrong\u003eFasting group (n = 102):\u003c/strong\u003e women who observed Ramadan fasting for \u0026ge;10 consecutive days, verified by self-report and fasting logs.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eControl group (n = 101):\u003c/strong\u003e women who did not fast during the same period and were matched for maternal age (\u0026plusmn;2 years), gravidity, and gestational week (\u0026plusmn;1 week).\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion criteria\u003c/strong\u003e were: singleton pregnancy, absence of structural or chromosomal fetal anomalies, normal first- and second-trimester screening, and regular antenatal follow-up.\u003cbr\u003e\u003cstrong\u003eExclusion criteria\u003c/strong\u003e included pre-existing diabetes mellitus, hypertension, thyroid or renal disease, polyhydramnios/oligohydramnios, intrauterine growth restriction, smoking, and use of medications affecting cardiovascular or metabolic status.\u003c/p\u003e\n\u003cp\u003eMaternal demographic and obstetric data were recorded, including age, parity, pre-pregnancy BMI, gestational week, and number of fasting days.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e\u003cem\u003eUltrasound and Doppler Protocol\u003c/em\u003e\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eAll sonographic assessments were performed by a single \u003cstrong\u003ematernal\u0026ndash;fetal medicine specialist\u003c/strong\u003e with \u0026gt;10 years of experience, using a \u003cstrong\u003eGE Voluson E8 Expert\u003csup\u003e\u0026reg;\u003c/sup\u003e\u003c/strong\u003e system equipped with a\u0026nbsp;\u003cstrong\u003e2\u0026ndash;9 MHz convex transducer (C2-9-D)\u003c/strong\u003e.\u003cbr\u003eTo minimize metabolic variability, examinations in the fasting group were scheduled \u003cstrong\u003ewithin the last two hours of the fasting period\u003c/strong\u003e (typically between 5:00\u0026ndash;7:00 PM).\u003c/p\u003e\n\u003cp\u003eFetal biometric measurements (BPD, FL, AC, EFW) were recorded, followed by Doppler evaluations performed under controlled conditions:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eInsonation angle:\u003c/strong\u003e \u0026lt;30\u0026deg;, optimized for each vessel\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eFetal activity:\u003c/strong\u003e absent or minimal movement\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSweep speed:\u003c/strong\u003e 5 cm/s\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eWall motion filter:\u003c/strong\u003e 300 Hz\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSample volume:\u003c/strong\u003e 3\u0026ndash;4 mm\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eFor each vessel, \u003cstrong\u003eat least six consecutive uniform waveforms\u003c/strong\u003e were obtained and averaged.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eVascular Doppler Parameters\u003c/strong\u003e\u003c/h4\u003e\n\u003col\u003e\n \u003cli\u003e\u003cstrong\u003eUmbilical artery (UA):\u003c/strong\u003e sampled from a free-floating cord segment.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMiddle cerebral artery (MCA):\u003c/strong\u003e measured at the proximal third near its origin from the circle of Willis.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eDuctus venosus (DV):\u003c/strong\u003e visualized in the midsagittal plane, confirming triphasic waveform morphology.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eThe\u0026nbsp;\u003cstrong\u003epulsatility index (PI)\u003c/strong\u003e was calculated for each vessel.\u003cbr\u003eThe \u003cstrong\u003eMCA/UA PI ratio\u003c/strong\u003e served as an index of cerebroplacental resistance, where lower values suggest fetal circulatory redistribution.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eCardiac Functional Assessment\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eFetal cardiac function was analyzed using both \u003cstrong\u003espectral Doppler\u003c/strong\u003e and \u003cstrong\u003eM-mode\u003c/strong\u003e echocardiography:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMitral and tricuspid inflow\u003c/strong\u003e (E and A waves) measured from apical four-chamber view to calculate E/A ratios.\u003c/li\u003e\n \u003cli\u003eThe fetal MPI was calculated as (IVCT + IVRT) / ET, where IVCT is the isovolumetric contraction time, IVRT the isovolumetric relaxation time, and ET the ejection time [11].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eTAPSE\u003c/strong\u003e and \u003cstrong\u003eMAPSE\u003c/strong\u003e were obtained via M-mode along the lateral annulus of the tricuspid and mitral valves, reflecting longitudinal systolic motion.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCTR\u003c/strong\u003e and \u003cstrong\u003eVentricular Sphericity Indices (LVSI, RVSI)\u003c/strong\u003e were calculated to assess cardiac geometry and remodeling.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAmniotic Fluid Index (AFI)\u003c/strong\u003e was determined by the four-quadrant method and recorded in centimeters.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAll measurements were averaged from three consecutive cardiac cycles to minimize intraobserver variability.\u003cbr\u003e\u0026nbsp;Interobserver reproducibility was not tested due to single-operator design but intraobserver variability was maintained below 5%.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eStatistical Analysis\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eAll data were analyzed using IBM SPSS Statistics version 25.0 (IBM Corp., Armonk, NY, USA) and cross-validated with Python 3.10 (Pandas, Statsmodels, SciPy) for advanced statistical analyses.Continuous variables were expressed as\u0026nbsp;\u003cstrong\u003emean \u0026plusmn; SD and 95% confidence intervals (CI)\u003c/strong\u003e.\u003cbr\u003eThe\u0026nbsp;\u003cstrong\u003eKolmogorov\u0026ndash;Smirnov test\u003c/strong\u003e was used to assess data normality.\u003cbr\u003e\u0026nbsp;For group comparisons:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eIndependent Samples t-test\u003c/strong\u003e was applied for normally distributed data.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMann\u0026ndash;Whitney U test\u003c/strong\u003e for non-parametric data.\u003cbr\u003eCategorical variables were analyzed with the\u0026nbsp;\u003cstrong\u003eChi-square test\u003c/strong\u003e.\u003cbr\u003eStatistical significance was set at \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eTo strengthen analytical robustness beyond mean comparison, multiple complementary analyses were incorporated:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003e\u003cstrong\u003eEffect Size (Cohen\u0026rsquo;s\u0026nbsp;\u003c/strong\u003e\u003cem\u003e\u003cstrong\u003ed\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e):\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Quantified the magnitude of intergroup differences for major parameters (MCA PI, LV MPI, RV MPI, CTR, AFI).