Pregnancy outcomes in egg donation programs are similar when vitrified imported oocytes are compared to egg-sharing in a retrospective cohort study.  

Pregnancy outcomes in egg donation programs are similar when vitrified imported oocytes are compared to egg-sharing in a retrospective cohort study. | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Pregnancy outcomes in egg donation programs are similar when vitrified imported oocytes are compared to egg-sharing in a retrospective cohort study. Vanessa Devens Trindade, Marta Ribeiro Hentschke, Victoria Campos Dornelles, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5282943/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background : In the past decade, the use of donated oocytes has increased, with egg donation (ED) cycles accounting for nearly 10% of all assisted reproductive technology (ART) in the United States, with live birth rates exceeding 50% per cycle. Legal frameworks for ED vary across countries; for example, Brazil permits voluntary and shared donation but prohibits commercial donation, leading to imported egg-sharing programs. Despite the growing use of both fresh and vitrified oocytes, no studies have yet compared pregnancy rates between these different egg-sharing programs. Does the use of imported vitrified oocytes from an international bank result in similar pregnancy rates when compared to an egg-sharing donation with fresh oocytes? Methods : This study is a retrospective cohort including in vitro fertilization (IVF) cycles involving egg donation from January 2010 to December 2023. Patients were divided into two groups: those participating in the egg-sharing program and those receiving imported vitrified oocytes from an international bank. Results : A total of 391 patients were included, with 224 from egg-sharing group (comprising 251 IVF cycles) and 170 from the imported vitrified oocyte group (comprising 179 IVF cycles). The data between the groups were as follows, respectively: mature oocytes: 6.11±3.03, vs 6.88 ±1.69, p = 0.001; total embryos formed: 3.10±1.78, vs 3.26±1.73, p = 0.373, clinical pregnancy rate: 40.1%, vs 47.4%, p = 0.099, live birth and ongoing pregnancy rate: 30.7% vs 38%, p = 0.084, birth weight 2842±765 vs 3048± 547, p = 0.040, small for gestational age 21.6 vs 7.7%, p = 0.036. In the imported oocytes group, the pregnancy rates according to endometrial thickness were as follows: 12 mm 34.6%, p = 0.002. Conclusions : Egg recipient treatment using imported vitrified oocytes demonstrated similar laboratory outcomes and clinical pregnancy rates compared to the egg-sharing program. Additionally, recipients using vitrified oocytes achieved higher pregnancy rates when transfers were conducted with an endometrial thickness of 8-12 mm. Biological sciences/Biological techniques Biological sciences/Developmental biology Health sciences/Health care Health sciences/Medical research Oocyte Donation assisted reproduction techniques infertility gamete donation. Figures Figure 1 BACKGROUND In the last decade, the use of donated oocytes has increased. In the United States, oocyte donation cycles account for nearly 10% of all ART cycles, with live birth rates exceeding 50% per cycle [1]. Egg donation (ED) was first successfully used in assisted reproduction techniques (ART) in 1984 as an option for primary ovarian insufficiency (POI) [2]. Currently, the use of ED is indicated in situations where a woman cannot or should not use her own eggs. Some of the main indications include advanced maternal age, genetic conditions that could be passed on to her children and cannot be prevented by other techniques, diminished ovarian reserve, POI and previous oncological treatments [3]. Also, after repeated in vitro fertilization (IVF) failures for couples who have had multiple unsuccessful IVF attempts, and in cases of congenital absence of ovaries or ovaries removed for medical reasons, donor eggs can offer a significant chance of successful pregnancy [1,4,5]. There is a growing demand for treatments using ED, not only in the United States, but also in other countries [5]. This increase is motivated by several socioeconomic factors, such as the postponement of motherhood driven by personal projects – career advancement, financial goals – or social factors, such as the absence of a partner [6]. The legal status and compensation models of ED vary significantly between countries. In Brazil, donation cannot have commercial purposes, and donors are not allowed to know the identity of the recipients and vice versa. Voluntary donation of gametes is permitted, as is the shared donation of oocytes, in which the donor and recipient share both the biological material and the financial costs involved in the procedure. It is also allowed to use imported oocytes from international oocyte banks and to use eggs donated by a family member up to the fourth degree [7]. Determining which program is the most promising to offer patients is extremely important. However, to our knowledge, there are no studies that have compared the pregnancy rates between egg-sharing donation programs using fresh oocytes versus imported vitrified oocytes from international oocyte banks. Thus, the aim of the present study was to compare these two programs. We hypothesized that there is no difference in pregnancy rates between the groups. METHODS Study’s aim, design and setting The study’s main objective was to compare pregnancy rates between egg-sharing donation programs with fresh oocytes versus imported vitrified oocytes. For this purpose, a retrospective cohort study was performed at a Reproductive Medicine Center located in Porto Alegre, Rio Grande do Sul, Brazil, which is one of the major county’s centers. This study was conducted with guidance of Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline [8]. Study population This study included IVF cycles with oocyte donation performed between January 2010 and December 2023, as flowchart 1 . Patients included in the study chose ED due to previously failed cycles, advanced maternal age, POI or diminished ovarian reserves. They were mostly Caucasian, with completed higher education and high socioeconomic status. Inclusion Criteria Patients treated at Fertilitat – Center for Reproductive Medicine who underwent assisted reproductive treatment using either shared oocytes or oocytes from an international egg bank. Clinical data were collected after obtaining informed consent from all patients, as outlined in the regular center’s IVF protocol, allowing data for research. Exclusion Criteria Patients with frozen oocytes for egg-sharing and those who received oocytes donated by relatives up to the fourth degree were excluded from the study. The sample was divided into two groups for comparative analysis, according to their treatment decision: GROUP 1 - Egg-Sharing Donation Program (ESDP): Donors in the egg-sharing program were matched with their recipients based on phenotype and blood groups by clinicians. The number of oocytes obtained was dependent on the donor's response. GROUP 2 - Imported Vitrified Oocytes (IVO) from International Oocyte Bank: vitrified oocytes were shipped from Argentina’s WeBank to Brazil in a vapor-phase nitrogen dry shipper by a specialized courier. The temperature was continuously monitored by an electronic detector. Oocyte donors met the selection criteria outlined by Brazilian regulations and were matched with infertile couples based on their phenotype and blood groups. The number of oocytes obtained depended on how many oocytes the recipient purchased and the survival rate of the oocytes after thawing. Ovarian Stimulation Protocols in the Egg-Sharing Donation Program: All donors were healthy female volunteers under the age of 35 years, with normal karyotypes, who were screened and tested for infectious diseases and consented to anonymous donation. Controlled ovarian stimulation protocols are described elsewhere [5]. According to the program's rules, the total number of mature (metaphase II) oocytes was equally divided between donors and recipients; in the case of an odd number, the donor always had a preference. Between 2 to 4 hours after retrieval, the oocytes were inseminated by intracytoplasmic sperm injection (ICSI) using either husband or donor sperm. Warming of Vitrified Oocytes Imported from International Banks: The oocytes were warmed using a four-step dilution procedure. Briefly, the carrier device containing the oocytes was removed from the protective straw cap and dipped into a thawing solution at 37°C for equilibration. After 1 minute, the oocytes were placed in a diluent solution for 3 minutes. Subsequently, the oocytes were transferred to a washing solution for 5 minutes, followed by a final wash in the second well of the washing solution. The warmed oocytes were incubated for 2 hours before ICSI, using either husband or donor sperm. Embryo Culture - Both Programs: Embryos were cultured until transfer (days 3–7). Subsequently, embryo transfer, trophectoderm biopsy for Pre-Implantation Genetic Testing for Aneuploidy (PGTA), or cryopreservation at the blastocyst stage on days 5–7 was performed. PGTA was conducted using next-generation sequencing. Recipients’ Endometrial Preparation: In the Egg-Sharing Donation Program (ESDP), the cycles of the donor and recipient were synchronized using hormonal contraceptive pills to allow recipients to receive fresh embryos. For both groups, endometrial preparation was conducted with estrogen (4-8 mg of estradiol valerate daily) until a thick trilaminar endometrium was achieved. In women with an inadequate response to oral estrogen supplements, transdermal estrogen (6 mg of estradiol daily) was added. On the day of oocyte retrieval or the day of oocyte thawing, vaginal progesterone (600-800 mg of micronized progesterone daily) was initiated. Definitions: Clinical Pregnancy: Confirmation of pregnancy through ultrasound with visualization of the gestational sac. Live Birth and Ongoing Pregnancy: Pregnancies lasting more than 23 weeks that have progressed to childbirth, and viable pregnancies that are progressing beyond 20 weeks. Statistical Analysis: Patient demographic data were evaluated using descriptive statistics, which included information on means and frequencies. Continuous variables were compared using Student’s t-test, while frequencies were compared using Pearson's chi-squared test. Data analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 22 (IBM SPSS Software, USA), and significance was considered for p-values ≤ 0.05. The power to detect differences in clinical pregnancy rates between the groups was set at 80%. This value, adjusted for continuity correction, was determined using a significance level of 5%, with a sample size of 176 subjects in each group and clinical pregnancy rates of 45% for the importation group and 30% for the sharing group. This calculation was performed using the online Health Power and Sample Size for Health Researchers tool [9]. Ethics This study was approved by the Research Ethics Committee of Pontifical Catholic University of Rio Grande do Sul, protocol number 5.038.470, waving consent term for participants due to this study’s retrospective design. Nevertheless, an informed consent term was signed from all patients allowing data for further research, as outlined in the regular center’s IVF protocol. Furthermore, all authors signed a confidentiality responsibility term prior to the retrospective data collection. The methodology employed adhered to the guidelines and regulations set forth by Declaration of Helsinki. RESULTS A total of 391 patients were included in the study: 224 women in the ESDP group and 170 women in the Imported Vitrified Oocytes (IVO) group. Three patients underwent both treatments. The patients included in this study underwent a total of 430 IVF cycles. Clinical and laboratory data are summarized in Table 1. Table 1 - Clinical and Laboratory Data Egg-sharing donation program n=251 Imported vitrified oocytes n= 179 p Recipient age, years 43.3±4.6 42.8±4.3 0.258 a Semen* age, years 42.6±7.8 42.6±7.5 0.984 a Mature oocytes 6.11±3.03 6.88±1.69 0.001 a Inseminated oocytes** 5.98±2.91 6.88±1.69 <0.001 a Fertilized oocytes 4.73±2.57 5.37±1.94 0.001 a Fertilization rate total/number (%) 2143/2728(78.56) 955/1228(77.77) 0.309 b Semen concentration, number (%) 0.986 b Normal 210(83.7) 149(83.2) Oligospermia 24(9.6) 18(10.1) Severe oligospermia 17(6.8) 12(6.7) Semen origin, number (%) 0.316 b Ejaculated 239(95.2) 169(94.4) PESA; TESA 6(2.4) 2(1.1) Donor 6(2.4) 8(4.5) Embryos formed 3.10±1.78 3.26±1.73 0.373 a PGTA cycles, number (%) 11(4.4) 13(7.3) 0.200 b Euploid embryos, total/number (%) 19/33(57.58) 22/49(44.90) 0.368 b Fresh transfer, number (%) 177(70.5) 152(84.9) <0.001 b Legend: Data are presented as mean ± SD or total/number (%). *: age of the partner or donor; **: In some patients, not all oocytes received were inseminated. PESA: