Fresh Embryo Transfer Group Research Articles

The effects of fresh embryo transfer and frozen-thawed embryo transfer on the perinatal outcomes of single fetuses from mothers with PCOS.

To investigate the effects of fresh embryo transfer and frozen-thawed embryo transfer on perinatal outcomes among patients with PCOS. Patients who underwent in vitro fertilization and embryo transfer at the reproductive medicine center of the Affiliated Hospital of Guangdong Medical University from February 2013 to March 2021 were retrospectively analyzed. Patients were divided into the fresh embryo transfer group and frozen-thawed embryo transfer group according to whether fresh embryo transfer was performed. According to their conditions, patients were further classified into the ET-PCOS group (group A, n = 104), ET-non-PCOS group (group B, n = 212), FET-PCOS group (group C, n = 102), or FET-non-PCOS group (group D, n = 148); the general data, laboratory indicators and pregnancy outcomes of the patients were statistically analyzed, and the perinatal outcomes and related factors between the groups were compared and analyzed. The level of E2 on the HCG test day in the ET group was lower than that in the FET group. The natural birth rate of group D was lower than that of group A and group B, and the cesarean section rate was higher than that of group A and group B; the clinical pregnancy rate of group A was higher than that of group B and group D, and the difference was statistically significant (P < 0.05). There was no significant difference in the total abortion rate, early abortion rate or late abortion rate between the groups (P > 0.05). There was no significant difference in gestational age, neonatal sex or neonatal weight between the groups (P > 0.05). The incidence of placenta previa in Group B was significantly lower than that in Group D, and the difference was significant (P < 0.05). The incidence of fetal distress in Group B was significantly lower than that in Groups C and D, and the incidence of neonatal jaundice in Group D was significantly higher than that in Groups A and B (P < 0.05). In the multivariate analysis, the number of high-quality embryos was independent factors affecting clinical pregnancy, and the embryo transfer method was an independent factor affecting fetal distress and neonatal jaundice. Young PCOS patients without risk of OHSS have a high clinical pregnancy rate with fresh transplant cycles. PCOS disease itself has no significant effect on the perinatal outcomes of the mother or singleton infant. Frozen-thawed embryo transfer may increase the incidence of low placenta, fetal distress and neonatal jaundice.

Sexual intercourse before embryo transfer in assisted reproductive technology might enhance probability of pregnancy: An observational study.

Modifying the maternal immune system is necessary to facilitate embryo implantation. Modifying the immune system can occur in several ways, including maternal exposure to the partner's seminal plasma. Seminal plasma exposure can occur through sexual intercourse. To prove this theory, we investigate the effect of sexual intercourse on the chances of successful in vitro fertilization (IVF) in both fresh and frozen embryo transfer (ET) groups in terms of biochemical and clinical pregnancy. This is an observational analytical study with a retrospective cohort study design. This study compared biochemical and clinical pregnancy in patient groups who had sexual intercourse with those who did not have sexual intercourse during the IVF process. This study involved 132 participants. The results of this study reported that there was no significant difference in pregnancy rates between patients who had sex before ET and those who did not have sex before ET. However, patients who experience orgasm during sex show significant rates of biochemical (p = 0.009) and clinical pregnancy (p = 0.027) rates. Sexual intercourse did not show a significant difference between the groups who had sex before ET and those who did not have sex, but the experience of orgasm every time they had sex recently had a positive impact on reproductive health, especially pregnancy.

Reproductive outcomes in women with advanced endometriosis in fresh versus frozen embryo transfer cycles

BackgroundART in women with endometriosis is associated with poor quality of the retrieved oocytes and lower fertilization and pregnancy rates, reflecting that endometriosis may influence fertility by altering the quality of both the oocyte and embryo quality and also by impairing the endometrial receptivity. On comparing endometriosis-affected patients to healthy counterparts, many differences were demonstrated at the endometrial level. Thus, choosing the appropriate method of embryo transfer is of utmost importance, particularly for patients with advanced endometriosis.ObjectiveThe aim of the present study was to compare the reproductive outcomes between fresh and frozen embryo transfer cycles in women with advanced endometriosis.Material and methodsA retrospective cohort study was conducted in the period from January 2018 until December 2021 for patients recruited from two IVF centers, Alexandria, Egypt. Careful review of paper and electronic medical records of infertile women (primary, relative, or secondary infertility) aged 18–37 years who were diagnosed with advanced endometriosis by means of laparoscopy and were scheduled for ICSI followed by either fresh embryo transfer (group I) or freeze-all embryos and deferred embryo transfer (group II) of day 5 embryo(s) was included in the study.ResultsTwo-hundred and eleven women were eligible and included in the study. Women in each study group were matched regarding baseline characteristics. Clinical pregnancy, implantation, and ongoing pregnancy rates were statistically significantly higher in the group of frozen embryo transfer (p < 0.001). Miscarriage rate was found to be higher in the group of fresh transfer compared to FET group but without a statistical significance (20.9% vs 9.2%, p = 0.072).ConclusionIn women with advanced endometriosis, freeze-all policy seems to be associated with better implantation, ongoing pregnancy rates.