\u003cbr\u003e\u0026nbsp;Effect sizes were interpreted as small (0.2), medium (0.5), or large (\u0026ge;0.8).\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCorrelation Analysis:\u003c/strong\u003e\u003cbr\u003e\u003cstrong\u003eSpearman\u0026rsquo;s rank correlation (rₛ)\u003c/strong\u003e was employed to explore relationships among fetal cardiac and hemodynamic parameters (LV MPI, RV MPI, CTR, AFI, MCA PI).\u003cbr\u003e\u0026nbsp;Correlations were categorized as weak (r \u0026lt; 0.3), moderate (0.3\u0026ndash;0.5), or strong (\u0026gt;0.5).\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMultiple Linear Regression:\u003c/strong\u003e\u003cbr\u003eSeparate regression models were built for \u003cstrong\u003eLV MPI\u003c/strong\u003e and\u0026nbsp;\u003cstrong\u003eAFI\u003c/strong\u003e as dependent variables.\u003cbr\u003e\u0026nbsp;Independent predictors included fasting status (binary), gestational age (weeks), and fetal heart rate.\u003cbr\u003eModel adequacy was tested using \u003cstrong\u003eR\u0026sup2;\u003c/strong\u003e, \u003cstrong\u003eadjusted R\u0026sup2;\u003c/strong\u003e, \u003cstrong\u003e\u0026beta; coefficients\u003c/strong\u003e, and\u0026nbsp;\u003cstrong\u003e95% CI\u003c/strong\u003e.\u003cbr\u003eMulticollinearity was excluded with \u003cstrong\u003evariance inflation factor (VIF \u0026lt; 2.0)\u003c/strong\u003e.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eReceiver Operating Characteristic (ROC) Analysis:\u003c/strong\u003e\u003cbr\u003eThe discriminative capacity of LV MPI in identifying\u0026nbsp;\u003cstrong\u003elow amniotic fluid (AFI \u0026lt; 10 cm)\u003c/strong\u003e was assessed.\u003cbr\u003eThe\u0026nbsp;\u003cstrong\u003earea under the curve (AUC)\u003c/strong\u003e was calculated with 95% CI; values of 0.5 indicate no discrimination, 0.7\u0026ndash;0.8 acceptable, and \u0026gt;0.8 excellent.\u003cbr\u003eThe optimal cut-off was derived using \u003cstrong\u003eYouden\u0026rsquo;s Index (J = Sensitivity + Specificity \u0026ndash; 1)\u003c/strong\u003e.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePower and Sensitivity Analysis:\u003c/strong\u003e\u003cbr\u003ePost hoc power calculations demonstrated an achieved statistical power of \u003cstrong\u003e\u0026gt;0.85\u003c/strong\u003e for significant comparisons (LV MPI, CTR, AFI), confirming adequate sample size.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 203 singleton pregnancies were included in the final analysis, comprising 102 fasting and 101 control participants. The mean gestational age at assessment was similar between groups (27.1 \u0026plusmn; 2.6 vs. 26.3 \u0026plusmn; 2.1 weeks, \u003cem\u003ep\u003c/em\u003e = 0.056), whereas the mean fasting duration among fasting women was 21.7 \u0026plusmn; 4.0 days (Table 1).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFetal Doppler Hemodynamics\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUmbilical artery and ductus venosus pulsatility indices (PI) were comparable between fasting and control groups (\u003cem\u003ep\u003c/em\u003e \u0026gt; 0.05). However, the middle cerebral artery PI was significantly higher in fasting pregnancies (2.13 \u0026plusmn; 0.17 vs. 2.05 \u0026plusmn; 0.14, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001), indicating increased cerebral vascular resistance. Similarly, the MCA/UA PI ratio was significantly elevated in the fasting group (2.12 \u0026plusmn; 0.35 vs. 2.01 \u0026plusmn; 0.25, \u003cem\u003ep\u003c/em\u003e = 0.010) (Table 2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFetal Cardiac Function and Morphology\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo significant differences were found in mitral or tricuspid E/A ratios, TAPSE, or MAPSE values between groups (\u003cem\u003ep\u003c/em\u003e \u0026gt; 0.05). In contrast, both left and right ventricular myocardial performance indices (LV MPI and RV MPI) were significantly higher among fasting women (0.54 \u0026plusmn; 0.08 vs. 0.49 \u0026plusmn; 0.08, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001; 0.56 \u0026plusmn; 0.09 vs. 0.53 \u0026plusmn; 0.10, \u003cem\u003ep\u003c/em\u003e = 0.041, respectively), suggesting mild subclinical cardiac loading. Cardiothoracic ratio (CTR) was notably increased in the fasting group (0.29 \u0026plusmn; 0.02 vs. 0.23 \u0026plusmn; 0.04, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001), while amniotic fluid index (AFI) was markedly lower (11.24 \u0026plusmn; 1.41 vs. 17.92 \u0026plusmn; 1.60 cm, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001) (Table 3).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEffect Size and Clinical Significance\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e analysis demonstrated clinically meaningful differences for several parameters (Table 4). The largest effect was observed for AFI (\u003cem\u003ed\u003c/em\u003e = 1.35, very large), followed by CTR (\u003cem\u003ed\u003c/em\u003e = 0.82, large) and LV MPI (\u003cem\u003ed\u003c/em\u003e = 0.63, moderate\u0026ndash;large). These findings support the presence of physiologic alterations in both fetal cardiac performance and fluid balance during maternal fasting.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCorrelation Analysis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSpearman\u0026rsquo;s correlation matrix revealed significant associations between cardiac and hemodynamic variables (Table 5). LV MPI correlated positively with RV MPI (\u003cem\u003er\u003c/em\u003e = 0.52, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001) and CTR (\u003cem\u003er\u003c/em\u003e = 0.33, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05), but negatively with AFI (\u003cem\u003er\u003c/em\u003e = \u0026ndash;0.42, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). Similarly, MCA PI was inversely associated with AFI (\u003cem\u003er\u003c/em\u003e = \u0026ndash;0.36, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05). These results suggest that increased fetal cardiac load and cerebral vascular resistance are accompanied by reduced amniotic fluid volume, reflecting a potential systemic adaptation to maternal fasting.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eRegression Analysis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMultiple linear regression models identified fasting as an independent predictor of elevated LV MPI and reduced AFI after adjustment for gestational age (Table 6). Fasting status was significantly associated with higher LV MPI (\u0026beta; = 0.036, \u003cem\u003ep\u003c/em\u003e = 0.002) and lower AFI (\u0026beta; = \u0026ndash;6.648, \u003cem\u003ep\u003c/em\u003e \u0026lt; 0.001). Gestational age showed a modest positive association with LV MPI (\u0026beta; = 0.0078, \u003cem\u003ep\u003c/em\u003e = 0.001) but had no significant effect on AFI (\u003cem\u003ep\u003c/em\u003e = 0.291). The models explained 11% and 83% of the variance in LV MPI and AFI, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eROC Curve Analysis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eReceiver operating characteristic (ROC) analysis was performed to evaluate the ability of LV MPI to predict low amniotic fluid volume (AFI \u0026lt; 10 cm). The area under the curve (AUC) was 0.52 (95% CI: 0.46\u0026ndash;0.58), indicating limited discriminative power of LV MPI in detecting pregnancies with reduced AFI (Table 7, Figure 1). Although the predictive accuracy was modest, the observed relationship between higher MPI and lower AFI suggests underlying hemodynamic stress that may not yet manifest as overt fetal compromise.