Percutaneous Epididymal Sperm Aspiration; TESA: Testicular Sperm Aspiration; PGTA: Pre-Implantation Genetic Testing. a - Student's t-test; b - Chi-square test. Patients underwent a total of 556 embryo transfers, with 322 in the ESDP group and 234 in the IVO group. Table 2 summarizes the transfer data. Table 2 - Embryo Transfer Data Egg-sharing donation program n= 322 Imported vitrified oocytes n=234 p Endometrium, total/number (%)* 0.687 b 12 mm 30/308(9.7) 26/218(11.9) Transfer of, number (%) FET 145(45) 82(35) 0.019 b Blastocyst 240(74.5) 234(100) <0.001 b SET 154(47.8) 209(89.3) <0.001 b PGTA 12(3.7) 8(3.4) 0.847 b Transferred embryos 1.56±0.57 1.10±0.30 <0.001 a Clinical Pregnancy, number (%) 129(40.1) 111 (47.4) 0.099 b Outcome, number (%) Live birth and ongoing 99(30.7) 89(38) 0.084 b Miscarriage 25(7.8) 20(8.5) 0.755 b Ectopic pregnancy 5(1.6) 2(0.9) 0.705 b Twin pregnancy, number (%) 13/99(12.1) 1/89(1.1) 0.003 b Legend: Data are presented as mean ± SD or total/number (%). *Measured on transfer day. FET: Frozen Embryo Transfer; SET: Single Embryo Transfer; PGTA: Pre-Implantation Genetic Testing for Aneuploidy. a - Student's t-test; b - Chi-square test. Considering only blastocyst transfers, the clinical pregnancy rate was 42.7% in the ESDP group. When excluding cleavage stage transfers, the cohort included 160 women in the ESDP group (171 IVF cycles and 239 embryo transfers) and 170 women in the IVO group (179 IVF cycles and 234 embryo transfers). The clinical pregnancy rates, live birth and ongoing pregnancy rates per IVF cycle when comparing ESDP and IVO were as follows: 59.6% (102/171) versus 62% (111/179), (p = 0.587) and 44.4% (76/171) versus 49.7% (89/179), (p = 0.287). The average number of transfers per cycle was 1.3 for both groups. The endometrial thickness was analyzed in relation to pregnancy rates, and these data are summarized in Table 3. Table 3 – Pregnancy Rates According to Endometrial Thickness Stratified by Groups Egg-sharing donation program Imported vitrified oocyte n nº % p n nº % p Endometrium 0.302 a 0.002 a 12 30 13 43.3 26 9 34.6 Legend: b - Chi-square test. The clinical pregnancy rate according to the woman's age was analyzed, dividing all patients into three groups: under 40 years, 40 to 44 years, and over 45 years. The pregnancy rates per woman by age were 50%, 45.3%, and 37.9%, respectively, with p = 0.094. Data relating to the obstetric outcomes are summarized in Table 4. In the ESDP group there were 97 live births over 23 weeks while the IVO group had 79 live births. Table 4 - Obstetric and Neonatal Outcomes Egg-sharing donation program Imported vitrified oocytes P Percentile, total/number (%) 0.036 b SGA 21/97(21.6) * 6/78(7.7) AGA 73/97(75.3) 68/78(87.2) LGA 3/97(3.1) 4/78(5.1) Gestational age, weeks 36.9± 3.0 37.4±1.7 0.168 a Birth weight, (Fetus 1), g 2842±765 3048± 547 0.040 a Birth weight, (Fetus 2), g 1866±566 2100** - Legend: Data are presented as mean ± SD or total/number (%). * Indicates that 8 (38%) were twins. ** Indicates one newborn. SGA = Small for Gestational Age; AGA = Appropriate for Gestational Age; LGA = Large for Gestational Age. a - Student's t-test; b - Chi-square test. A few clinical data were collected prospectively when importation began. These data are summarized below in Table 5. Table 5 - Clinical Data Presented by IVF Cycles Egg-sharing donation program n= 43 Imported vitrified oocytes n= 179 P Donor age, years 30.6±2.5 24.1±3.2 <0.001 a BMI recipient, kg/m2 25.1±4.0 23.4± 3.1 0.020 a BMI oocyte donor, kg/m2 24.4± 3.6 21.6±2.1 <0.001 a Previous IVF history, total/number (%) 30/40(75) 146/177(82.5) 0.271 b Number of previous IVF cycles 2.03±1.40 2.15±1.36 0.675 a Previous history,total/number (%) Menopause 8/39 (20.5) 12/163(7.4) 0.031 b Smoking 1/40(2.6) 6/170(3.5) 0.781 b Endometriosis 9/40(22.5) 36/174(20.7) 0.830 b Adenomiosis 7/40(17.5) 39/172(22.7) 0.531 b Hipotiroidism 8/40(20) 25/172(14.5) 0.467 b High blood pressure 1/40(2.5) 12/172(7) 0.470 b Psychiatric disease 3/40(7.5) 22/172(12.8) 0.427 b Nulliparous 19/40(47.5) 86/173(49.7) 0.862 b Previous Miscarriage 13/40(32.5) 60/173(34.7) 0.855 b Previous Ectopic Pregnancy 1/40(2.5) 10/173(5.8) 0.694 b Previous live birth 10/40(25) 25/173(14.5) 0.153 b Legend: Data are presented as mean ± SD or total/number (%). BMI = Body Mass Index. Values are presented as mean ± standard deviation or percentage. 1 - Student's t-test; 2 - Chi-square test. When n differs from the absolute number, it is indicated in parentheses. Data related to obstetric outcomes are summarized in Table 6. Table 6 - Obstetric and Neonatal Outcomes Outcomes, total/number (%) Egg-sharing donation program n= 18 Imported vitrified oocytes n=79 p Gestational hypertension 4/18(22.2) 12/78(15.4) 0.492 b Preeclampsia 2/18(11.1) 10/78(12.8) 0.843 b Gestational Diabetes Mellitus 5/18(27.8) 10/78(12.8) 0.148 b Neonatal ICU 2/18(11.1) 4/78 (5.1) 0.313 b Legend: Data are presented as total/number (%). ICU = Intensive Care Unit. b = Chi-square test. We also analyzed additional data in the prospective cohort since 2021, comparing the ESDP and IVO groups. The following data were reported: mean number of mature oocytes was 8.26 ± 3.25 vs. 6.88 ± 1.69, p < 0.001; clinical pregnancy rate was 41.2% (28/68) vs. 47.4% (111/234), p = 0.408; and live birth and ongoing pregnancy rate was 27.9% (19/68) vs. 38% (89/234), p = 0.151. DISCUSSION The analysis comparing the two-egg donation (ED) programs, egg-sharing and imported vitrified oocytes, suggested similar results. At the reproductive medicine center involved in this study, treatments using imported vitrified oocytes from international oocyte banks were initiated in 2021. Between 2021 and 2023, we imported 1,230 oocytes. Before 2021, the only option for treatments involving ED was egg-sharing. Data from the Report of the National Embryo Production System reveal that 3,754 clinical pregnancies were achieved with the help of ED from 2020 to 2023 in Brazil (923 from fresh oocytes and 2,831 from frozen oocytes) [10]. This reflects the growing demand for ED treatments in our country. This trend is not only evident in Brazil but also in other countries [5]. It is motivated by various socioeconomic factors, such as delays in childbearing and increases in the age of first pregnancy [6]. The high demand for ED leads to a search for new treatment alternatives, considering that egg-sharing relies on the availability of donors, which remains limited [11]. In this context, IVO from international oocyte banks has become an important alternative. Below, we discuss the main findings of this study. Clinical and Laboratory Data In the IVO group we noted a significantly higher number of mature, inseminated, and fertilized oocytes. This can be attributed to two factors: first, in the egg-sharing program, we rely on donor response to ovarian stimulation. Second, in the IVO group, recipients can choose how many mature oocytes they wish to import, and the thawing survival rate was 93%. An observational study from Cobo et al. , 2015, reported a survival rate of 90.4% in a donation program involving vitrified oocytes and another study, from Greco et a l, 2022, reported an 88.2% oocyte survival rate for imported oocytes [12, 13]. Our oocyte survival rate was comparable. Laboratory results from our study suggest that vitrified oocytes subjected to international transport yield similar laboratory results as fresh donated oocytes, reinforcing this viable option as a reproductive medicine treatment. We observed a higher rate of fresh embryo transfers in the IVO group. In our practice, ESDP recipients synchronize their menstrual cycles with their donor to facilitate fresh embryo transfer. The recipient prepares the endometrium while the donor undergoes ovarian stimulation. However, it is not uncommon for the endometrium not to respond adequately, necessitating a freeze-all approach in such cases. In the IVO cycle, thawing oocytes is only authorized after ensuring adequate endometrial preparation, which explains the higher rates of fresh embryo transfers in this group. According to recent meta-analysis data, a freeze-all strategy does not impair pregnancy chances [14]; however, it does increase treatment costs for patients. Regarding patients' medical history, the majority had already attempted an average of two IVF cycles prior to seeking egg donation, indicating the emotional process of elaboration and mourning associated with giving up genetic capital [15]. In the context of Pre-Implantation Genetic Testing for Aneuploidy (PGTA) cycles, it is important to highlight the high percentage found in this study. In Brazil, patients can legally choose whether to undergo PGTA, which may reflect their desire to increase clinical pregnancy chances considering past treatment failures and to gain more information about the embryos, given that the donor remains unknown to them. However, it is crucial to consider previous studies indicating that PGTA does not improve clinical outcomes in cycles utilizing donor oocytes compared to those without PGTA [16, 17]. Furthermore, a recent study published in 2024 showed poorer outcomes for PGTA in fresh oocyte donation cycles, including lower live birth rates and cumulative live birth rates [18]. Thus, current evidence suggests that performing PGTA on embryos derived from oocyte donors may have limited benefits; its application should be carefully evaluated, considering the additional treatment costs and time required without clear improvements in clinical outcomes, and it may even lead to poorer outcomes in some contexts. An interesting finding is that the mean number of mature oocytes has changed in recent years: when we analyzed data from 2021 onwards, the ESDP group had a statistically significant higher number of mature oocytes. Since we began importing oocytes and offering another treatment option, the selection criteria for donors have become more stringent, with the egg-sharing program now accepting only patients with excellent ovarian reserves. This more careful selection process has been associated with the increased number of mature oocytes observed in the egg-sharing program after 2021. Embryo Transfer Data There were more blastocyst transfers in the IVO group. This data highlights the evolution ofbART, with a reduction in cleavage stage transfers. The data for the ESDP were collected from 2010 to 2023, while importation began in 2021. Currently, the transfer and vitrification of blastocysts are widely recommended [19]. This shift is associated with higher rates of clinical pregnancy, as demonstrated in a 2015 study that showed significantly higher pregnancy rates when comparing blastocyst transfers with cleavage stage transfers (43.1% vs. 24%, p = 0.041) [20]. Moreover, current evidence suggests there is no difference in blastocyst formation rates when comparing embryos created from fresh versus vitrified donated oocytes [21, 22]. Another interesting aspect is the trend toward single embryo transfer (SET). Brazilian legislation currently permits the transfer of a maximum of two embryos during egg donation [7], whereas this number was higher according to previous regulations. Results indicated that only half of the transfers in the ESDP group were SET, and both the average number of embryos transferred, and the percentage of twin pregnancies were higher in the ESDP group. It is well-known that twin pregnancies are associated with higher rates of obstetric complications, such as hypertension, pre-eclampsia, premature birth, and increased risks of neonatal complications, including lower birth weight and respiratory distress syndrome, as well as psychological, social, and financial challenges for families [23]. Therefore, we must always inform patients about the heightened obstetric risks associated with twin pregnancies before proceeding with the transfer of two embryos. Clinical Pregnancy Rate Clinical pregnancy, live birth and ongoing pregnancy rates were similar between the two groups. Rates of miscarriage and ectopic pregnancy were also comparable. A study evaluating clinical pregnancy rates between oocyte donation using vitrified oocytes and fresh cycles reported similar findings, with a clinical pregnancy rate of 60.9% in the fresh group and 59.0% in the vitrified group (p = 0.771) [21]. A factor found to be associated with lower clinical pregnancy rates was the endometrial thickness in the IVO group. There is extensive literature highlighting the importance of endometrium in embryo transfer [24, 25, 26, 27]. In our study, higher clinical pregnancy rates in the IVO group were associated with endometrial thickness measurements between 8-12 mm on transfer day. The cumulative pregnancy rate per IVF cycle was similar between the groups and within expected ranges. A study on vitrified egg donation reported a clinical pregnancy rate of 48.4% per donation cycle [12]. Additionally, Ermanno Greco et al . reported a clinical