ART conceptions: timing of delivery and the risk of hypertensive disorders of pregnancy

Research questionAre there differences in the rates of hypertensive disorders of pregnancy among in vitro fertilization (IVF) patients who underwent induction of labor at 39 weeks compared to those who were managed expectantly? DesignThis is a retrospective cohort study of 1,176 low-risk singleton pregnancies conceived following IVF with no contraindications to vaginal delivery. Two groups were constructed: elective induction of labor from 39 weeks 0 days to 39 weeks 6 days (n=234) versus expectant management (n=942). Main outcome measure was the incidence of hypertensive disorders of pregnancy. Secondary outcome was the rate of cesarean delivery. Sub-analyses were performed within fresh and frozen embryo transfer groups. ResultsHypertensive disorders of pregnancy developed in 8.1% of patients in the induction of labor group and in 12.4% in the expectant management group (P=.06). This difference was attenuated after controlling for potential confounders (P=.28). For frozen embryo transfers, the unadjusted odds of hypertensive disorders of pregnancy were significantly lower with induction of labor compared to expectant management (P=.02) and after adjusting for confounders, the odds ratio neared significance (P=.09). For fresh transfers, there was no difference in the odds of hypertensive disorders of pregnancy between the two groups. The odds of delivering via cesarean section were higher in the induction of labor group, in the total population and in sub-analyses. ConclusionOverall, in IVF conceived pregnancies, induction of labor when compared to expectant management was not associated with a lower incidence of hypertensive disorders of pregnancy, it was however, associated with a higher rate of cesarean delivery.

Safety of embryo cryopreservation: insights from mid-term placental transcriptional changes

BackgroundIn recent years, with benefits from the continuous improvement of clinical technology and the advantage of fertility preservation, the application of embryo cryopreservation has been growing rapidly worldwide. However, amidst this growth, concerns about its safety persist. Numerous studies have highlighted the elevated risk of perinatal complications linked to frozen embryo transfer (FET), such as large for gestational age (LGA) and hypertensive disorders during pregnancy. Thus, it is imperative to explore the potential risk of embryo cryopreservation and its related mechanisms.MethodsGiven the strict ethical constraints on clinical samples, we employed mouse models in this study. Three experimental groups were established: the naturally conceived (NC) group, the fresh embryo transfer (Fresh-ET) group, and the FET group. Blastocyst formation rates and implantation rates were calculated post-embryo cryopreservation. The impact of FET on fetal growth was evaluated upon fetal and placental weight. Placental RNA-seq was conducted, encompassing comprehensive analyses of various comparisons (Fresh-ET vs. NC, FET vs. NC, and FET vs. Fresh-ET).ResultsReduced rates of blastocyst formation and implantation were observed post-embryo cryopreservation. Fresh-ET resulted in a significant decrease in fetal weight compared to NC group, whereas FET reversed this decline. RNA-seq analysis indicated that the majority of the expression changes in FET were inherited from Fresh-ET, and alterations solely attributed to embryo cryopreservation were moderate. Unexpectedly, certain genes that showed alterations in Fresh-ET tended to be restored in FET. Further analysis suggested that this regression may underlie the improvement of fetal growth restriction in FET. The expression of imprinted genes was disrupted in both FET and Fresh-ET groups.ConclusionBased on our experimental data on mouse models, the impact of embryo cryopreservation is less pronounced than other in vitro manipulations in Fresh-ET. However, the impairment of the embryonic developmental potential and the gene alterations in placenta still suggested it to be a risky operation.

P-770 Health outcomes of taiwanese infants after different embryo stages in both fresh and frozen transfer procedures

Abstract Study question Does freezing embryos have any effects on neonatal and postnatal health? Does extended embryo culture have any impact on these health outcomes? Summary answer frozen embryo transfer (FET) infants were more likely be large gestational age, but with lower odds of recurrent upper respiratory infection and dermatitis. What is known already Infants born from frozen embryo transfers tend to have higher birth weights and are less likely to be small for gestational age. There are no notable variations in congenital malformations or child development. However, there’s a lack of long-term follow-up data. Study design, size, duration In this retrospective cohort study conducted in Taiwan, data from the national assisted reproductive technology (ART) database spanning from January 1st, 2013, to December 31st, 2017, was utilized. The study categorizes cases into fresh and frozen embryo transfer groups, with additional subdivisions based on cleavage and blastocyst stage transfers. Singletons born in each group were then linked to the National Health Insurance Database for follow-up on health conditions until December 13th, 2018. Participants/materials, setting, methods We collected data on singleton births resulting from assisted reproductive technology procedures performed in Taiwan from January 1st, 2013, to December 31st, 2017. Our analysis included 10,669 eligible infants. We investigated factors such as gestational age, birth weight, and various systemic diseases, encompassing neurological disorders, facial and eye abnormalities, cardiovascular diseases, respiratory disease, gastrointestinal disorders, renal system disorders, musculoskeletal disorders, skin and submucous disorders, chromosomal abnormalities, infections, and birth injuries. Main results and the role of chance Compared to infants conceived from fresh embryos, those born to mothers who underwent frozen embryo transfer (FET) were more likely to be large for gestational age (OR 1.63, 95% CI 1.30-2.04 for blastocyst and OR 1.69, 95% CI 1.36-2.10 for cleavage stage), and to have a neonatal birth weight of ≥ 4000g (OR 1.88, 95% CI 1.15-3.07 for blastocyst and OR 2.64, 95% CI 1.63-4.28 for cleavage stage). However, they were less likely to be small for gestational age (OR 0.68, 95% CI 0.56-0.82 for blastocyst and OR 0.68, 95% CI 0.56-0.82 for cleavage stage). Infants born from frozen embryo transfers also experienced lower odds of recurrent upper respiratory infection (OR 0.72, 95% CI 0.60-0.86 for blastocyst and OR 0.60, 95% CI 0.52-0.69 for cleavage stage), as well as eczema and dermatitis (OR 0.75, 95% CI 0.62-0.91 for blastocyst and OR 0.75, 95% CI 0.62-0.91 for cleavage stage). There was no observed effect on infant health between blastocyst and cleavage stage embryo transfers. Limitations, reasons for caution Our retrospective study design may not possess the same level of rigor as a randomized controlled trial (RCT). The follow-up period in our study ranged from 1 to 5 years, and some diseases may not manifest within this short-term timeframe, necessitating longer-term tracking for more comprehensive observation. Wider implications of the findings The result highlights the potential benefits of FET in reducing the risk of low birth weight. The observed decrease respiratory infections and skin disorders among FET infants suggests a possible advantage in immune system development or environmental adaptability. Further research with longer-term tracking is warranted. Trial registration number KMUHIRB-E(I)-20210222