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis prospective study explored the hemodynamic and myocardial responses of fetuses to maternal Ramadan fasting using comprehensive Doppler echocardiography. The results demonstrated significantly higher \u003cstrong\u003eMCA PI\u003c/strong\u003e, \u003cstrong\u003eleft and right ventricular myocardial performance indices (LV MPI, RV MPI)\u003c/strong\u003e, and \u003cstrong\u003eCTR\u003c/strong\u003e in fasting pregnancies, while the \u003cstrong\u003eAFI\u003c/strong\u003e was notably reduced. Conversely, \u003cstrong\u003eumbilical and ductus venosus (DV) Doppler indices\u003c/strong\u003e, as well as \u003cstrong\u003eTAPSE\u003c/strong\u003e, \u003cstrong\u003eMAPSE\u003c/strong\u003e, and heart rate, remained unchanged. These findings suggest that maternal fasting induces \u003cstrong\u003esubclinical, adaptive cardiovascular responses\u003c/strong\u003e in the fetus rather than pathological compromise.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFetal Cerebral Hemodynamics\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe increase in MCA PI observed in fasting pregnancies implies a mild rise in cerebrovascular resistance. Previous research has reported inconsistent effects of fasting on cerebral blood flow [5,6].\u003cbr\u003eWhile some authors found no significant differences in MCA or umbilical indices [5,7], our results align with the physiological hypothesis that\u0026nbsp;\u003cstrong\u003ematernal hypoglycemia and dehydration toward the end of the fasting day\u003c/strong\u003e may transiently increase cerebrovascular impedance [12,13].\u003cbr\u003eCerebral autoregulation allows the fetus to maintain oxygen delivery despite short-term metabolic fluctuations [14]. Thus, elevated MCA PI in our cohort likely reflects\u0026nbsp;\u003cstrong\u003ereversible metabolic vasoreactivity\u003c/strong\u003e rather than hypoxic redistribution.\u003cbr\u003e\u0026nbsp;This adaptive response may differ depending on the duration of fasting, gestational age, and climatic conditions, particularly during longer summer fasts [4].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFetal Myocardial Performance\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe\u0026nbsp;\u003cstrong\u003eincrease in LV and RV MPI\u003c/strong\u003e among fasting women represents the most notable and novel finding of this study. MPI integrates both systolic and diastolic performance by combining isovolumetric contraction and relaxation times relative to ejection time [11].\u003cbr\u003ePrevious studies have shown that elevated MPI is an early sign of\u0026nbsp;\u003cstrong\u003eventricular loading alteration\u003c/strong\u003e in conditions such as intrauterine growth restriction and gestational diabetes [9,10,15].\u003cbr\u003e\u0026nbsp;The observed MPI elevation in fasting pregnancies, independent of gestational age, may result from subtle reductions in preload or changes in myocardial relaxation secondary to transient maternal dehydration and reduced glucose supply [12,16].\u003cbr\u003eImportantly, \u003cstrong\u003eTAPSE and MAPSE\u003c/strong\u003e values remained stable, indicating preserved systolic contractility and supporting the concept of \u003cstrong\u003ediastolic sensitivity to metabolic shifts\u003c/strong\u003e as the earliest detectable myocardial response [9].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eCardiac Morphology and Circulatory Load\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAn increased \u003cstrong\u003ecardiothoracic ratio (CTR)\u003c/strong\u003e was also observed among fasting women. Although CTR has been associated with pathological cardiomegaly in fetal compromise [17], modest increases in CTR without changes in sphericity indices (LVSI, RVSI) likely indicate\u0026nbsp;\u003cstrong\u003etemporary volume adaptation\u003c/strong\u003e or mild preload elevation.\u003cbr\u003e\u0026nbsp;Comparable findings have been reported in adaptive fetal remodeling under mild hemodynamic stress [18,19].\u003cbr\u003eThe absence of structural deformation or venous congestion in our study supports that these cardiac modifications are \u003cstrong\u003efunctional and reversible\u003c/strong\u003e rather than pathologic.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAmniotic Fluid and Placental Perfusion\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe reduction in \u003cstrong\u003eAFI\u003c/strong\u003e observed among fasting women is consistent with several previous studies [20,21], which attributed the decrease primarily to\u0026nbsp;\u003cstrong\u003ematernal dehydration and reduced renal plasma flow\u003c/strong\u003e.\u003cbr\u003e\u0026nbsp;However, other investigations did not find significant AFI changes [5,7], likely due to differences in fasting duration, environmental conditions, and fluid intake habits [4,22].\u003cbr\u003eIn our cohort, conducted in southeastern T\u0026uuml;rkiye during long fasting hours, lower AFI likely reflects\u0026nbsp;\u003cstrong\u003ematernal water restriction\u003c/strong\u003e rather than placental dysfunction.\u003cbr\u003eThe negative correlation between AFI and MPI further suggests an \u003cstrong\u003einterrelated compensatory mechanism\u003c/strong\u003e: as placental flow and amniotic fluid decrease, fetal myocardial workload subtly increases to maintain adequate circulation [9,10].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eIntegrative Physiological Interpretation\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCollectively, the combination of increased MPI, elevated MCA PI, and reduced AFI represents a\u0026nbsp;\u003cstrong\u003ecoordinated, subclinical fetal response\u003c/strong\u003e to transient maternal metabolic and hydration changes.\u003cbr\u003eThis adaptive pattern supports the concept of\u0026nbsp;\u003cstrong\u003efetal cardiovascular resilience\u003c/strong\u003e, wherein the fetus maintains hemodynamic homeostasis through autonomic and myocardial adjustments [11,14].\u003cbr\u003e\u0026nbsp;Such physiological buffering likely explains why large population studies found no adverse effects of Ramadan fasting on birth weight or neonatal outcomes [8,23].\u003cbr\u003e\u0026nbsp;Nevertheless, this adaptive reserve may be limited in pregnancies with compromised placental function, such as preeclampsia or fetal growth restriction [24-26].