pregnancy rate of 51.8% with imported vitrified oocytes [13]. Finally, there was no statistically significant difference in clinical pregnancy rates when the analyses were performed by separating women into age groups. However, the data indicated a tendency towards lower pregnancy rates for women over 45 years old. Jason S. Yeh et al reported similar findings, showing lower clinical pregnancy rates in recipients older than 45 years (45-49 years old: OR 0.92, 95% CI: 0.86–0.98; p = 0.01; ≥50 years old: OR 0.81, 95% CI: 0.71–0.93; p = 0.002) [28]. Similarly, Campos et al., 2008 , reported that recipients older than 38 years old had lower pregnancy and implantation rates, suggesting that age may be an important factor for uterine receptivity, regardless of the age of the oocytes [29]. Obstetric Outcomes The incidence of gestational diabetes mellitus (GDM) was higher in the ESDP group, although this difference was not statistically significant. The recipients in the ESDP group had higher body mass indexes (BMIs), which could explain the increased incidence of GDM in this group. The prevalence of GDM in the general population varies from 1.4% to 6.1% [30]. In the present study, the incidence was 27.8% in ESDP and 12.8% in the IVO group. A study evaluating the impact of the health of recipients with obstetric comorbidities observed an incidence of 28% of GDM in women over 40 years of age, compared to 4% in women under 39 years, suggesting that age significantly affects these statistics [31]. Currently, several studies associate higher risks of preeclampsia and hypertension with any form of ART [32, 33, 34]. Moreover, some research has indicated even higher rates of hypertensive disorders associated with donated oocytes [35, 36, 37]. Consistent with these findings, we observed a high incidence of gestational hypertension and preeclampsia in both groups analyzed. It is essential to inform egg recipients about these increased risks for developing pregnancy-related comorbidities and to ensure they are referred to high-risk pregnancy prenatal care for appropriate follow-up. Birth Weight and Percentile The IVO group was associated with higher birth weights compared to the ESDP group; however, most newborns in both groups were classified as appropriate for gestational age (AGA). In contrast, the ESDP was associated with higher rates of small for gestational age (SGA) infants. This discrepancy could be attributed to the higher rate of twin pregnancies in the ESDP group, even though only 38% of SGA newborns were twins. Previous studies have demonstrated similar findings, with a meta-analysis from 2016 showing that the risk of SGA was nearly twice as likely in ED pregnancies compared to autologous IVF pregnancies (OR 1.81, 95% CI 1.26–2.60) (OR 1.81, 95% CI 1.26–2.60) [38]. Study’s limitations The main limitation of this study was its retrospective nature. Additionally, various strategies (such as laboratory protocols, laboratory environment, methods of embryo culture, form of embryo and gamete manipulation) have been employed since 2010, and new technologies have been incorporated over time. CONCLUSION In conclusion, both treatments exhibited similar clinical pregnancy rates. This indicates that imported vitrified oocytes yield outcomes comparable to those of the Egg-Sharing Donation Program, which plays an important role in ED treatments. It is crucial to pay attention to endometrial thickness in recipients prior to embryo transfer; specifically, an endometrial thickness of 8-12 mm was associated with higher clinical pregnancy rates among patients using imported oocytes. Furthermore, recipients should be counseled about the increased risks of obstetric comorbidities compared to the general population. Abbreviations Egg Donation (ED) Assisted Reproduction Techniques (ART) Primary Ovarian Insufficiency (POI) In Vitro Fertilization (IVF) Egg-Sharing Donation Program (ESDP) Imported Vitrified Oocytes (IVO) Intracytoplasmic Sperm Injection (ICSI) Pre-Implantation Genetic Testing for Aneuploidy (PGTA) Declarations Ethics approval and consent to participate This study was approved by the Research Ethics Committee of Pontifical Catholic University of Rio Grande do Sul, protocol number 5.038.470, waving consent term for participants due to this study’s retrospective design. Nevertheless, an informed consent term was signed from all patients allowing data for further research, as outlined in the regular center’s IVF protocol. Furthermore, all authors signed a confidentiality responsibility term prior to the retrospective data collection. The methodology employed adhered to the guidelines and regulations set forth by Declaration of Helsinki. Consent for publication Not applicable, since this study does not contain data from any individual person. Availability of data and materials To preserve confidential patient’s information, data are not openly available; However, it could be obtained upon reasonable requests in the ScienceDB repository on which all datasets generated and/or analyzed during the current study are available at following links: https://download.scidb.cn/download?fileId=a888646afc8e528883df1739684d7b47&path=/V1/retrospective.xlsx& [email protected] &fileName=retrospective%20.xlsx https://download.scidb.cn/download?fileId=22ec81306c0480ef3b53e01286e1cbc1&path=/V1/prospective.xlsx& [email protected] &fileName=prospective.xlsx. Competing interests All the authors declare no competing interests. Funding This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001. Authors’ contributions VDT and MRH performed the study design, collection of data, data analysis, manuscript drafting and critical discussion.VCD, IBT and NFV were involved incollection of data and manuscript drafting.TC participated in the study’s design definition, critical discussion of results and manuscript drafting. AP, CEPF and MB performedcritical discussion and final manuscript approval.All authors read and approved the final manuscript. Acknowledgements The authors would like to express their heartfelt gratitude to all the participating patients and the dedicated team involved in our oocyte donation program. References Melnick AP, Rosenwaks Z. Oocyte donation: insights gleaned and future challenges. Fertil Steril. 2018;110(6):988-93. Lutjen P, Trounson A, Leeton J, Findlay J, Wood C, Renou P. The establishment and maintenance of pregnancy using in vitro fertilization and embryo donation in a patient with primary ovarian failure. Nature. 1984;307(5947):174-5. Guidance regarding gamete and embryo donation. (2021) Fertil Steril. Bracewell-Milnes T, Hossain A, Jones BP, Faris R, Parikh J, Nicopoullos J, Johnson M, Thum MY. Does egg-sharing negatively impact on the chance of the donor or recipient achieving a live birth? Hum Fertil (Camb). 2023;26(2):266-75. Colombo T, Hentschke MR, Badalotti M, Kira ATF, Telöken IB, Trindade VD, Dornelles VC, Petracco A, Wendland EM. A sharing oocyte donation program: a 15-year cohort study. JBRA Assist Reprod. 2023;27(3):348-54. Braga DP, Setti AS, Figueira RC, Azevedo Mde C, Iaconelli A Jr, Lo Turco EG, Borges EJ Jr. Freeze-all, oocyte vitrification, or fresh embryo transfer? Lessons from an egg-sharing donation program. Fertil Steril. 2016;106(3):615-22. Conselho Federal de Medicina. Resolução CFM nº 2.294, de 27 de maio de 2021. Diário Oficial da União; 2021. The Vienna consensus: report of an expert meeting on the development of ART laboratory performance indicators. Reprod BioMed Online. 2017;35(5):494–510. PSS Health: Power and Sample Size for Health Researchers. Available at: https://hcpa-unidade-bioestatistica.shinyapps.io/PSS_Health. Accessed Jun 2024. ANVISA. SisEmbrio - Relatório do Sistema Nacional de Produção de Embriões. Available at: https://www.gov.br/anvisa/pt-br/acessoainformacao/dadosabertos/informacoes-analiticas/sisembrio. Accessed 2024. Braga D, Setti AS, Iaconelli A Jr, Borges E Jr. Predictive factors for successful pregnancy in an egg-sharing donation program. JBRA Assist Reprod. 2020;24(2):163-9. Cobo A, Garrido N, Pellicer A, Remohí J. Six years' experience in ovum donation using vitrified oocytes: report of cumulative outcomes, impact of storage time, and development of a predictive model for oocyte survival rate. Fertil Steril. 2015;104(6):1426-34.e1-8. Greco E, Donno V, Greco A, Minasi MG, Pristerà A, Pirastu G, et al. Which factors influence the success rate of egg donation programmes with imported vitrified oocytes? Reprod Biomed Online. 2022;45(2):264-73. Zaat T, Zagers M, Mol F, Goddijn M, van Wely M, Mastenbroek S. Fresh versus frozen embryo transfers in assisted reproduction. Cochrane Database Syst Rev. 2021;2(2) Lasheras G, Mestre-Bach G, Clua E, Rodríguez I, Farré-Sender B. Cross-Border Reproductive Care: Psychological Distress in A Sample of Women Undergoing In Vitro Fertilization Treatment with and without Oocyte Donation. Int J Fertil Steril. 2020;14(2):129-35. Masbou AK, Friedenthal JB, McCulloh DH, McCaffrey C, Fino ME, Grifo JA, Licciardi F. A Comparison of Pregnancy Outcomes in Patients Undergoing Donor Egg Single Embryo Transfers With and Without Preimplantation Genetic Testing. Reprod Sci. 2019;26(12):1661-5. Doyle N, Gainty M, Eubanks A, Doyle J, Hayes H, Tucker M, et al. Donor oocyte recipients do not benefit from preimplantation genetic testing for aneuploidy to improve pregnancy outcomes. Hum Reprod. 2020;35(11):2548-55. Gingold JA, Kucherov A, Wu H, Fazzari M, Lieman H, Ball GD, et al. PGT-A is Associated with Reduced Live Birth Rates in Fresh but not Frozen Donor Oocyte IVF cycles: An Analysis of 18,562 Donor Cycles Reported to SART CORS. Fertil Steril. 2024. Glujovsky D, Quinteiro Retamar AM, Alvarez Sedo CR, Ciapponi A, Cornelisse S, Blake D. Cleavage-stage versus blastocyst-stage embryo transfer in assisted reproductive technology. Cochrane Database Syst Rev. 2022;5(5) Fernández-Shaw S, Cercas R, Braña C, Villas C, Pons I. Ongoing and cumulative pregnancy rate after cleavage-stage versus blastocyst-stage embryo transfer using vitrification for cryopreservation: impact of age on the results. J Assist Reprod Genet. 2015;32(2):177-84. Domingues TS, Aquino AP, Barros B, Mazetto R, Nicolielo M, Kimati CM, et al. Egg donation of vitrified oocytes bank produces similar pregnancy rates by blastocyst transfer when compared to fresh cycle. J Assist Reprod Genet. 2017;34(11):1553-7. García JI, Noriega-Portella L, Noriega-Hoces L. Efficacy of oocyte vitrification combined with blastocyst stage transfer in an egg donation program. Hum Reprod. 2011;26(4):782-90. Gerris JM. Single embryo transfer and IVF/ICSI outcome: a balanced appraisal. Hum Reprod Update. 2005;11(2):105-21. Dain L, Bider D, Levron J, Zinchenko V, Westler S, Dirnfeld M. Thin endometrium in donor oocyte recipients: enigma or obstacle for implantation? Fertil Steril. 2013;100(5):1289-95. Vartanyan E, Tsaturova K, Devyatova E. Thin endometrium problem in IVF programs. Gynecol Endocrinol. 2020;36(sup1):24-7. Liu KE, Hartman M, Hartman A, Luo ZC, Mahutte N. The impact of a thin endometrial lining on fresh and frozen-thaw IVF outcomes: an analysis of over 40 000 embryo transfers. Hum Reprod. 2018;33(10):1883-8. Gallos ID, Khairy M, Chu J, Rajkhowa M, Tobias A, Campbell A, et al. Optimal endometrial thickness to maximize live births and minimize pregnancy losses: Analysis of 25,767 fresh embryo transfers. Reprod Biomed Online. 2018;37(5):542-8. Yeh JS, Steward RG, Dude AM, Shah AA, Goldfarb JM, Muasher SJ. Pregnancy outcomes decline in recipients over age 44: an analysis of 27,959 fresh donor oocyte in vitro fertilization cycles from the Society for Assisted Reproductive Technology. Fertil Steril. 2014;101(5):1331-6. Campos I, Gómez E, Fernández-Valencia AL, Landeras J, González R, Coy P, et al. Effects of men and recipients' age on the reproductive outcome of an oocyte donation program. J Assist Reprod Genet. 2008;25(9-10):445-52. Brody SC, Harris R, Lohr K. Screening for gestational diabetes: a summary of the evidence for the U.S. Preventive Services Task Force. Obstet Gynecol. 2003;101:380-92. doi:10.1016/s0029-7844(02)03057-0. Michalas S, Loutradis D, Drakakis P, Milingos S, Papageorgiou J, Kallianidis K, et al. Oocyte donation to women over 40 years of age: pregnancy complications. Eur J Obstet Gynecol Reprod Biol. 1996;64(2):175-8. doi:10.1016/0028-2243(96)02693-3. Yadav V, Bakolia P, Malhotra N, Mahey R, Singh N, Kriplani A. Comparison of obstetric outcomes of pregnancies after donor-oocyte in vitro fertilization and self-oocyte in vitro fertilization: A retrospective cohort study. J Hum Reprod Sci. 2018;11(4):370-5. Almasi-Hashiani A, Omani-Samani R, Mohammadi M, Amini P, Navid B, Alizadeh A, et al. Assisted reproductive technology and the risk of preeclampsia: an updated systematic review and meta-analysis. BMC Pregnancy Childbirth. 