Clinical outcomes of fresh and frozen embryos transfer after in vitro fertilization in spouses of patients with severely low sperm concentration and motility.

To compare the pregnancy and neonatal outcomes of in vitro fertilization-embryo transfer (IVF-ET) with fresh or frozen embryos in spouses of patients with severely low sperm concentration and motility. A total of 2300 patients whose spouses have severely low sperm concentration and motility underwent IVT-ET in the Reproduction Medicine Center, Sir Run Run Shaw Hospital from April 2018 to April 2022. After applying the propensity score matching (PSM), 473 fresh embryo transferred cycles and 473 frozen embryo transferred cycles were selected for the study, and the pregnancy and neonatal outcomes were compared between the two groups. There were no significant differences in pregnancy outcomes and neonatal outcomes between fresh and frozen embryo groups (all P>0.05). In the stratification analysis, the number of retrieved oocytes in the fresh good-quality embryo transfer group was significantly increased compared with the fresh poor-quality embryo group (P<0.05), but the very early pregnancy loss rates were similar between the two groups (P>0.05), while the rate in fresh good-quality embryo transfer group was significantly higher than that in the frozen good-quality embryo transfer group (P<0.05). Among different age groups of women, the number of retrieved oocytes and the level of estrogen in the fresh embryo transfer group was significantly higher in the 20 to <30 years old group than that in the 30 to <35 years old group (both P<0.05), but the clinical pregnancy rate was lower in the 20 to <30 years old group than that in the 30 to <35 years old group (P>0.05). Additionally, the very early pregnancy loss was significantly increased in the fresh embryo group compared with the frozen embryo group in the 20 to <30 years age group (P<0.05). There were no significant differences in pregnancy and neonatal outcomes between fresh and frozen embryo transfer in spouses of patients with severely low sperm concentration and motility undergoing IVF-ET. Due to the shorter transfer times, less embryo freezing damage and reduced costs, fresh embryo transfer can be considered as the first choice. However, it is not necessary to pursue fresh embryo transfer if maternal oestrogen levels are too high and there is a tendency of overstimulation.

Diameter of Human Day Five Blastocysts and Birth Sex.

Background This study aimed to evaluate the offspring sex ratio, born through fresh and cryo-thawed single blastocyst (BL) transfers regarding a single morphological, static parameter, namely, BL diameter. Methodology This retrospective, observational study was conducted at an assisted reproductive technology (ART) center, Kinderwunschzentrum Niederrhein Germany. We conducted a statistical analysis of all births resulting from fresh and thawed in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles after a single embryo transfer (SET). The main outcome measure was the offspring sex ratio after SET of a day five BL in relation to the BL diameter measurement. Results There were more female than male babies born in our study. We observed a tendency for BL to have a higher diameter, resulting in female offspring, which was not statistically relevant. We also compared the BL diameter in the fresh embryo transfer (ET) group with that of the cryo-thawed ET group, showing a tendency toward a larger diameter in the fresh ET group. In the ICSI cycles, there was a higher tendency for a larger BL diameter when compared to IVF cycles. In the fresh ET cycles, BL leading to the male sex at birth had a tendency toward a larger diameter than the female BL. In the cryo-thaw ET cycles, BL leading to the female sex had a tendency toward a larger diameter than the male BL. Conclusions Our results showed a tendency in the sex of offspring toward the female sex and no significant difference in the BL diameter of BL leading to birth after ART and consecutive transfer of day five BL.