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eClinical Implications\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOur results reinforce that Ramadan fasting is\u0026nbsp;\u003cstrong\u003egenerally safe in healthy pregnancies\u003c/strong\u003e, provided that hydration and caloric intake are adequate [1,2].\u003cbr\u003eHowever, the observed Doppler-based changes highlight the need for\u0026nbsp;\u003cstrong\u003eindividualized counseling and monitoring\u003c/strong\u003e.\u003cbr\u003eClinicians should recommend adequate fluid intake during non-fasting hours, shorter fasting durations when possible, and\u0026nbsp;\u003cstrong\u003emid-Ramadan fetal Doppler assessment\u003c/strong\u003e for women at increased risk.\u003cbr\u003e\u0026nbsp;In cases with pre-existing maternal or placental compromise, temporary fasting exemptions should be considered to prevent potential fetal stress [5,6].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eStrengths and Limitations\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe strengths of this study include its \u003cstrong\u003eprospective design\u003c/strong\u003e, \u003cstrong\u003ehomogeneous cohort\u003c/strong\u003e, and\u0026nbsp;\u003cstrong\u003ecomprehensive cardiac assessment\u003c/strong\u003e using multiple Doppler-derived indices.\u003cbr\u003eAdvanced statistical modeling\u0026mdash;such as\u0026nbsp;\u003cstrong\u003eeffect size analysis, multivariable regression, and ROC curve evaluation\u003c/strong\u003e\u0026mdash;enhanced interpretative depth.\u003cbr\u003eHowever, this was a \u003cstrong\u003esingle-center study\u003c/strong\u003e, and\u0026nbsp;\u003cstrong\u003ematernal biochemical markers\u003c/strong\u003e (e.g., glucose, insulin, ketone bodies) were not measured concurrently.\u003cbr\u003eAdditionally,\u0026nbsp;\u003cstrong\u003elong-term neonatal outcomes\u003c/strong\u003e were not evaluated, and thus the persistence of these subclinical cardiac adaptations remains uncertain.\u003cbr\u003eFinally, \u003cstrong\u003eseasonal and geographic variability\u003c/strong\u003e may influence fasting effects, necessitating multicenter replication under different environmental conditions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFuture Directions\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFuture studies should integrate\u0026nbsp;\u003cstrong\u003ematernal metabolic profiling, serial fetal Doppler monitoring, and postnatal echocardiography\u003c/strong\u003e to delineate the temporal dynamics of these adaptations.\u003cbr\u003eEmerging technologies, including \u003cstrong\u003efetal strain imaging\u003c/strong\u003e, \u003cstrong\u003e3D cardiac volumetry\u003c/strong\u003e, and\u0026nbsp;\u003cstrong\u003eAI-based Doppler waveform analysis\u003c/strong\u003e, may provide greater insight into subtle myocardial and vascular changes.\u003cbr\u003eExpanding research to include \u003cstrong\u003ehigh-risk pregnancies\u003c/strong\u003e will be critical to identify thresholds where fasting transitions from adaptive to detrimental.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn conclusion, maternal Ramadan fasting appears to induce \u003cb\u003etransient and reversible fetal cardiovascular adjustments\u003c/b\u003e, characterized by increased MPI and MCA PI and reduced AFI, without overt signs of fetal distress.\u003c/p\u003e\u003cp\u003eThese findings highlight the \u003cb\u003eadaptive capacity of the fetal cardiovascular system\u003c/b\u003e and support the safety of fasting among healthy women under proper nutritional and medical supervision.\u003c/p\u003e\u003cp\u003eNonetheless, careful \u003cb\u003eindividualized assessment\u003c/b\u003e remains essential, and further longitudinal studies are needed to clarify the long-term significance of these subtle hemodynamic changes.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthical Approval\u003c/strong\u003e\u003cbr\u003eThis study was conducted in compliance with the ethical principles outlined in the Declaration of Helsinki. Ethical approval was obtained from the \u003cstrong\u003eHarran University\u003c/strong\u003e Ethics Committee under approval number HR\u0026Uuml;/25.03.01. This prospective observational study was registered with the \u003cstrong\u003eNational Clinical Trial (NCT06900257)\u003c/strong\u003e prior to participant enrollment to ensure transparency and adherence to international research standards. Written informed consent was obtained from all participants prior to their inclusion in the study. Participants had the right to withdraw from the study at any time without consequences. All collected data were anonymized and stored securely to maintain confidentiality.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Following ethics committee approval, written informed consent forms were obtained from all participants for their participation in the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for Publication\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;This study does not include any identifying information, and all data were anonymized to ensure participant confidentiality. There are no restrictions or concerns regarding the publication of this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of Data and Materials\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;Patient data used in this study are securely stored in the hospital\u0026apos;s automation system and are available upon reasonable request, provided that participant confidentiality is maintained.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;The authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDeniz Taşdemir\u003c/strong\u003e was solely responsible for the conception and design of the study, data collection, ultrasonographic examinations, statistical analysis, interpretation of results, and manuscript drafting and revision. The author approved the final version of the manuscript and agrees to be accountable for all aspects of the work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003cbr\u003e\u0026nbsp;No financial support was received for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003cbr\u003eThe authors would like to thank the medical staff and patients at \u003cstrong\u003ePerinatology Outpatient Clinic of Şanlıurfa Training and Research Hospital\u003c/strong\u003e for their valuable contributions to this research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAzizi F. Islamic fasting and health. \u003cem\u003eAnn Nutr Metab.\u003c/em\u003e 2010;56(4):273\u0026ndash;282.\u003c/li\u003e\n \u003cli\u003eJoosoph J, Abu J, Yu SL. A survey of fasting during pregnancy. \u003cem\u003eSingapore Med J.\u003c/em\u003e 2004;45(12):583\u0026ndash;586.\u003c/li\u003e\n \u003cli\u003eRobinson T, Raisler J. \u0026ldquo;Each one is a doctor for herself\u0026rdquo;: Ramadan fasting among pregnant Muslim women in the United States. \u003cem\u003eEthn Dis.\u003c/em\u003e 2005;15(1 Suppl 1):S1-99\u0026ndash;103.\u003c/li\u003e\n \u003cli\u003eLeiper JB, Molla AM. Effects on health of fluid restriction during fasting in Ramadan. \u003cem\u003eEur J Clin Nutr.