2019;19(1):149. Kornfield MS, Gurley SB, Vrooman LA. Increased risk of preeclampsia with assisted reproductive technologies. Curr Hypertens Rep. 2023;25(9):251-61. Rodriguez-Wallberg KA, Berger AS, Fagerberg A, Olofsson JI, Scherman-Pukk C, Lindqvist PG, et al. Increased incidence of obstetric and perinatal complications in pregnancies achieved using donor oocytes and single embryo transfer in young and healthy women. A prospective hospital-based matched cohort study. Gynecol Endocrinol. 2019;35(4):314-9. Levron Y, Dviri M, Segol I, Yerushalmi GM, Hourvitz A, Orvieto R, et al. The 'immunologic theory' of preeclampsia revisited: a lesson from donor oocyte gestations. Am J Obstet Gynecol. 2014;211(4):383.e1-5. Blázquez A, García D, Rodríguez A, Vassena R, Figueras F, Vernaeve V. Is oocyte donation a risk factor for preeclampsia? A systematic review and meta-analysis. J Assist Reprod Genet. 2016;33(7):855-63. Jeve YB, Potdar N, Opoku A, Khare M. Donor oocyte conception and pregnancy complications: a systematic review and meta-analysis. Bjog. 2016;123(9):1471-80. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. 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","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eIn the last decade, the use of donated oocytes has increased. In the United States, oocyte donation cycles account for nearly 10% of all ART cycles, with live birth rates\u0026nbsp;exceeding\u0026nbsp;50% per cycle [1]. \u0026nbsp; Egg donation (ED) was first successfully used in assisted reproduction techniques (ART) in 1984 as an option for primary ovarian insufficiency (POI) [2]. Currently, the use of ED is indicated in situations where a woman cannot or should not use her own eggs. Some of the main indications include advanced maternal age, genetic conditions that could be passed on to her children and cannot be prevented by other techniques, diminished ovarian reserve, POI and previous oncological treatments [3]. Also, after repeated in vitro fertilization (IVF) failures for couples who have had multiple unsuccessful IVF attempts, and in cases of congenital absence of ovaries or ovaries removed for medical reasons, donor eggs can offer a significant chance of successful pregnancy\u0026nbsp;[1,4,5]. There is a growing demand for treatments using ED, not only in the United States, but also in other countries [5]. This increase is motivated by several socioeconomic factors, such as the postponement of motherhood driven by personal projects – career advancement, financial goals – or social\u0026nbsp;factors, such as the absence of a partner [6].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe legal status and compensation models of ED vary significantly between countries. In Brazil, donation cannot have commercial purposes, and donors are not allowed to know the identity of the recipients and vice versa. Voluntary donation of gametes is permitted, as is the shared donation of oocytes, in which the donor and recipient share both the biological material and the financial costs involved in the procedure. It is also allowed to use imported oocytes from international oocyte banks and to use eggs donated by a family member up to the fourth degree [7]. \u0026nbsp;Determining which program is the most promising to offer patients is extremely important. However, to our knowledge, there are no studies that have compared the pregnancy rates between egg-sharing donation programs using fresh oocytes versus imported vitrified oocytes from international oocyte banks. Thus, the aim of the present study was to compare these two programs. We hypothesized that there is no difference in pregnancy rates between the groups.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003e\u003cstrong\u003eStudy\u0026rsquo;s aim, design and setting \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study\u0026rsquo;s main objective was to compare\u0026nbsp;pregnancy rates between egg-sharing donation programs with fresh oocytes versus imported vitrified oocytes. For this purpose,\u0026nbsp;a retrospective cohort study was performed at a Reproductive Medicine Center located in Porto Alegre, Rio Grande do Sul, Brazil, which is one of the major county\u0026rsquo;s centers. This study was conducted with guidance of Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline [8].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy population \u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study included IVF cycles with oocyte donation performed between January 2010 and December 2023, as \u003cstrong\u003e\u003cu\u003eflowchart 1\u003c/u\u003e\u003c/strong\u003e. Patients included in the study chose ED due to previously failed cycles, advanced maternal age, POI or diminished ovarian reserves. They were mostly Caucasian, with completed higher education and high socioeconomic status.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients treated at Fertilitat \u0026ndash; Center for Reproductive Medicine who underwent assisted reproductive treatment using either shared oocytes or oocytes from an international egg bank. Clinical data were collected after obtaining informed consent from all patients, as outlined in the regular center\u0026rsquo;s IVF protocol, allowing data for research.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatients with frozen oocytes for egg-sharing and those who received oocytes donated by relatives up to the fourth degree were excluded from the study.\u003c/p\u003e\n\u003cp\u003eThe sample was divided into two groups for comparative analysis, according to their treatment decision:\u003c/p\u003e\n\u003col start=\"1\" type=\"1\"\u003e\n \u003cli\u003e\u003cstrong\u003eGROUP 1 - Egg-Sharing Donation Program (ESDP): Donors\u003c/strong\u003e in the egg-sharing program were matched with their recipients based on phenotype and blood groups by clinicians. The number of oocytes obtained was dependent on the donor\u0026apos;s response.\u003c/li\u003e\n\u003c/ol\u003e\n\u003col start=\"2\" type=\"1\"\u003e\n \u003cli\u003e\u003cstrong\u003eGROUP 2 - Imported Vitrified Oocytes (IVO) from International Oocyte Bank:\u003c/strong\u003e vitrified oocytes were shipped from Argentina\u0026rsquo;s WeBank to Brazil in a vapor-phase nitrogen dry shipper by a specialized courier. The temperature was continuously monitored by an electronic detector. Oocyte donors met the selection criteria outlined by Brazilian regulations and were matched with infertile couples based on their phenotype and blood groups. The number of oocytes obtained depended on how many oocytes the recipient purchased and the survival rate of the oocytes after thawing.\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e\u003cstrong\u003eOvarian Stimulation Protocols in the Egg-Sharing Donation Program:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll donors were healthy female volunteers under the age of 35 years, with normal karyotypes, who were screened and tested for infectious diseases and consented to anonymous donation. Controlled ovarian stimulation protocols are described elsewhere [5]. According to the program\u0026apos;s rules, the total number of mature (metaphase II) oocytes was equally divided between donors and recipients; in the case of an odd number, the donor always had a preference. Between 2 to 4 hours after retrieval, the oocytes were inseminated by intracytoplasmic sperm injection (ICSI) using either husband or donor sperm.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWarming of Vitrified Oocytes Imported from International Banks:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe oocytes were warmed using a four-step dilution procedure. Briefly, the carrier device containing the oocytes was removed from the protective straw cap and dipped into a thawing solution at 37\u0026deg;C for equilibration. After 1 minute, the oocytes were placed in a diluent solution for 3 minutes. Subsequently, the oocytes were transferred to a washing solution for 5 minutes, followed by a final wash in the second well of the washing solution. The warmed oocytes were incubated for 2 hours before ICSI, using either husband or donor sperm.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmbryo Culture - Both Programs:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEmbryos were cultured until transfer (days 3\u0026ndash;7). Subsequently, embryo transfer, trophectoderm biopsy for Pre-Implantation Genetic Testing for Aneuploidy (PGTA), or cryopreservation at the blastocyst stage on days 5\u0026ndash;7 was performed. PGTA was conducted using next-generation sequencing.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecipients\u0026rsquo; Endometrial Preparation:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the Egg-Sharing Donation Program (ESDP), the cycles of the donor and recipient were synchronized using hormonal contraceptive pills to allow recipients to receive fresh embryos. For both groups, endometrial preparation was conducted with estrogen (4-8 mg of estradiol valerate daily) until a thick trilaminar endometrium was achieved. In women with an inadequate response to oral estrogen supplements, transdermal estrogen (6 mg of estradiol daily) was added. On the day of oocyte retrieval or the day of oocyte thawing, vaginal progesterone (600-800 mg of micronized progesterone daily) was initiated.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDefinitions:\u003c/strong\u003e \u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eClinical Pregnancy:\u0026nbsp;\u003c/strong\u003eConfirmation of pregnancy through ultrasound with visualization of the gestational sac.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eLive Birth and Ongoing Pregnancy:\u003c/strong\u003e Pregnancies lasting more than 23 weeks that have progressed to childbirth, and viable pregnancies that are progressing beyond 20 weeks.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical Analysis:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePatient demographic data were evaluated using descriptive statistics, which included information on means and frequencies. Continuous variables were compared using Student\u0026rsquo;s t-test, while frequencies were compared using Pearson\u0026apos;s chi-squared test. Data analyses were performed using the Statistical Package for the Social Sciences (SPSS) version 22 (IBM SPSS Software, USA), and significance was considered for p-values \u0026le; 0.05. The power to detect differences in clinical pregnancy rates between the groups was set at 80%. This value, adjusted for continuity correction, was determined using a significance level of 5%, with a sample size of 176 subjects in each group and clinical pregnancy rates of 45% for the importation group and 30% for the sharing group. This calculation was performed using the online Health Power and Sample Size for Health Researchers tool [9].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Research Ethics Committee of Pontifical Catholic University of Rio Grande do Sul, protocol number 5.038.470, waving consent term for participants due to this study\u0026rsquo;s retrospective design. Nevertheless, an informed consent term was signed from all patients allowing data for further research, as outlined in the regular center\u0026rsquo;s IVF protocol. Furthermore, all authors signed a confidentiality responsibility term prior to the retrospective data collection. The methodology employed adhered to the guidelines and regulations set forth by Declaration of Helsinki.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003eA total of 391 patients were included in the study: 224 women in the ESDP group and 170 women in the Imported Vitrified Oocytes (IVO) group. Three patients underwent both treatments. The patients included in this study underwent a total of 430 IVF cycles. Clinical and laboratory data are summarized in Table 1.\u003c/p\u003e\n\u003cp\u003eTable 1 - Clinical and Laboratory Data\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003eEgg-sharing donation\u003c/p\u003e\n \u003cp\u003eprogram\u003c/p\u003e\n \u003cp\u003en=251\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003eImported vitrified oocytes\u003c/p\u003e\n \u003cp\u003en= 179\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eRecipient age, years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e43.3\u0026plusmn;4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e42.8\u0026plusmn;4.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.258\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eSemen* age, years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e42.6\u0026plusmn;7.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e42.6\u0026plusmn;7.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.984\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eMature oocytes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e6.11\u0026plusmn;3.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e6.88\u0026plusmn;1.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eInseminated oocytes**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e5.98\u0026plusmn;2.