The difference in early trimester fetal growth between singletons after frozen embryo transfer and fresh embryo transfer

Frozen embryo transfer resulted in a higher birthweight and an increased risk of macrosomia than fresh embryo transfer. However, the mechanism was still unclear. When the impact of frozen embryo transfer on fetal growth began was unknown. Crown-rump length at 11-13 weeks had been regarded as a good indicator of fetal growth in the first trimester and had been used for gestational age calculation in women with uncertain last menstrual periods. To evaluate the association between frozen embryo transfer and early fetal growth, particularly the crown-rump length, then fresh embryo transfer. The secondary objective was to investigate the potential correlation between crown-rump length and birthweight. This was a retrospective cohort study conducted at the Reproductive Medical Center of Shandong University. A total of 4949 patients who obtained singleton pregnancy after frozen embryo transfer and 1793 patients who got singleton pregnancy after fresh embryo transfer between January 1, 2017 and December 31, 2022 were included. The primary outcome was the crown-rump length measured via ultrasound at 11-13 weeks gestation. The secondary outcomes were perinatal outcomes, including birthweight and the risk of large for gestational age, small for gestational age, macrosomia, low birthweight, and premature delivery. Multivariable linear regression models were used to adjust for potential confounders of crown-rump length. A total of 6742 live singleton births after frozen embryo transfer or fresh embryo transfer were included in this study. In the univariable analysis, the frozen embryo transfer group had a larger crown-rump length (5.75±0.53 cm vs 5.57±0.48 cm, P<.001) and an increased risk of larger-than-expected crown-rump length (13.5% vs11.2%, P=.013) than the fresh embryo transfer group. After adjusting for confounders in multivariable linear regression models, frozen embryo transfer was still associated with a larger crown-rump length (regression coefficient, 3.809 [95% confidence intervals, 3.621-3.997], P<.001). When subgrouped by fetal gender, the crown-rump length of the frozen embryo transfer group was larger than the fresh embryo transfer group in both male and female fetuses. In addition, the crown-rump length was consistently larger in the frozen embryo transfer group than the fresh embryo transfer group in subgroups of the peak estradiol levels. The comparisons among different crown-rump length groups showed that smaller-than-expected crown-rump length was associated with increased risks of small for gestational age (6.3% vs 3.0%, P<.001) and preterm delivery (9.6% vs 6.7%, P=.004) than normal crown-rump length. Frozen embryo transfer was associated with a larger crown-rump length than fresh embryo transfer, suggesting that the effect of frozen embryo transfer on fetal growth may begin in the early trimester. Suboptimal fetal growth in the first trimester may be associated with low birthweight and premature delivery.

Is large for gestational age in singletons born after frozen embryo transfer associated with freezing technique or endometrial preparation protocol? A longitudinal national French study.

Is large for gestational age (LGA) observed in babies born after frozen embryo transfer (FET) associated with either the freezing technique or the endometrial preparation protocol? Artificial cycles are associated with a higher risk of LGA, with no difference in rate between the two freezing techniques (vitrification versus slow freezing) or embryo stage (cleaved embryo versus blastocyst). Several studies have compared neonatal outcomes after fresh embryo transfer (ET) and FET and shown that FET is associated with improved neonatal outcomes, including reduced risks of preterm birth, low birthweight, and small for gestational age (SGA), when compared with fresh ET. However, these studies also revealed an increased risk of LGA after FET. The underlying pathophysiology of this increased risk remains unclear; parental infertility, laboratory procedures (including embryo culture conditions and freezing-thawing processes), and endometrial preparation treatments might be involved. A multicentre epidemiological data study was performed through a retrospective analysis of the standardized individual clinical records of the French national register of IVF from 2014 to 2018, including single deliveries resulting from fresh ET or FET that were prospectively collected in fertility centres. Complementary data were collected from the participating fertility centres and included the vitrification media and devices, and the endometrial preparation protocols. Data were collected from 35 French ART centres, leading to the inclusion of a total of 72789 fresh ET, 10602 slow-freezing FET, and 39062 vitrification FET. Main clinical outcomes were presented according to origin of the transferred embryos (fresh, slow frozen, or vitrified embryos) and endometrial preparations for FET (ovulatory or artificial cycles), comparing five different groups (fresh, slow freezing-ovulatory cycle, slow freezing-artificial cycle, vitrification-ovulatory cycle, and vitrification-artificial cycle). Foetal growth disorders were defined in live-born singletons according to gestational age and sex-specific weight percentile distribution: SGA and LGA if <10th and ≥90th percentiles, respectively. Analyses were performed using linear mixed models with the ART centres as random effect. Transfers led to, respectively, 19006, 1798, and 9195 deliveries corresponding to delivery rates per transfer of 26.1%, 17.0%, and 23.5% after fresh ET, slow-freezing FET, and vitrification FET, respectively. FET cycles were performed in either ovulatory cycles (n = 21704) or artificial cycles (n = 34237), leading to 5910 and 10322 pregnancies, respectively, and corresponding to pregnancy rates per transfer of 31.6% and 33.3%. A significantly higher rate of spontaneous miscarriage was observed in artificial cycles when compared with ovulatory cycles (33.3% versus 21.4%, P < 0.001, in slow freezing groups and 31.6% versus 21.8%, P < 0.001 in vitrification groups). Consequently, a lower delivery rate per transfer was observed in artificial cycles compared with ovulatory cycles both in slow freezing and vitrification groups (15.5% versus 18.9%, P < 0.001 and 22.8% versus 24.9%, P < 0.001, respectively). Among a total of 26585 live-born singletons, 16413 babies were born from fresh ET, 1644 from slow-freezing FET, and 8528 from vitrification FET. Birthweight was significantly higher in the FET groups than in the fresh ET group, with no difference between the two freezing techniques. Likewise, LGA rates were higher and SGA rates were lower in the FET groups compared with the fresh ET group whatever the method used for embryo freezing. In a multivariable analysis, the risk of LGA following FET was significantly increased in artificial compared with ovulatory cycles. In contrast, the risk of LGA was not associated with either the freezing procedure (vitrification versus slow freezing) or the embryo stage (cleaved embryo versus blastocyst) at freezing. Regarding the vitrification method, the risk of LGA was not associated with either the vitrification medium used or the embryo stage. No data were available on maternal context, such as parity, BMI, infertility cause, or maternal comorbidities, in the French national database. In particular, we cannot exclude that the increased risk of LGA observed following FET with artificial cycles may, at least partially, be associated with a confounding effect of some maternal factors. No information about embryo culture and incubation conditions was available. Most of the vitrification techniques were performed using the same device and with two main vitrification media, limiting the validity of a comparison of risk for LGA according to the device or vitrification media used. Our results seem reassuring, since no potential foetal growth disorders following embryo vitrification in comparison with slow freezing were observed. Even if other factors are involved, the endometrial preparation treatment seems to have the greatest impact on LGA risk following FET. FET during ovulatory cycles could minimize the risk for foetal growth disorders. This work has received funding from the French Biomedicine Agency (Grant number: 19AMP002). None of the authors has any conflict of interest to declare. N/A.