\u003c/em\u003e 2003;57(Suppl 2):S30\u0026ndash;S38.\u003c/li\u003e\n \u003cli\u003eHızlı D, Yılmaz SS, Onaran Y, Kafalı H, Danışman N, Mollamahmutoğlu L. Impact of maternal fasting during Ramadan on fetal Doppler parameters, maternal lipid levels, and neonatal outcomes. \u003cem\u003eJ Matern Fetal Neonatal Med.\u003c/em\u003e 2012;25(7):975\u0026ndash;977.\u003c/li\u003e\n \u003cli\u003eDikensoy E, Balat O, Cebesoy B, et al. The effect of Ramadan fasting on maternal serum lipids, cortisol levels, and fetal development. \u003cem\u003eArch Gynecol Obstet.\u003c/em\u003e 2009;279(2):119\u0026ndash;123.\u003c/li\u003e\n \u003cli\u003eMirghani HM, Weerasinghe DSL, Ezimokhai M, Smith JR. The effect of maternal fasting on the fetal biophysical profile. \u003cem\u003eInt J Gynecol Obstet.\u003c/em\u003e 2003;81(1):17\u0026ndash;21.\u003c/li\u003e\n \u003cli\u003eKavehmanesh Z, Abolghasemi H. Maternal Ramadan fasting and neonatal health. \u003cem\u003eJ Perinatol.\u003c/em\u003e 2004;24(12):748\u0026ndash;750.\u003c/li\u003e\n \u003cli\u003eCrispi F, Valenzuela-Alcaraz B, Cruz-Lemini M, Gratac\u0026oacute;s E. Ultrasound assessment of fetal cardiac function. \u003cem\u003eAustralas J Ultrasound Med.\u003c/em\u003e 2013;16(4):158\u0026ndash;167.\u003c/li\u003e\n \u003cli\u003eSanhal CY, Daglar HK, Kara O, Uygur D, Yucel A. Assessment of fetal myocardial performance index in women with gestational diabetes. \u003cem\u003eJ Obstet Gynaecol Res.\u003c/em\u003e 2017;43(1):65\u0026ndash;72.\u003c/li\u003e\n \u003cli\u003eAbuhamad AZ, Chaoui R. \u003cem\u003eA Practical Guide to Fetal Echocardiography: Normal and Abnormal Hearts.\u003c/em\u003e Philadelphia: Lippincott Williams \u0026amp; Wilkins; 2012.\u003c/li\u003e\n \u003cli\u003ePrentice AM, Prentice A, Lamb WH, Lunn PG, Austin S. Metabolic consequences of fasting during Ramadan in pregnant and lactating women. \u003cem\u003eHum Nutr Clin Nutr.\u003c/em\u003e 1983;37(4):283\u0026ndash;294.\u003c/li\u003e\n \u003cli\u003eMalhotra A, Scott PH, Scott J, Gee H, Wharton BA. Metabolic changes in Asian Muslim pregnant mothers observing the Ramadan fast in Britain. \u003cem\u003eBr J Nutr.\u003c/em\u003e 1989;61(3):663\u0026ndash;672.\u003c/li\u003e\n \u003cli\u003eMilley JR, Simmons MA. Metabolic requirements for fetal growth. \u003cem\u003eClin Perinatol.\u003c/em\u003e 1979;6(2):365\u0026ndash;376.\u003c/li\u003e\n \u003cli\u003eNiewiadomska-Jarosik K, Zamojska J, Zamecznik A, Wosiak A, Jarosik P, Stańczyk J. Myocardial dysfunction in children with intrauterine growth restriction: an echocardiographic study. \u003cem\u003eCardiovasc J Afr.\u003c/em\u003e 2017;28(1):36\u0026ndash;39.\u003c/li\u003e\n \u003cli\u003eBenelli Aksungur F, Eren A, Pure S, Teskin OAtes G. Effects of intermittent fasting on serum lipid levels, coagulation status and plasma homocysteine levels. Ann Nutr Metab. 2005;49(2):77\u0026ndash;82.\u003c/li\u003e\n \u003cli\u003ePaladini D, Chita SK, Allan LD. Prenatal measurement of cardiothoracic ratio in evaluation of heart disease. \u003cem\u003eArch Dis Child.\u003c/em\u003e 1990;65(1):20\u0026ndash;23.\u003c/li\u003e\n \u003cli\u003eValenzuela-Alcaraz B, Crispi F, Cruz-Lemini M, Bijnens B, Garc\u0026iacute;a-Otero L, Sitges M, et al. Differential effect of assisted reproductive technology and small-for-gestational-age on fetal cardiac remodeling. \u003cem\u003eUltrasound Obstet Gynecol.\u003c/em\u003e 2017;50(1):63\u0026ndash;70.\u003c/li\u003e\n \u003cli\u003eDeVore GR, Zaretsky M, Gumina DL, Hobbins JC. Right and left ventricular sphericity index is abnormal in small-for-gestational-age fetuses. \u003cem\u003eUltrasound Obstet Gynecol.\u003c/em\u003e 2018;52(2):243\u0026ndash;249.\u003c/li\u003e\n \u003cli\u003eKamyabi Z, Naderi T. The effect of Ramadan fasting on amniotic fluid volume. \u003cem\u003eSaudi Med J.\u003c/em\u003e 2004;25(1):45\u0026ndash;46.\u003c/li\u003e\n \u003cli\u003eSeckin KD, Yeral MI, Karslı MF, Gultekin IB. Effect of maternal fasting for religious beliefs on fetal sonographic findings and neonatal outcomes. \u003cem\u003eInt J Gynecol Obstet.\u003c/em\u003e 2014;126(2):123\u0026ndash;125.\u003c/li\u003e\n \u003cli\u003eBogdan A, Bouchareb B, Touitou Y. Ramadan fasting alters endocrine and neuroendocrine circadian patterns. \u003cem\u003eLife Sci.\u003c/em\u003e 2001;68(14):1607\u0026ndash;1615.\u003c/li\u003e\n \u003cli\u003eCross JH, Eminson J, Wharton BA. Ramadan and birth weight at full term in Asian Moslem pregnant women in Birmingham. \u003cem\u003eArch Dis Child.\u003c/em\u003e 1990;65(10):1053\u0026ndash;1056.\u003c/li\u003e\n \u003cli\u003eEbrashy A, Azmy O, Ibrahim M, Waly M, Edris A. Middle cerebral/umbilical artery resistance index ratio as sensitive parameter for fetal well-being and neonatal outcome in patients with preeclampsia: case-control study. Croat Med J. 2005 Oct;46(5):821-5. PMID: 16158478.\u003c/li\u003e\n \u003cli\u003e\u0026Ouml;zeren M, Din\u0026ccedil; H, Ekmen \u0026Uuml;, Senekayli C, Aydemir V. Umbilical and middle cerebral artery Doppler indices in patients with preeclampsia. \u003cem\u003eEur J Obstet Gynecol Reprod Biol.\u003c/em\u003e 1999;82(1):11\u0026ndash;16.\u003c/li\u003e\n \u003cli\u003eMakhseed M, Jirous J, Ahmed MA, Viswanathan DL. Middle cerebral artery to umbilical artery resistance index ratio in the prediction of neonatal outcome. \u003cem\u003eInt J Gynecol Obstet.\u003c/em\u003e 2000;71(2):119\u0026ndash;125.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1. Comparison of Gestational Age and Fasting Duration Between Fasting and Control Groups\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFasting Group (n = 102)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eControl Group (n = 101)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eGestational age (weeks)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e27.1 \u0026plusmn; 2.6 (24\u0026ndash;34) [95% CI: 26.6\u0026ndash;27.7]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e26.3 \u0026plusmn; 2.1 (24\u0026ndash;31.5) [95% CI: 25.9\u0026ndash;26.8]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.056ᵇ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFasting duration (days)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e21.7 \u0026plusmn; 4.0 (13\u0026ndash;29) [95% CI: 20.9\u0026ndash;22.5]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Continuous variables are presented as mean \u0026plusmn; standard deviation (range) and 95% confidence interval (CI).\u003cbr\u003e\u0026nbsp;ᵇ Mann\u0026ndash;Whitney U test was used for non-normally distributed data.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e CI = Confidence Interval.