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e6.88\u0026plusmn;1.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eFertilized oocytes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e4.73\u0026plusmn;2.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e5.37\u0026plusmn;1.94\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.001\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eFertilization rate\u003c/p\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp;total/number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e2143/2728(78.56)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e955/1228(77.77)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.309\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 265px;\"\u003e\n \u003cp\u003eSemen concentration, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 265px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.986\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Normal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e210(83.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e149(83.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Oligospermia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e24(9.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e18(10.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Severe oligospermia\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e17(6.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e12(6.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"4\" valign=\"top\" style=\"width: 530px;\"\u003e\n \u003cp\u003eSemen origin, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.316\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Ejaculated\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e239(95.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e169(94.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; PESA; TESA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e6(2.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e2(1.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; Donor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e6(2.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e8(4.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eEmbryos formed\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e3.10\u0026plusmn;1.78\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e3.26\u0026plusmn;1.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.373\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003ePGTA cycles, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e11(4.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e13(7.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.200\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eEuploid embryos, total/number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e19/33(57.58)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e22/49(44.90)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e0.368\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 255px;\"\u003e\n \u003cp\u003eFresh transfer, number (%)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 142px;\"\u003e\n \u003cp\u003e177(70.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 133px;\"\u003e\n \u003cp\u003e152(84.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 75px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eLegend: Data are presented as mean \u0026plusmn; SD or total/number (%). \u0026nbsp;*: age of the partner or donor; **: In some patients, not all oocytes received were inseminated. PESA: Percutaneous Epididymal Sperm Aspiration; TESA: Testicular Sperm Aspiration; PGTA: Pre-Implantation Genetic Testing. a - Student\u0026apos;s t-test; b - Chi-square test.\u003c/p\u003e\n\u003cp\u003ePatients underwent a total of 556 embryo transfers, with 322 in the ESDP group and 234 in the IVO group. Table 2 summarizes the transfer data.\u003c/p\u003e\n\u003cp\u003eTable 2 - Embryo Transfer Data\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003eEgg-sharing\u003c/p\u003e\n \u003cp\u003edonation program\u003c/p\u003e\n \u003cp\u003en= 322\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003eImported vitrified oocytes\u003c/p\u003e\n \u003cp\u003en=234\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 521px;\"\u003e\n \u003cp\u003eEndometrium, total/number (%)*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.687\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026lt;8 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e46/308(14.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e34/218(15.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp;8-12 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e232/308(75.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e158/218(72.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 52px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026gt;12 mm\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e30/308(9.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e26/218(11.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 31px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eTransfer of, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eFET\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e145(45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e82(35)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.019\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eBlastocyst\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e240(74.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e234(100)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eSET\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e154(47.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e209(89.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003ePGTA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e12(3.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e8(3.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.847\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eTransferred embryos\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e1.56\u0026plusmn;0.57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e1.10\u0026plusmn;0.30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eClinical Pregnancy, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e129(40.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e111 (47.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.099\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eOutcome, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eLive birth and ongoing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e99(30.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e89(38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.084\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eMiscarriage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e25(7.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e20(8.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.755\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eEctopic pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e5(1.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e2(0.9)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.705\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eTwin pregnancy, number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 123px;\"\u003e\n \u003cp\u003e13/99(12.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 125px;\"\u003e\n \u003cp\u003e1/89(1.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.003\u003csup\u003eb\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eLegend: Data are presented as mean \u0026plusmn; SD or total/number (%). *Measured on transfer day. FET: Frozen Embryo Transfer; SET: Single Embryo Transfer; PGTA: Pre-Implantation Genetic Testing for Aneuploidy. a - Student\u0026apos;s t-test; b - Chi-square test.\u003c/p\u003e\n\u003cp\u003eConsidering only blastocyst transfers, the clinical pregnancy rate was 42.7% in the ESDP group. When excluding cleavage stage transfers, the cohort included 160 women in the ESDP group (171 IVF cycles and 239 embryo transfers) and 170 women in the IVO group (179 IVF cycles and 234 embryo transfers). The clinical pregnancy rates, live birth and ongoing pregnancy rates per IVF cycle when comparing ESDP and IVO were as follows: 59.6% (102/171) versus 62% (111/179), (p = 0.587) and 44.4% (76/171) versus 49.7% (89/179), (p = 0.287). The average number of transfers per cycle was 1.3 for both groups. The endometrial thickness was analyzed in relation to pregnancy rates, and these data are summarized in Table 3.\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"10\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003eTable 3 \u0026ndash; Pregnancy Rates According to Endometrial Thickness Stratified by Groups\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 18.5124%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"top\" style=\"width: 37.1901%;\"\u003e\n \u003cp\u003eEgg-sharing donation program\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 3.80165%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"top\" style=\"width: 40.4959%;\"\u003e\n \u003cp\u003eImported vitrified oocyte\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 18.5124%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003en\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 7.60331%;\"\u003e\n \u003cp\u003en\u0026ordm;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.92562%;\"\u003e\n \u003cp\u003e%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.9091%;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 3.80165%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003en\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.26446%;\"\u003e\n \u003cp\u003en\u0026ordm;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.7438%;\"\u003e\n \u003cp\u003e%\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.7355%;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 18.5124%;\"\u003e\n \u003cp\u003eEndometrium\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 7.60331%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.92562%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.9091%;\"\u003e\n \u003cp\u003e0.302\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 3.80165%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.26446%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.7438%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.7355%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.002\u003csup\u003ea\u003c/sup\u003e\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 18.5124%;\"\u003e\n \u003cp\u003e\u0026lt; 8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 7.60331%;\"\u003e\n \u003cp\u003e14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.92562%;\"\u003e\n \u003cp\u003e30.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.9091%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 3.80165%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.26446%;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.7438%;\"\u003e\n \u003cp\u003e23.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.7355%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 18.5124%;\"\u003e\n \u003cp\u003e8 \u0026ndash; 12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e232\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 7.60331%;\"\u003e\n \u003cp\u003e98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.92562%;\"\u003e\n \u003cp\u003e42.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.9091%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 3.80165%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e158\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.26446%;\"\u003e\n \u003cp\u003e85\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.7438%;\"\u003e\n \u003cp\u003e53.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.7355%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 18.5124%;\"\u003e\n \u003cp\u003e\u0026gt; 12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 7.60331%;\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.92562%;\"\u003e\n \u003cp\u003e43.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.9091%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 3.80165%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 9.75207%;\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 8.26446%;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 10.7438%;\"\u003e\n \u003cp\u003e34.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 11.7355%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"10\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003eLegend: b - Chi-square test.