The “freeze-all” strategy seems to improve the chances of birth in adenomyosis-affected women

ObjectiveTo compare assisted reproductive technologies(ART) outcomes between fresh versus freeze-all strategies in infertile women affected with adenomyosis. DesignA single-center observational study SettingsUniversity hospital-based research center PatientsAdenomyosis-affected women undergoing blastocyst embryo transfer following in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) between 01/01/2018 and 31/11/2021. The diagnosis of adenomyosis was based on imaging criteria (i.e., transvaginal ultrasound and/or magnetic resonance imaging). Intervention(s)Women who underwent a freeze-all strategy were compared to those who underwent a fresh embryo transfer (ET) strategy.Main outcome measure(s): cumulative live birth rate (LBR) ResultsA total of 306 women were included in the analysis: 111 in the fresh ET group and 195 in the freeze-all group. The adenomyosis phenotype (internal diffuse adenomyosis, external focal adenomyosis, and adenomyoma) was not significantly different between the two groups. The cumulative LBR [86 (44.1%) vs. 34 (30.6%), respectively; p = 0.020] and the cumulative ongoing pregnancy rate [88 (45.1%) versus 36 (32.4%), respectively; p = 0.029] were significantly higher in the freeze-all group compared to the fresh ET group. After multivariate logistic regression analysis, the freeze-all strategy in women with adenomyosis was associated with significantly higher odds of live birth compared to fresh ET (OR = 1.80; 95% CI = 1.02–3.16). ConclusionThe freeze-all strategy in women afflicted with adenomyosis undergoing ART was associated with significantly higher cumulative live birth rates. Our preliminary results suggest that the freeze-all strategy is an attractive option that increase ART success rates. Additional studies, with a randomized design, should be conducted to further test whether the freeze-all strategy enhances the pregnancy rate in adenomyosis-affected women.

Association between the body mass index of women undergoing IVF and the gender of the offspring

Research questionIs there an association between women's body mass index (BMI) and the gender of offspring generated from fresh or frozen-thawed embryo transfer (FET) cycles? DesignBetween 2018 and 2021, 2670 cycles were performed, comprising 786 fresh embryo transfers and 1884 FET cycles. The study analysed the relationship between the BMI of women undergoing IVF and the sex of the newborn and the male-to-female live birth ratio (secondary sex ratio [SSR]). ResultsAfter 2670 single-embryo transfers, 483 (50.31%) male and 477 (49.69%) female infants were born, with an SSR of 101.3. In the fresh embryo transfer group, the SSR ranged from 350 (95% CI 82.67–1481.65) in underweight women (although this was based on very small numbers) to 109.7 (95% CI 67.73–176.61) in overweight women, while in the FET group, SSR values varied correspondingly from 130.8 (95% CI 64.47–265.26) to 63.0 (95% CI 46.02–86.24). Results from Bayesian multinomial logistic regression showed that for each unit increase in BMI within the fresh embryo transfer group, the odds of a boy's birth decreased by 6% (odds ratio [OR] 0.94, 95% CI 0.90–0.99) and the odds of a girl's birth by 5% (OR 0.95, 95% CI 0.90–0.99). Within the FET cohort, the odds of a boy's birth decreased by 4% (OR 0.96, 95% CI 0.92–0.99), while the odds of a girl's birth increased by 3% (OR 1.03, 95% CI 1.00–1.06). ConclusionsAn increase in BMI is associated with the birth of fewer boys in fresh or frozen embryo transfer cycles, and a significant increase in the birth of girls in FET cycles.