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2. Comparison of Fetal Doppler Pulsatility Index (PI) Parameters Between Fasting and Control Groups\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFasting Group (n = 102)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eControl Group (n = 101)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eUmbilical artery PI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.02 \u0026plusmn; 0.16 (0.65\u0026ndash;1.36) [95% CI: 0.99\u0026ndash;1.06]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.03 \u0026plusmn; 0.15 (0.74\u0026ndash;1.35) [95% CI: 1.03\u0026ndash;1.06]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.890ᵇ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMiddle cerebral artery (MCA) PI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.13 \u0026plusmn; 0.17 (1.82\u0026ndash;2.64) [95% CI: 2.10\u0026ndash;2.17]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.05 \u0026plusmn; 0.14 (1.79\u0026ndash;2.45) [95% CI: 2.02\u0026ndash;2.07]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eDuctus venosus (DV) PI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.77 \u0026plusmn; 0.15 (0.41\u0026ndash;1.34) [95% CI: 0.74\u0026ndash;0.80]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.73 \u0026plusmn; 0.10 (0.54\u0026ndash;1.05) [95% CI: 0.71\u0026ndash;0.75]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.054ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMCA PI / Umbilical PI ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.12 \u0026plusmn; 0.35 (1.44\u0026ndash;3.26) [95% CI: 2.05\u0026ndash;2.19]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.01 \u0026plusmn; 0.25 (1.44\u0026ndash;2.64) [95% CI: 1.96\u0026ndash;2.06]\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.010ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Data are expressed as mean \u0026plusmn; standard deviation (range) and 95% confidence interval (CI).\u003cbr\u003eᵇ Mann\u0026ndash;Whitney U test; ᶜ Student\u0026rsquo;s \u003cem\u003et\u003c/em\u003e-test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e PI = Pulsatility Index; MCA = Middle Cerebral Artery; DV = Ductus Venosus; CI = Confidence Interval.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3. Comparison of Fetal Cardiac Function and Morphological Parameters Between Fasting and Control Groups\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eFasting Group (n = 102)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eControl Group (n = 101)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMitral E (cm/s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e32.78 \u0026plusmn; 7.37 (17.9\u0026ndash;46.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e31.87 \u0026plusmn; 4.59 (20.1\u0026ndash;43.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.294ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMitral A (cm/s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50.67 \u0026plusmn; 8.61 (30.4\u0026ndash;67.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e49.87 \u0026plusmn; 7.09 (32.6\u0026ndash;69.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.471ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMitral E/A ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.64 \u0026plusmn; 0.07 (0.47\u0026ndash;0.79)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.64 \u0026plusmn; 0.05 (0.51\u0026ndash;0.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.831ᵇ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLeft ventricular MPI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.54 \u0026plusmn; 0.08 (0.30\u0026ndash;0.74)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.49 \u0026plusmn; 0.08 (0.31\u0026ndash;0.73)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTricuspid E (cm/s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e33.41 \u0026plusmn; 5.86 (20.5\u0026ndash;47.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e34.45 \u0026plusmn; 5.56 (23.1\u0026ndash;59.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.195ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTricuspid A (cm/s)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e50.62 \u0026plusmn; 7.10 (35.2\u0026ndash;64.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e52.55 \u0026plusmn; 7.10 (33.3\u0026ndash;76.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.055ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTricuspid E/A ratio\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.65 \u0026plusmn; 0.07 (0.50\u0026ndash;0.82)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.65 \u0026plusmn; 0.05 (0.50\u0026ndash;0.85)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.485ᵇ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eRight ventricular MPI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.56 \u0026plusmn; 0.09 (0.36\u0026ndash;0.75)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.53 \u0026plusmn; 0.10 (0.27\u0026ndash;0.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.041ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eTAPSE (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.71 \u0026plusmn; 1.45 (4.7\u0026ndash;11.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e7.54 \u0026plusmn; 1.29 (5.4\u0026ndash;10.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.404ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMAPSE (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.29 \u0026plusmn; 1.12 (3.8\u0026ndash;9.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e6.25 \u0026plusmn; 1.07 (4.0\u0026ndash;8.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.778ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eFetal heart rate (bpm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e145.59 \u0026plusmn; 8.38 (124\u0026ndash;176)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e143.92 \u0026plusmn; 9.27 (113\u0026ndash;171)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.180ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLeft ventricular sphericity index (LVSI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.71 \u0026plusmn; 0.19 (1.26\u0026ndash;2.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.70 \u0026plusmn; 0.19 (1.31\u0026ndash;2.26)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.686ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eRight ventricular sphericity index (RVSI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.69 \u0026plusmn; 0.17 (1.32\u0026ndash;2.10)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.67 \u0026plusmn; 0.20 (1.24\u0026ndash;2.37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.551ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eCardiothoracic ratio (CTR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.29 \u0026plusmn; 0.02 (0.24\u0026ndash;0.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.23 \u0026plusmn; 0.04 (0.15\u0026ndash;0.35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001ᵇ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAmniotic fluid index (AFI, cm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11.24 \u0026plusmn; 1.41 (8.4\u0026ndash;14.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17.92 \u0026plusmn; 1.60 (13.4\u0026ndash;21.