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eThe clinical pregnancy rate according to the woman\u0026apos;s age was analyzed, dividing all patients into three groups: under 40 years, 40 to 44 years, and over 45 years. The pregnancy rates per woman by age were 50%, 45.3%, and 37.9%, respectively, with p = 0.094. Data relating to the obstetric outcomes are summarized in Table 4. In the ESDP group there were 97 live births over 23 weeks while the IVO group had 79 live births.\u003c/p\u003e\n\u003cp\u003eTable 4 - Obstetric and Neonatal Outcomes\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003eEgg-sharing donation program\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003eImported vitrified oocytes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 521px;\"\u003e\n \u003cp\u003ePercentile, total/number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.036\u003c/strong\u003e\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003eSGA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003e21/97(21.6) *\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003e6/78(7.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"3\" valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003eAGA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003e73/97(75.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003e68/78(87.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003eLGA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003e3/97(3.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003e4/78(5.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003eGestational age, weeks\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003e36.9\u0026plusmn; 3.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003e37.4\u0026plusmn;1.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e0.168\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003eBirth weight, (Fetus 1), g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003e2842\u0026plusmn;765\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003e3048\u0026plusmn; 547\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.040\u003c/strong\u003e\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 226px;\"\u003e\n \u003cp\u003eBirth weight, (Fetus 2), g\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 167px;\"\u003e\n \u003cp\u003e1866\u0026plusmn;566\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 129px;\"\u003e\n \u003cp\u003e2100**\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 83px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eLegend: Data are presented as mean \u0026plusmn; SD or total/number (%). * Indicates that 8 (38%) were twins. ** Indicates one newborn. SGA = Small for Gestational Age; AGA = Appropriate for Gestational Age; LGA = Large for Gestational Age. a - Student\u0026apos;s t-test; b - Chi-square test.\u003c/p\u003e\n\u003cp\u003eA few clinical data were collected prospectively when importation began.\u0026nbsp;These data are summarized below in Table 5.\u003c/p\u003e\n\u003cp\u003eTable 5 - Clinical Data Presented by IVF Cycles\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003eEgg-sharing donation program\u003c/p\u003e\n \u003cp\u003en= 43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003eImported vitrified oocytes\u003c/p\u003e\n \u003cp\u003en= 179\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003eP\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eDonor age, years\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e30.6\u0026plusmn;2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e24.1\u0026plusmn;3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eBMI recipient, kg/m2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e25.1\u0026plusmn;4.0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e23.4\u0026plusmn; 3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.020\u003c/strong\u003e\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eBMI oocyte donor, kg/m2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e24.4\u0026plusmn; 3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e21.6\u0026plusmn;2.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026lt;0.001\u003c/strong\u003e\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003ePrevious IVF history, total/number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e30/40(75)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e146/177(82.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.271\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eNumber of previous IVF cycles\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e2.03\u0026plusmn;1.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e2.15\u0026plusmn;1.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.675\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 86.6116%;\"\u003e\n \u003cp\u003ePrevious history,total/number (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eMenopause\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e8/39 (20.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e12/163(7.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.031\u003c/strong\u003e\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eSmoking\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e1/40(2.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e6/170(3.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.781\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eEndometriosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e9/40(22.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e36/174(20.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.830\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eAdenomiosis\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e7/40(17.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e39/172(22.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.531\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eHipotiroidism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e8/40(20)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e25/172(14.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.467\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eHigh blood pressure\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e1/40(2.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e12/172(7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.470\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003ePsychiatric disease\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e3/40(7.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e22/172(12.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.427\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003eNulliparous\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e19/40(47.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e86/173(49.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.862\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003ePrevious Miscarriage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e13/40(32.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e60/173(34.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.855\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003ePrevious Ectopic Pregnancy\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e1/40(2.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e10/173(5.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.694\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 39.6694%;\"\u003e\n \u003cp\u003ePrevious live birth\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 26.4463%;\"\u003e\n \u003cp\u003e10/40(25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 20.4959%;\"\u003e\n \u003cp\u003e25/173(14.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 13.3884%;\"\u003e\n \u003cp\u003e0.153\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eLegend: Data are presented as mean \u0026plusmn; SD or total/number (%). \u0026nbsp;BMI = Body Mass Index. Values are presented as mean \u0026plusmn; standard deviation or percentage. 1 - Student\u0026apos;s t-test; 2 - Chi-square test. When n differs from the absolute number, it is indicated in parentheses.\u003c/p\u003e\n\u003cp\u003eData related to obstetric outcomes are summarized in Table 6.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTable 6 - Obstetric and Neonatal Outcomes\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\"\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 45.7851%;\"\u003e\n \u003cp\u003eOutcomes, total/number (%)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.6777%;\"\u003e\n \u003cp\u003eEgg-sharing donation program\u003c/p\u003e\n \u003cp\u003en= 18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.1818%;\"\u003e\n \u003cp\u003eImported vitrified oocytes\u003c/p\u003e\n \u003cp\u003en=79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.3554%;\"\u003e\n \u003cp\u003ep\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 45.7851%;\"\u003e\n \u003cp\u003eGestational hypertension\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.6777%;\"\u003e\n \u003cp\u003e4/18(22.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.1818%;\"\u003e\n \u003cp\u003e12/78(15.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.3554%;\"\u003e\n \u003cp\u003e0.492\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 45.7851%;\"\u003e\n \u003cp\u003ePreeclampsia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.6777%;\"\u003e\n \u003cp\u003e2/18(11.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.1818%;\"\u003e\n \u003cp\u003e10/78(12.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.3554%;\"\u003e\n \u003cp\u003e0.843\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 45.7851%;\"\u003e\n \u003cp\u003eGestational Diabetes Mellitus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.6777%;\"\u003e\n \u003cp\u003e5/18(27.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.1818%;\"\u003e\n \u003cp\u003e10/78(12.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.3554%;\"\u003e\n \u003cp\u003e0.148\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 45.7851%;\"\u003e\n \u003cp\u003eNeonatal ICU\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.6777%;\"\u003e\n \u003cp\u003e2/18(11.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 18.1818%;\"\u003e\n \u003cp\u003e4/78 (5.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 17.3554%;\"\u003e\n \u003cp\u003e0.313\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eLegend:\u0026nbsp;Data are presented as total/number (%). ICU = Intensive Care Unit. b = Chi-square test.\u003c/p\u003e\n\u003cp\u003eWe also analyzed additional data in the prospective cohort since 2021, comparing the ESDP and IVO groups. The following data were reported: mean number of mature oocytes was 8.26 \u0026plusmn; 3.25 vs. 6.88 \u0026plusmn; 1.69, p \u0026lt; 0.001; clinical pregnancy rate was 41.2% (28/68) vs. 47.4% (111/234), p = 0.408; and live birth and ongoing pregnancy rate was 27.9% (19/68) vs. 38% (89/234), p = 0.151.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eThe analysis comparing the two-egg donation (ED) programs, egg-sharing and imported vitrified oocytes, suggested similar results.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAt the reproductive medicine center involved in this study, treatments using imported vitrified oocytes from international oocyte banks were initiated in 2021. Between 2021 and 2023, we imported 1,230 oocytes. Before 2021, the only option for treatments involving ED was egg-sharing. Data from the Report of the National Embryo Production System reveal that 3,754 clinical pregnancies were achieved with the help of ED from 2020 to 2023 in Brazil (923 from fresh oocytes and 2,831 from frozen oocytes) [10]. This reflects the growing demand for ED treatments in our country. This trend is not only evident in Brazil but also in other countries [5]. It is motivated by various socioeconomic factors, such as delays in childbearing and increases in the age of first pregnancy [6]. The high demand for ED leads to a search for new treatment alternatives, considering that egg-sharing relies on the availability of donors, which remains limited [11]. In this context, IVO from international oocyte banks has become an important alternative. Below, we discuss the main findings of this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical and Laboratory Data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the IVO group\u0026nbsp;we noted a significantly higher number of mature, inseminated, and fertilized oocytes. This can be attributed to two factors: first, in the egg-sharing program, we rely on donor response to ovarian stimulation. Second, in the IVO group, recipients can choose how many mature oocytes they wish to import, and the thawing survival rate was 93%. An observational study from Cobo\u003cem\u003e\u0026nbsp;et al.\u003c/em\u003e, 2015,\u0026nbsp;reported a survival rate of 90.4% in a donation program involving vitrified oocytes\u0026nbsp;and another study, from Greco\u003cem\u003e\u0026nbsp;et a\u003c/em\u003el, 2022, reported an 88.2% oocyte survival rate for imported oocytes [12, 13].