Pregnancy outcomes and disease phenotype of hypertensive disorders of pregnancy in singleton pregnancies after in vitro fertilization: a retrospective analysis of 1130 cases

BackgroundAlthough in vitro fertilization (IVF) can increase the incidence of hypertensive disorders of pregnancy (HDP), the pregnancy outcomes and disease phenotype of HDP in singleton pregnancies conceived via IVF remain unclear.MethodsThis retrospective cohort study enrolled 1130 singleton pregnancies with HDP from 2016 to 2020. According to the mode of conception, they were allocated into IVF (n = 102) and natural conception (NC) groups (n = 1028). All IVF pregnancies were subdivided into frozen embryo transfer (FET) group (n = 42) and fresh embryo transfer (ET) group (n = 60). Demographic data, pregnancy outcomes and disease phenotypes of HDP among the groups were compared. The risk factors for severe preeclampsia (PE) and early-onset PE were analyzed.ResultsThe incidences of early-onset PE (P<0.001), severe PE (P = 0.016), cesarean section (P<0.001) and preterm births (P = 0.003) in the IVF-HDP group were significantly higher than those in the NC-HDP group, and gestational age at diagnosis of HDP (P = 0.027) and gestational age at delivery (P = 0.004) were earlier and birthweight of the neonates (P = 0.033) were lower in the IVF group. In singleton pregnancies with HDP, IVF was associated with increased risks for both severe PE and early-onset PE (aOR 1.945, 95% CI 1.256, 3.014; and aOR 2.373, 95% CI 1.537, 3.663, respectively), as well as FET, family history of preeclampsia, intrahepatic cholestasis of pregnancy, gestational hypothyroidism and multiparity were associated with increased risks of severe PE and early-onset PE.ConclusionsIn singleton pregnancies with HDP, IVF was associated with an increased incidence of the disease phenotype (severe or early-onset PE), as well as an increased incidence of pregnancy outcomes related to severe PE and early-onset PE.

O-270 Does the ‘freeze all' strategy improve the chances of birth in the presence of adenomyosis?

Abstract Study question Does the freeze all strategy improve cumulative live birth rates in infertile women affected with adenomyosis? Summary answer The freeze all strategy in adenomyosis-affected women is associated with significantly higher cumulative live birth rates. What is known already Controlled ovarian stimulation enhances the efficacy of assisted reproductive technology (ART) by permitting multiple-oocyte yields, but also may alter endometrial receptivity by an earlier endometrial development which could in turn contribute to diminished pregnancy chances. Technical improvements in vitrification made deferred frozen-thawed embryo transfer (freeze –all strategy) a feasible alternative to fresh embryo transfer (ET). In adenomyosis, the eutopic endometrium is abnormal and its functional alterations are seen as likely to alter the quality of endometrial receptivity. One question in the adenomyosis ART-management is to know whether a freeze all strategy could lead to an increase in reproductive outcomes. Study design, size, duration This cohort study conducted in a tertiary care university hospital included adenomyosis-affected women undergoing blastocyst embryo transfer following in vitro fertilization / intracytoplasmic sperm injection (IVF/ICSI) between 01/01/2018 to 31/11/2021. The diagnosis of adenomyosis was based on imaging criteria (e.g. transvaginal ultrasound and/or magnetic resonance imaging). Participants/materials, setting, methods Women who underwent a freeze all strategy were compared to those who underwent a fresh ET strategy. Statistical analyses were conducted using univariate and multivariate logistic regression models. The primary outcome was the cumulative live birth rate (LBR). Main results and the role of chance A total of 306 women were included in the analysis: 111 in the fresh ET group and 195 in the freeze all group. The phenotype of adenomyosis (internal diffuse adenomyosis, external focal adenomyosis and adenomyomas) was not significantly different between the two groups. The cumulative live birth rate was significantly increased in the freeze all group compared to the fresh ET group [86 (44.1%) vs. 34 (30.6%), p = 0.020]. The cumulative OPR [89 (45.6%) versus 37 (33.3%), p = 0.035] and the cumulative CPR [122 (62.6%) vs. 53 (47.7%), p = 0.011] were significantly higher in freeze all group compared to the fresh group, whereas the early miscarriage rate was not significantly different between the two groups. After multivariate logistic regression analysis, the freeze all strategy in women with adenomyosis was associated with a significant increase in the live birth rate as compared to fresh ET (OR = 1.85; 95% CI = 1.06 – 3.24; p = 0.031). Limitations, reasons for caution This analysis consists in a retrospective cohort study. The inclusion of patients from a referral center specialized in the management of adenomyosis and endometriosis could constitute a selection bias, as these women may have had particularly severe forms of adenomyosis. Wider implications of the findings The freeze all strategy could be an attractive option to increase ART success rates, in adenomyosis-affected womenundergoing IVF/ICSI. Trial registration number NA

Fresh versus frozen embryo transfer in women with polycystic ovaries syndrome undergoing in vitro fertilisation