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001ᶜ\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Continuous variables are presented as mean \u0026plusmn; standard deviation (range).\u0026nbsp;\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05 was considered statistically significant.\u003cbr\u003eᵇ Mann\u0026ndash;Whitney U test; ᶜ Student\u0026rsquo;s \u003cem\u003et\u003c/em\u003e-test.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e MPI = Myocardial Performance Index; TAPSE = Tricuspid Annular Plane Systolic Excursion; MAPSE = Mitral Annular Plane Systolic Excursion; LVSI = Left Ventricular Sphericity Index; RVSI = Right Ventricular Sphericity Index; CTR = Cardiothoracic Ratio; AFI = Amniotic Fluid Index; bpm = beats per minute.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4. Effect Size (Cohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e) of Differences Between Fasting and Control Groups\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eParameter\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMean (Fasting)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMean (Control)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCohen\u0026rsquo;s \u003cem\u003ed\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eInterpretation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eMiddle Cerebral Artery PI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e2.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMedium effect\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLeft Ventricular MPI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.63\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eModerate\u0026ndash;large effect\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eRight Ventricular MPI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eMedium effect\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eCardiothoracic Ratio (CTR)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.23\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eLarge effect\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eAmniotic Fluid Index (AFI)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e11.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e17.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eVery large effect\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Cohen\u0026rsquo;s\u0026nbsp;\u003cem\u003ed\u003c/em\u003e values quantify the standardized mean difference between fasting and control groups.\u003cbr\u003e\u0026nbsp;According to Cohen\u0026rsquo;s convention: 0.2 = small, 0.5 = medium, and 0.8 or greater = large effect.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e PI = Pulsatility Index; MPI = Myocardial Performance Index; CTR = Cardiothoracic Ratio; AFI = Amniotic Fluid Index.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 5. Spearman Correlation Matrix Between Fetal Hemodynamic and Functional Parameters\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eVariable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLV MPI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eRV MPI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCTR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAFI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMCA PI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLV MPI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026ndash;0.42\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eRV MPI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.39\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eCTR\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.39\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.20\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAFI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026ndash;0.42\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;0.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026ndash;0.36\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eMCA PI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.20\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026ndash;0.36\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026mdash;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Spearman\u0026rsquo;s rank correlation coefficients (\u003cem\u003erₛ\u003c/em\u003e) were calculated to assess associations between fetal cardiac function and hemodynamic parameters.\u003cbr\u003eBold values denote significant correlations (\u003cem\u003ep\u003c/em\u003e \u0026lt; 0.05).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e LV MPI = Left Ventricular Myocardial Performance Index; RV MPI = Right Ventricular Myocardial Performance Index; CTR = Cardiothoracic Ratio; AFI = Amniotic Fluid Index; MCA PI = Middle Cerebral Artery Pulsatility Index.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6. Multiple Linear Regression Analysis for Predictors of Fetal Cardiac Function (LV MPI) and Amniotic Fluid Index (AFI)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eDependent Variable\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePredictor\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026beta; Coefficient\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSE\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003et\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u003cem\u003ep\u003c/em\u003e\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e95% CI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eLV MPI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIntercept\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.291\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.064\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e4.58\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[0.166, 0.417]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFasting (vs Control)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.036\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.012\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.08\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[0.013, 0.060]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eGestational Weeks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.0078\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.002\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e3.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[0.003, 0.013]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAFI\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eIntercept\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e19.156\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e1.170\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e16.