\u0026nbsp;Our oocyte survival rate was comparable. Laboratory results from our study suggest that vitrified oocytes subjected to international transport yield similar laboratory results as fresh donated oocytes, reinforcing this viable option as a reproductive medicine treatment.\u003c/p\u003e\n\u003cp\u003eWe observed a higher rate of fresh embryo transfers in the IVO group. In our practice,\u0026nbsp;ESDP\u0026nbsp;recipients synchronize their menstrual cycles with their donor to facilitate fresh embryo transfer. The recipient prepares the endometrium while the donor undergoes ovarian stimulation. However, it is not uncommon for the endometrium not to respond adequately, necessitating a freeze-all approach in such cases. In the IVO cycle, thawing oocytes is only authorized after ensuring adequate endometrial preparation, which explains the higher rates of fresh embryo transfers in this group. According to recent meta-analysis data, a freeze-all strategy does not impair pregnancy chances [14];\u0026nbsp;however, it does increase treatment costs for patients.\u003c/p\u003e\n\u003cp\u003eRegarding patients' medical history, the majority had already attempted an average of two IVF cycles prior to seeking egg donation, indicating the emotional process of elaboration and mourning associated with giving up genetic\u0026nbsp;capital [15].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn the context of Pre-Implantation Genetic Testing for Aneuploidy (PGTA) cycles, it is important to highlight the high percentage found in this study. In Brazil, patients can legally choose whether to undergo PGTA, which may reflect their desire to increase clinical pregnancy chances considering past treatment failures and to gain more information about the embryos, given that the donor remains unknown to them. However, it is crucial to consider previous studies indicating that PGTA does not improve clinical outcomes in cycles utilizing donor oocytes compared to those without PGTA [16, 17]. Furthermore, a recent study published in 2024 showed poorer outcomes for PGTA in fresh oocyte donation cycles, including lower live birth rates and cumulative live birth rates [18].\u0026nbsp;Thus, current evidence suggests that performing PGTA on embryos derived from oocyte donors may have limited benefits; its application should be carefully evaluated, considering the additional treatment costs and time required without clear improvements in clinical outcomes, and it may even lead to poorer outcomes in some contexts.\u003c/p\u003e\n\u003cp\u003eAn interesting finding is that the mean number of mature oocytes has changed in recent years: when we analyzed data from 2021 onwards, the ESDP group had a statistically significant higher number of mature oocytes. Since we began importing oocytes and offering another treatment option, the selection criteria for donors have become more stringent, with the egg-sharing program now accepting only patients with excellent ovarian reserves. This more careful selection process has been associated with the increased number of mature oocytes observed in the egg-sharing program after 2021.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEmbryo Transfer Data\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere were more blastocyst transfers in the IVO group.\u0026nbsp;This data highlights the evolution ofbART, with a reduction in cleavage stage transfers.\u0026nbsp;The data for the\u0026nbsp;ESDP\u0026nbsp;were collected from 2010 to 2023, while importation began in 2021.\u0026nbsp;Currently, the transfer and vitrification of blastocysts are widely recommended\u0026nbsp;[19].\u0026nbsp;This shift is associated with higher rates of clinical pregnancy, as demonstrated in a 2015 study that showed significantly higher pregnancy rates when comparing blastocyst transfers with cleavage stage transfers (43.1% vs. 24%, p = 0.041) [20].\u0026nbsp;Moreover, current evidence suggests there is no difference in blastocyst formation rates when comparing embryos created from fresh versus vitrified donated oocytes [21, 22].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAnother interesting aspect is the trend toward single embryo transfer (SET). Brazilian legislation currently permits the transfer of a maximum of two embryos during egg donation [7], whereas this number was higher according to previous regulations. Results indicated that only half of the transfers in the ESDP group were SET, and both the average number of embryos transferred, and the percentage of twin pregnancies were higher in the ESDP group. It is well-known that twin pregnancies are associated with higher rates of obstetric complications, such as hypertension, pre-eclampsia, premature birth, and increased risks of neonatal complications, including lower birth weight and respiratory distress syndrome, as well as psychological, social, and financial challenges for families\u0026nbsp;[23].\u0026nbsp;Therefore, we must always inform patients about the heightened obstetric risks associated with twin pregnancies before proceeding with the transfer of two embryos.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical Pregnancy Rate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical pregnancy, live birth and ongoing pregnancy rates were similar between\u0026nbsp;the two groups. Rates of miscarriage and ectopic pregnancy were also\u0026nbsp;comparable.\u0026nbsp;A study evaluating clinical pregnancy rates between oocyte donation using vitrified oocytes and fresh cycles reported similar findings, with a clinical pregnancy rate of 60.9% in the fresh group and 59.0% in the vitrified group (p = 0.771) [21].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eA factor found to be associated with lower clinical pregnancy rates was the endometrial thickness in the IVO group.\u0026nbsp;There is extensive literature highlighting the importance of endometrium in embryo transfer [24, 25, 26, 27]. In our study, higher clinical pregnancy rates in the IVO group were associated with endometrial thickness measurements between 8-12 mm on transfer day.\u003c/p\u003e\n\u003cp\u003eThe cumulative pregnancy rate per IVF cycle was similar between the groups and within expected ranges. A study on vitrified egg donation reported a clinical pregnancy rate of 48.4% per donation cycle [12].\u0026nbsp;Additionally, Ermanno Greco\u0026nbsp;\u003cem\u003eet al\u003c/em\u003e. reported a clinical pregnancy rate of 51.8% with imported vitrified oocytes\u0026nbsp;[13].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFinally, there was no statistically significant difference in clinical pregnancy rates when the analyses were performed by separating women into age groups. However, the data indicated a tendency towards lower pregnancy rates for women over 45 years old. Jason S. Yeh\u0026nbsp;\u003cem\u003eet al\u003c/em\u003e reported similar findings, showing lower clinical pregnancy rates in recipients older than 45 years (45-49 years old: OR 0.92, 95% CI: 0.86–0.98; p = 0.01; ≥50 years old: OR 0.81, 95% CI: 0.71–0.93; p = 0.002) [28].\u0026nbsp;Similarly, Campos \u003cem\u003eet al.,\u0026nbsp;\u003c/em\u003e2008\u003cem\u003e,\u003c/em\u003e reported that recipients older than 38 years old had lower pregnancy and implantation rates, suggesting that age may be an important factor for uterine receptivity, regardless\u0026nbsp;of the age of the oocytes\u0026nbsp;[29].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObstetric Outcomes\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe incidence of gestational diabetes mellitus (GDM) was\u0026nbsp;higher in the\u0026nbsp;ESDP group,\u0026nbsp;although this difference was not statistically significant. The recipients in the ESDP group had higher body mass indexes (BMIs), which could explain the increased incidence of GDM in this group. The prevalence of GDM in the general population varies from 1.4% to 6.1% [30].\u0026nbsp;In the present study,\u0026nbsp;the incidence was 27.8%\u0026nbsp;in ESDP and 12.8% in the IVO group.\u0026nbsp;A study evaluating the impact of the health of recipients with obstetric comorbidities observed an incidence of 28% of GDM in women over 40 years of age, compared to 4% in women under 39 years, suggesting that age significantly affects these statistics [31].\u003c/p\u003e\n\u003cp\u003eCurrently, several studies associate higher risks of preeclampsia and hypertension with any form of\u0026nbsp;ART [32, 33, 34].\u0026nbsp;Moreover, some research has indicated even higher rates of hypertensive disorders associated with donated oocytes [35, 36, 37]. Consistent with these findings, we observed a high incidence of gestational hypertension and preeclampsia in both groups analyzed. It is essential to inform egg recipients about these increased risks for developing pregnancy-related comorbidities and to ensure they are referred to high-risk pregnancy prenatal care for appropriate follow-up.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eBirth Weight and Percentile\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe IVO group was associated with higher birth weights\u0026nbsp;compared to the ESDP\u0026nbsp;group; however, most newborns in both groups were classified as appropriate for gestational age (AGA).\u0026nbsp;In contrast, the ESDP was associated with higher rates of small for gestational age (SGA) infants. This discrepancy could be attributed to the higher rate of twin pregnancies in the ESDP group, even though only 38% of SGA newborns were twins. Previous studies have demonstrated similar findings, with a meta-analysis from 2016 showing that the risk of SGA was nearly twice as likely in ED pregnancies compared to autologous IVF pregnancies (OR 1.81, 95% CI 1.26–2.60)\u0026nbsp;(OR 1.81, 95% CI 1.26–2.60) [38].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStudy’s limitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe main limitation of this study was its retrospective nature. Additionally, various strategies (such as laboratory protocols, laboratory environment, methods of embryo culture, form of embryo and gamete manipulation) have been employed since 2010, and new technologies have been incorporated over time.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eIn conclusion, both treatments exhibited similar clinical pregnancy rates. This indicates that imported vitrified oocytes yield outcomes comparable to those of the Egg-Sharing Donation Program, which plays an important role in ED treatments. It is crucial to pay attention to endometrial thickness in recipients prior to embryo transfer; specifically, an endometrial thickness of 8-12 mm was associated with higher clinical pregnancy rates among patients using imported oocytes. Furthermore, recipients should be counseled about the increased risks of obstetric comorbidities compared to the general population.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eEgg Donation (ED)\u003c/p\u003e\n\u003cp\u003eAssisted Reproduction Techniques (ART)\u003c/p\u003e\n\u003cp\u003ePrimary Ovarian Insufficiency (POI)\u003c/p\u003e\n\u003cp\u003eIn Vitro Fertilization (IVF)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEgg-Sharing Donation Program (ESDP)\u003c/p\u003e\n\u003cp\u003eImported Vitrified Oocytes (IVO)\u003c/p\u003e\n\u003cp\u003eIntracytoplasmic Sperm Injection (ICSI)\u003c/p\u003e\n\u003cp\u003ePre-Implantation Genetic Testing for Aneuploidy (PGTA)\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Research Ethics Committee of Pontifical Catholic University of Rio Grande do Sul, protocol number 5.038.470, waving consent term for participants due to this study’s retrospective design. Nevertheless, an informed consent term was signed from all patients allowing data for further research, as outlined in the regular center’s IVF protocol. Furthermore, all authors signed a confidentiality responsibility term\u0026nbsp;prior to the retrospective data collection. The methodology employed adhered to the guidelines and regulations set forth by Declaration of Helsinki.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable, since this study does not contain data from any individual person.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo preserve confidential patient’s information, data are not openly available; However, it could be obtained upon reasonable requests in the ScienceDB repository on which all datasets generated and/or analyzed during the current study are available at following links:\u003c/p\u003e\n\u003cp\u003ehttps://download.scidb.cn/download?fileId=a888646afc8e528883df1739684d7b47\u0026amp;path=/V1/retrospective.xlsx\u0026amp;[email protected]\u0026amp;fileName=retrospective%20.xlsx\u003c/p\u003e\n\u003cp\u003ehttps://download.scidb.cn/download?fileId=22ec81306c0480ef3b53e01286e1cbc1\u0026amp;path=/V1/prospective.xlsx\u0026amp;[email protected]\u0026amp;fileName=prospective.xlsx.