BackgroundPolycystic ovarian syndrome (PCOS) cases undergoing in vitro fertilisation (IVF) are widely at risk of ovarian hyperstimulation; therefore, elective freezing of all embryos to be transferred in a later cycle is preferred. We aimed to compare the pregnancy outcome between the fresh and the frozen embryo transfer (ET) in PCOS cases undergoing IVF with antagonist ovarian induction using human chorionic gonadotropin (HCG) as a trigger.MethodsIn this prospective randomised study, 110 infertile PCOS women underwent fresh ET (group A) or frozen ET (group B) with GnRH-antagonist protocol. The primary outcome was the chemical and clinical pregnancy rates. The secondary outcomes were the ongoing pregnancy rate, ovarian hyperstimulation syndrome (OHSS) rate, pregnancy loss rate, ectopic pregnancy rate, and congenital anomalies rate.ResultsThere was no significant difference between both groups regarding chemical pregnancy rate (44.23% vs 47.27%, P = 0.752), clinical pregnancy rate (42.31% vs 43.64%, P = 0.89), ongoing pregnancy rate (38.46% vs 41.82%, P = 0.723), pregnancy loss rate (17.39% vs 15.4%, P = 1), ectopic pregnancy rate (1.92% vs 0%, P = 0.486) and anomaly malformation rate (4.35% vs 3.85%, P = 1). On the other hand, the incidence of OHSS was significantly less in group B than in group A (3.64% vs 19.23%, P = 0.011), and the OHSS grade was less severe in group B than in group A (P = 0.033). However, there was no statistically significant difference between both regarding the need for hospitalisation (P = 0.111), ICU admission (P = 0.486), and ascites tapping (P = 0.486).ConclusionsUnder GnRH-antagonist protocol, frozen ET has the upper hand in PCOS undergoing IVF treatment for infertility, as it protects against OHSS and decreases its severity.Trial registrationIt was first registered at ClinicalTrials.gov on 22/12/2021 with registration number NCT05167838.

Comparison of uterine, endometrial and subendometrial blood flows in predicting pregnancy outcomes between fresh and frozen-thawed embryo transfer after GnRH antagonist protocol: a retrospective cohort study

This retrospective cohort study aimed to compare endometrial receptivity and pregnancy rate between fresh embryo transfer (ET) and frozen-thawed ET after gonadotrophin-releasing hormone (GnRH) antagonist protocol in normal ovarian responders. The patients were divided into two groups: the fresh ET group and the frozen-thawed ET group. Uterine artery resistance index (RI) and endometrial thickness were lower in the frozen-thawed ET group. The proportion of detectable endometrial–subendometrial flow was significantly higher in the frozen-thawed ET group. There was no significant difference in miscarriage rate between the two groups. Frozen-thawed ET group had a significantly higher CPR (56.0% vs. 48.1%), implantation rate (32.2% vs. 26.4%), and LBR (45.4% vs. 36.5%) than the fresh ET group. In GnRH antagonist protocol, elective frozen-thawed ET should be ideally taken, as this could improve embryo implantation rate, clinical pregnancy rate, and live birth rate, thus presenting an effective strategy to enhance the embryo utilization rate. IMPACT STATEMENT What is already known on this subject? The clinical pregnancy rate following fresh embryo transfer (ET) was lower than frozen-thawed ET after GnRH antagonist protocol. IVF success depends on embryo quality, embryo-endometrium interaction and endometrial receptivity. A good blood supply toward the endometrium is generally considered a requirement for implantation. What do the results of this study add? Uterine artery RI and endometrial thickness were significantly lower in the frozen-thawed ET group. The proportion of detectable endometrial–subendometrial flow was significantly higher in the frozen-thawed ET group. Frozen-thawed ET group had a significantly higher clinical pregnancy rate, implantation rate and live birth rate than the fresh ET group after GnRH antagonist protocol. What are the implications of these findings for clinical practice and/or further research? In GnRH antagonist protocol, elective frozen-thawed ET should be ideally taken, as this could improve embryo implantation rate, clinical pregnancy rate and live birth rate, thus presenting an effective strategy to enhance the embryo utilization rate.

Comparison of Pregnancy and Neonatal Outcomes Between Fresh Embryo Transfer and Frozen-Thawed Embryo Transfer.

This study compared the pregnancy and neonatal outcomes between fresh embryo transfer and frozen-thawed embryo transfer (FET). These patients were split into two groups: the fresh embryo transfer group and the FET group. The general conditions, pregnancy outcomes, and neonatal outcomes between these groups were compared. The influencing factors of fetal macrosomia occurrence were explored as well. Compared with the fresh embryo transfer group, the FET group had a significantly higher mean age (32.59 ± 4.77 vs. 31.90 ± 4.71, p < 0.05) and lower multiple pregnancy rate (21.2% vs. 26.9%, p < 0.05). There was no significant difference in the incidence of congenital anomalies of neonates between the two groups (1.32% vs. 0.37%, p > 0.05). In the FET group, compared with the fresh embryo transfer group, the mean birth weight of singleton live births, the cesarean section rate, and the incidence of fetal macrosomia were significantly increased, while the incidence of low birth weight was significantly decreased. The logistic analysis showed that the occurrence of fetal macrosomia was primarily associated with the embryo transfer protocol (odds ratio [OR] = 2.769, 95% confidence interval [CI]: 1.246-6.154, p < 0.05), endometrial thickness (OR = 1.144, 95% CI: 1.043-1.256, p < 0.05), and gestational age (OR = 1.710, 95% CI: 1.338-2.184, p < 0.05). Macrosomia (OR = 2.938, 95% CI: 1.436-6.010, p = 0.003) and multiple pregnancy (OR = 3.574, 95% CI: 2.616-4.882, p < 0.001) significantly increased the cesarean section rate. The risk of fetal macrosomia and congenital anomalies in the offspring of the fresh embryo transfer group was lower than that in the offspring of the FET group, we preferred to fresh embryo transfer for patients with assisted reproductive technologies. FET should be used as supplementary therapeutic strategy with strengthened pregnancy management and screening to reduce the occurrence of birth defects in newborns.