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026lt;0.001\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[16.849, 21.463]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eFasting (vs Control)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026ndash;6.648\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.217\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;30.60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[\u0026ndash;7.076, \u0026ndash;6.219]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003eGestational Weeks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;0.046\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.044\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u0026ndash;1.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.291\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e[\u0026ndash;0.133, 0.040]\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Linear regression models were used to evaluate the independent effects of fasting status and gestational age on fetal cardiac function (LV MPI) and amniotic fluid volume (AFI).\u003cbr\u003e\u0026nbsp;R\u0026sup2; = 0.11 for LV MPI model and R\u0026sup2; = 0.83 for AFI model.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e LV MPI = Left Ventricular Myocardial Performance Index; AFI = Amniotic Fluid Index; CI = Confidence Interval; SE = Standard Error.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 7. ROC Analysis for the Predictive Value of LV MPI in Identifying Low Amniotic Fluid (AFI \u0026lt; 10 cm)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"0\" cellpadding=\"0\" class=\"fr-table-selection-hover\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ePredictor\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eAUC (95% CI)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eOptimal Cut-off\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSensitivity (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003eSpecificity (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e\u003cstrong\u003ep Value\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd\u003e\n \u003cp\u003eLV MPI\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.52 (0.46\u0026ndash;0.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e49\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd\u003e\n \u003cp\u003e0.41\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote.\u003c/strong\u003e Receiver Operating Characteristic (ROC) analysis was conducted to determine the discriminative ability of LV MPI in predicting low amniotic fluid (AFI \u0026lt; 10 cm).\u003cbr\u003e\u0026nbsp;An AUC of 0.50 represents no discrimination, while values \u0026ge; 0.70 indicate acceptable predictive accuracy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e LV MPI = Left Ventricular Myocardial Performance Index; AFI = Amniotic Fluid Index; AUC = Area Under the Curve; CI = Confidence Interval.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Ramadan fasting, pregnancy, fetal cardiac function, myocardial performance index (MPI), Doppler ultrasonography, amniotic fluid index (AFI)","lastPublishedDoi":"10.21203/rs.3.rs-7908308/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7908308/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackround and Objectives:\u003c/h2\u003e\u003cp\u003eTo evaluate the impact of maternal Ramadan fasting on fetal cardiac function and hemodynamics using comprehensive Doppler echocardiography, emphasizing subclinical myocardial and circulatory adaptations.\u003c/p\u003e\u003ch2\u003eMaterials and Methods:\u003c/h2\u003e\u003cp\u003eIn this prospective study, 203 healthy singleton pregnancies between 24 and 32 weeks of gestation were examined\u0026mdash;102 women who fasted for \u0026ge;\u0026thinsp;10 days during Ramadan and 101 non-fasting controls. The study was prospectively registered with the National Clinical Trial (NCT06900257, registration date 23 March 2025). Doppler assessments included umbilical, middle cerebral, and ductus venosus pulsatility indices (PI), cerebroplacental ratio, and cardiac parameters: left and right myocardial performance indices (LV MPI, RV MPI), tricuspid and mitral annular plane systolic excursions (TAPSE, MAPSE), cardiothoracic ratio (CTR), and amniotic fluid index (AFI). Statistical analyses were performed using IBM SPSS v25.0 and Python 3.10, including correlation, regression, and ROC analysis.\u003c/p\u003e\u003ch2\u003eResults:\u003c/h2\u003e\u003cp\u003eFasting pregnancies demonstrated significantly higher MCA PI (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), LV MPI (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), RV MPI (p\u0026thinsp;=\u0026thinsp;0.041), and CTR (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and lower AFI (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001) than controls. Umbilical and ductus venosus PI, TAPSE, and MAPSE did not differ significantly. LV MPI correlated positively with CTR (r\u0026thinsp;=\u0026thinsp;0.33) and inversely with AFI (r = \u0026minus;\u0026thinsp;0.42). Fasting independently predicted increased LV MPI and decreased AFI. ROC analysis showed limited predictive power of MPI for low AFI (AUC\u0026thinsp;=\u0026thinsp;0.52).\u003c/p\u003e\u003ch2\u003eConclusions:\u003c/h2\u003e\u003cp\u003eMaternal Ramadan fasting induces mild, reversible fetal cardiovascular adaptations\u0026mdash;characterized by increased MPI and MCA PI and reduced AFI\u0026mdash;without evidence of fetal distress. These findings emphasize fetal hemodynamic resilience but support individualized monitoring during fasting in pregnancy.\u003c/p\u003e","manuscriptTitle":"Maternal Ramadan Fasting and Fetal Cardiac Function: Subclinical Hemodynamic Alterations Revealed by Doppler Evaluation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-28 16:34:00","doi":"10.21203/rs.3.rs-7908308/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-11-06T06:45:27+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-23T01:49:47+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-23T01:48:54+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Pregnancy and Childbirth","date":"2025-10-20T18:49:10+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-pregnancy-and-childbirth","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"prch","sideBox":"Learn more about [BMC Pregnancy and Childbirth](http://bmcpregnancychildbirth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/prch/default.aspx","title":"BMC Pregnancy and Childbirth","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bf8122ff-4797-4cda-b885-0fe6f157aa12","owner":[],"postedDate":"October 28th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2026-02-09T16:08:50+00:00","versionOfRecord":{"articleIdentity":"rs-7908308","link":"https://doi.org/10.1186/s12884-026-08683-4","journal":{"identity":"bmc-pregnancy-and-childbirth","isVorOnly":false,"title":"BMC Pregnancy and Childbirth"},"publishedOn":"2026-02-05 15:59:41","publishedOnDateReadable":"February 5th, 2026"},"versionCreatedAt":"2025-10-28 16:34:00","video":"","vorDoi":"10.1186/s12884-026-08683-4","vorDoiUrl":"https://doi.org/10.1186/s12884-026-08683-4","workflowStages":[]},"version":"v1","identity":"rs-7908308","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7908308","identity":"rs-7908308","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}