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll the authors declare no competing interests.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors’ contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eVDT and MRH performed the study design, collection of data, data analysis, manuscript drafting and critical discussion.VCD, IBT and NFV were involved incollection of data and manuscript drafting.TC participated in the study’s design definition, critical discussion of results and manuscript drafting. AP, CEPF and MB performedcritical discussion and final manuscript approval.All authors read and approved the final manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors would like to express their heartfelt gratitude to all the participating patients and the dedicated team involved in our oocyte donation program.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMelnick AP, Rosenwaks Z. Oocyte donation: insights gleaned and future challenges. Fertil Steril. 2018;110(6):988-93.\u003c/li\u003e\n\u003cli\u003eLutjen P, Trounson A, Leeton J, Findlay J, Wood C, Renou P. The establishment and maintenance of pregnancy using in vitro fertilization and embryo donation in a patient with primary ovarian failure. Nature. 1984;307(5947):174-5.\u003c/li\u003e\n\u003cli\u003eGuidance regarding gamete and embryo donation. (2021) Fertil Steril. \u003c/li\u003e\n\u003cli\u003eBracewell-Milnes T, Hossain A, Jones BP, Faris R, Parikh J, Nicopoullos J, Johnson M, Thum MY. Does egg-sharing negatively impact on the chance of the donor or recipient achieving a live birth? Hum Fertil (Camb). 2023;26(2):266-75.\u003c/li\u003e\n\u003cli\u003eColombo T, Hentschke MR, Badalotti M, Kira ATF, Tel\u0026ouml;ken IB, Trindade VD, Dornelles VC, Petracco A, Wendland EM. A sharing oocyte donation program: a 15-year cohort study. JBRA Assist Reprod. 2023;27(3):348-54.\u003c/li\u003e\n\u003cli\u003eBraga DP, Setti AS, Figueira RC, Azevedo Mde C, Iaconelli A Jr, Lo Turco EG, Borges EJ Jr. Freeze-all, oocyte vitrification, or fresh embryo transfer? Lessons from an egg-sharing donation program. Fertil Steril. 2016;106(3):615-22.\u003c/li\u003e\n\u003cli\u003eConselho Federal de Medicina. Resolu\u0026ccedil;\u0026atilde;o CFM n\u0026ordm; 2.294, de 27 de maio de 2021. Di\u0026aacute;rio Oficial da Uni\u0026atilde;o; 2021.\u003c/li\u003e\n\u003cli\u003eThe Vienna consensus: report of an expert meeting on the development of ART laboratory performance indicators. Reprod BioMed Online. 2017;35(5):494\u0026ndash;510.\u003c/li\u003e\n\u003cli\u003ePSS Health: Power and Sample Size for Health Researchers. Available at: https://hcpa-unidade-bioestatistica.shinyapps.io/PSS_Health. Accessed Jun 2024.\u003c/li\u003e\n\u003cli\u003eANVISA. SisEmbrio - Relat\u0026oacute;rio do Sistema Nacional de Produ\u0026ccedil;\u0026atilde;o de Embri\u0026otilde;es. Available at: https://www.gov.br/anvisa/pt-br/acessoainformacao/dadosabertos/informacoes-analiticas/sisembrio. Accessed 2024.\u003c/li\u003e\n\u003cli\u003eBraga D, Setti AS, Iaconelli A Jr, Borges E Jr. Predictive factors for successful pregnancy in an egg-sharing donation program. JBRA Assist Reprod. 2020;24(2):163-9.\u003c/li\u003e\n\u003cli\u003eCobo A, Garrido N, Pellicer A, Remoh\u0026iacute; J. Six years\u0026apos; experience in ovum donation using vitrified oocytes: report of cumulative outcomes, impact of storage time, and development of a predictive model for oocyte survival rate. Fertil Steril. 2015;104(6):1426-34.e1-8.\u003c/li\u003e\n\u003cli\u003eGreco E, Donno V, Greco A, Minasi MG, Prister\u0026agrave; A, Pirastu G, et al. Which factors influence the success rate of egg donation programmes with imported vitrified oocytes? Reprod Biomed Online. 2022;45(2):264-73.\u003c/li\u003e\n\u003cli\u003eZaat T, Zagers M, Mol F, Goddijn M, van Wely M, Mastenbroek S. Fresh versus frozen embryo transfers in assisted reproduction. Cochrane Database Syst Rev. 2021;2(2)\u003c/li\u003e\n\u003cli\u003eLasheras G, Mestre-Bach G, Clua E, Rodr\u0026iacute;guez I, Farr\u0026eacute;-Sender B. Cross-Border Reproductive Care: Psychological Distress in A Sample of Women Undergoing In Vitro Fertilization Treatment with and without Oocyte Donation. Int J Fertil Steril. 2020;14(2):129-35.\u003c/li\u003e\n\u003cli\u003eMasbou AK, Friedenthal JB, McCulloh DH, McCaffrey C, Fino ME, Grifo JA, Licciardi F. A Comparison of Pregnancy Outcomes in Patients Undergoing Donor Egg Single Embryo Transfers With and Without Preimplantation Genetic Testing. Reprod Sci. 2019;26(12):1661-5.\u003c/li\u003e\n\u003cli\u003eDoyle N, Gainty M, Eubanks A, Doyle J, Hayes H, Tucker M, et al. Donor oocyte recipients do not benefit from preimplantation genetic testing for aneuploidy to improve pregnancy outcomes. Hum Reprod. 2020;35(11):2548-55.\u003c/li\u003e\n\u003cli\u003eGingold JA, Kucherov A, Wu H, Fazzari M, Lieman H, Ball GD, et al. PGT-A is Associated with Reduced Live Birth Rates in Fresh but not Frozen Donor Oocyte IVF cycles: An Analysis of 18,562 Donor Cycles Reported to SART CORS. Fertil Steril. 2024.\u003c/li\u003e\n\u003cli\u003eGlujovsky D, Quinteiro Retamar AM, Alvarez Sedo CR, Ciapponi A, Cornelisse S, Blake D. Cleavage-stage versus blastocyst-stage embryo transfer in assisted reproductive technology. Cochrane Database Syst Rev. 2022;5(5)\u003c/li\u003e\n\u003cli\u003eFern\u0026aacute;ndez-Shaw S, Cercas R, Bra\u0026ntilde;a C, Villas C, Pons I. Ongoing and cumulative pregnancy rate after cleavage-stage versus blastocyst-stage embryo transfer using vitrification for cryopreservation: impact of age on the results. J Assist Reprod Genet. 2015;32(2):177-84.\u003c/li\u003e\n\u003cli\u003eDomingues TS, Aquino AP, Barros B, Mazetto R, Nicolielo M, Kimati CM, et al. Egg donation of vitrified oocytes bank produces similar pregnancy rates by blastocyst transfer when compared to fresh cycle. J Assist Reprod Genet. 2017;34(11):1553-7.\u003c/li\u003e\n\u003cli\u003eGarc\u0026iacute;a JI, Noriega-Portella L, Noriega-Hoces L. Efficacy of oocyte vitrification combined with blastocyst stage transfer in an egg donation program. Hum Reprod. 2011;26(4):782-90.\u003c/li\u003e\n\u003cli\u003eGerris JM. Single embryo transfer and IVF/ICSI outcome: a balanced appraisal. Hum Reprod Update. 2005;11(2):105-21.\u003c/li\u003e\n\u003cli\u003eDain L, Bider D, Levron J, Zinchenko V, Westler S, Dirnfeld M. Thin endometrium in donor oocyte recipients: enigma or obstacle for implantation? Fertil Steril. 2013;100(5):1289-95.\u003c/li\u003e\n\u003cli\u003eVartanyan E, Tsaturova K, Devyatova E. Thin endometrium problem in IVF programs. Gynecol Endocrinol. 2020;36(sup1):24-7.\u003c/li\u003e\n\u003cli\u003eLiu KE, Hartman M, Hartman A, Luo ZC, Mahutte N. The impact of a thin endometrial lining on fresh and frozen-thaw IVF outcomes: an analysis of over 40 000 embryo transfers. Hum Reprod. 2018;33(10):1883-8.\u003c/li\u003e\n\u003cli\u003eGallos ID, Khairy M, Chu J, Rajkhowa M, Tobias A, Campbell A, et al. Optimal endometrial thickness to maximize live births and minimize pregnancy losses: Analysis of 25,767 fresh embryo transfers. Reprod Biomed Online. 2018;37(5):542-8.\u003c/li\u003e\n\u003cli\u003eYeh JS, Steward RG, Dude AM, Shah AA, Goldfarb JM, Muasher SJ. Pregnancy outcomes decline in recipients over age 44: an analysis of 27,959 fresh donor oocyte in vitro fertilization cycles from the Society for Assisted Reproductive Technology. Fertil Steril. 2014;101(5):1331-6.\u003c/li\u003e\n\u003cli\u003eCampos I, G\u0026oacute;mez E, Fern\u0026aacute;ndez-Valencia AL, Landeras J, Gonz\u0026aacute;lez R, Coy P, et al. Effects of men and recipients\u0026apos; age on the reproductive outcome of an oocyte donation program. J Assist Reprod Genet. 2008;25(9-10):445-52.\u003c/li\u003e\n\u003cli\u003eBrody SC, Harris R, Lohr K. Screening for gestational diabetes: a summary of the evidence for the U.S. Preventive Services Task Force. Obstet Gynecol. 2003;101:380-92. doi:10.1016/s0029-7844(02)03057-0.\u003c/li\u003e\n\u003cli\u003eMichalas S, Loutradis D, Drakakis P, Milingos S, Papageorgiou J, Kallianidis K, et al. Oocyte donation to women over 40 years of age: pregnancy complications. Eur J Obstet Gynecol Reprod Biol. 1996;64(2):175-8. doi:10.1016/0028-2243(96)02693-3.\u003c/li\u003e\n\u003cli\u003eYadav V, Bakolia P, Malhotra N, Mahey R, Singh N, Kriplani A. Comparison of obstetric outcomes of pregnancies after donor-oocyte in vitro fertilization and self-oocyte in vitro fertilization: A retrospective cohort study. J Hum Reprod Sci. 2018;11(4):370-5.\u003c/li\u003e\n\u003cli\u003eAlmasi-Hashiani A, Omani-Samani R, Mohammadi M, Amini P, Navid B, Alizadeh A, et al. Assisted reproductive technology and the risk of preeclampsia: an updated systematic review and meta-analysis. BMC Pregnancy Childbirth. 2019;19(1):149.\u003c/li\u003e\n\u003cli\u003eKornfield MS, Gurley SB, Vrooman LA. Increased risk of preeclampsia with assisted reproductive technologies. Curr Hypertens Rep. 2023;25(9):251-61.\u003c/li\u003e\n\u003cli\u003eRodriguez-Wallberg KA, Berger AS, Fagerberg A, Olofsson JI, Scherman-Pukk C, Lindqvist PG, et al. Increased incidence of obstetric and perinatal complications in pregnancies achieved using donor oocytes and single embryo transfer in young and healthy women. A prospective hospital-based matched cohort study. Gynecol Endocrinol. 2019;35(4):314-9.\u003c/li\u003e\n\u003cli\u003eLevron Y, Dviri M, Segol I, Yerushalmi GM, Hourvitz A, Orvieto R, et al. The \u0026apos;immunologic theory\u0026apos; of preeclampsia revisited: a lesson from donor oocyte gestations. Am J Obstet Gynecol. 2014;211(4):383.e1-5.\u003c/li\u003e\n\u003cli\u003eBl\u0026aacute;zquez A, Garc\u0026iacute;a D, Rodr\u0026iacute;guez A, Vassena R, Figueras F, Vernaeve V. Is oocyte donation a risk factor for preeclampsia? A systematic review and meta-analysis. J Assist Reprod Genet. 2016;33(7):855-63.\u003c/li\u003e\n\u003cli\u003eJeve YB, Potdar N, Opoku A, Khare M. Donor oocyte conception and pregnancy complications: a systematic review and meta-analysis. Bjog. 2016;123(9):1471-80.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Oocyte Donation, assisted reproduction techniques, infertility, gamete donation.","lastPublishedDoi":"10.21203/rs.3.rs-5282943/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5282943/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: In the past decade, the use of donated oocytes has increased, with egg donation (ED) cycles accounting for nearly 10% of all assisted reproductive technology (ART) in the United States, with live birth rates exceeding 50% per cycle. Legal frameworks for ED vary across countries; for example, Brazil permits voluntary and shared donation but prohibits commercial donation, leading to imported egg-sharing programs. Despite the growing use of both fresh and vitrified oocytes, no studies have yet compared pregnancy rates between these different egg-sharing programs. Does the use of imported vitrified oocytes from an international bank result in similar pregnancy rates when compared to an egg-sharing donation with fresh oocytes?\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods\u003c/strong\u003e: This study is a retrospective cohort including in vitro fertilization (IVF) cycles involving egg donation from January 2010 to December 2023. Patients were divided into two groups: those participating in the egg-sharing program and those receiving imported vitrified oocytes from an international bank.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e: A total of 391 patients were included, with 224 from egg-sharing group (comprising 251 IVF cycles) and 170 from the imported vitrified oocyte group (comprising 179 IVF cycles). The data between the groups were as follows, respectively: mature oocytes: 6.11±3.03, vs 6.88 ±1.69, p = 0.001; total embryos formed: 3.10±1.78, vs 3.26±1.73, p = 0.373, clinical pregnancy rate: 40.1%, vs 47.4%, p = 0.099, live birth and ongoing pregnancy rate: 30.7% vs 38%, p = 0.084, birth weight 2842±765 vs 3048± 547, p = 0.040, small for gestational age 21.6 vs 7.7%, p = 0.036. In the imported oocytes group, the pregnancy rates according to endometrial thickness were as follows: \u0026lt;8mm: 23.5%, 8-12mm: 53.8%,\u0026gt;12 mm 34.6%, p = 0.002.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusions\u003c/strong\u003e: Egg recipient treatment using imported vitrified oocytes demonstrated similar laboratory outcomes and clinical pregnancy rates compared to the egg-sharing program. Additionally, recipients using vitrified oocytes achieved higher pregnancy rates when transfers were conducted with an endometrial thickness of 8-12 mm.\u003c/p\u003e","manuscriptTitle":"Pregnancy outcomes in egg donation programs are similar when vitrified imported oocytes are compared to egg-sharing in a retrospective cohort study. 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