Comparing the effects of two different progesterone vaginal gels, Progeson™ and Crinone™, from pharmacokinetics study to clinical applications in patients undergone fresh embryo transfer and frozen-thawed embryo transfer via natural cycle endometrial preparation protocol.

The pharmacokinetics performance and clinical pregnancy rate of two vaginal progesterone gel, Progeson™ and Crinone™, were compared in this study. In the pharmacokinetics performance, Progeson showed similar long-term dissolution rate as Crinone. In the clinical study, 141 subjects undergone invitro fertilization (IVF) treatments were included to compare serum progesterone level and clinical pregnancy rates. Among the subjects, 78 subjects received fresh embryo transfer and 63 subjects received frozen embryo transfer via natural cycle endometrial preparation protocol. In each group, subjects were given either Crinone™ or Progeson™ for luteal phase support without combination with other progesterone products. The study showed that Crinone™ group led to higher estrogen level at mid-luteal phase in the fresh embryo transfer group, and Progeson™ group led to higher progesterone level at mid-luteal phase and pregnancy test day in the frozen-thawed embryo transfer group. Subjects received Crinone™ or Progeson™ had similar rate of pregnancy, live birth, and stillbirth in both fresh embryo transfer and frozen-thawed embryo transfer group. Thus, Progeson™ might be a suitable substitute for Crinone™ in assisted reproductive therapy.

Obstetric and perinatal outcomes following frozen and fresh embryo transfer in patients with endometrial hyperplasia and carcinoma: a retrospective study in a high-volume reproductive center

BackgroundThere is ongoing debate regarding which embryo transfer procedure can achieve a higher live birth rate. Research has suggested that frozen ET might be beneficial for certain populations, such as hyper-responders. This study aimed to compare outcomes of pregnancies between frozen and fresh embryo transfer cycles in patients with endometrial hyperplasia and carcinoma.MethodsThis retrospective cohort study was conducted at a high-volume reproductive center from January 2010 to January 2022. Patients who were diagnosed with endometrial hyperplasia with atypia and endometrial carcinoma were included. They all underwent in vitro fertilization after conservative treatment. The primary outcome was live birth after frozen and fresh embryo transfer cycles, and secondary outcomes included perinatal complications and other pregnancy outcomes.ResultsOverall, 259 ET cycles (130 fresh and 129 frozen) were included. The rate of live births per embryo transfer cycle of the whole cohort was 20.8% (54/259), and no significant between-group difference was found after adjusting for potential confounding factors (23.8% vs. 17.8%; adjusted OR, 0.47; 95% CI, 0.21-1.06; p=0.068). Compared to fresh embryo transfer group, the incidence of total maternal complications in the frozen embryo transfer group was significantly higher (30.4% vs. 6.5%, p=0.019). Analyzing each complication as a separate entity, patients in the frozen embryo transfer group had a higher incidence of hypertensive disorders of pregnancy (p=0.028). Multiple logistic regression analysis showed that frozen embryo transfer was related with an increased occurrence of maternal complications (OR, 6.68, 95% CI, 1.01-44.19, p=0.040).ConclusionsAmong patients with endometrial hyperplasia and carcinoma, the rate of live births was comparable between both embryo transfer procedures, while frozen embryo transfer might be associated with a higher risk of maternal complications compared to that with fresh embryo transfer.

Anthropometric measurements of term singletons at 6 years of age born from fresh and frozen embryo transfer: A multicenter prospective study in Japan.

The purpose of this study is to compare anthropometric measurements between term singletons conceived via fresh embryo transfer (FreET) and frozen embryo transfer (FET) and those born via natural conception (NC) or fertility treatments milder than assisted reproductive technology (non-ART) at 6 years of age. A total of 8149 children were enrolled, and questionnaires about anthropometric measures (weight, height, BMI) were addressed to parents, when the children were 1.5, 3, and 6 years of age. A total of 3299 term singletons were enrolled at birth: 533, 476, 916, and 1374 in the NC, non-ART, FreET, and FET groups, respectively. A total of 1635 term singletons (290, 176, 467, and 702 in the NC, non-ART, FreET, and FET groups respectively) were enrolled until 6 years of age (follow-up rate, approximately 50%). When non-ART group was used as control, the FreET children were 1.0cm taller than the non-ART children at 6 years of age, after adjusting for confounding factors. However, no differences were observed in the anthropometric data among the non-ART, ART, and NC children at 6 years of age. At 6 years of age, term singletons were taller in the FreET group than in the non-ART group, after adjusting for confounders.