Frozen-thawed Embryo Transfer Cycles Research Articles

Perinatal outcomes of frozen-thawed embryo transfer following blastocyst-stage embryo transfer compared to those of cleavage-stage embryo transfer: analysis of 9408 singleton newborns using propensity score analysis

Objective: Regarding frozen-thawed embryo transfer (FET), there is limited consensus on whether extending embryo culture from the cleavage stage to the blastocyst stage affects perinatal outcomes. This study aimed to compare perinatal outcomes of singletons between blastocyst-stage embryo transfer (BT) and cleavage-stage embryo transfer (CT) in FET. Methods: A total of 9408 FET cycles that met the inclusion criteria were included in this retrospective cohort study between 2019 and 2022. Blastocyst-stage embryo transfers were performed in the BT group, and cleavage-stage embryo transfers were performed in the CT group. Multivariate logistic regression analyses were performed, as well as propensity score matching (PSM) to adjust for confounders. Results: After PSM, a higher risk of pre-term birth (PTB; odds ratio [OR]: 1.23, 95% confidence interval [CI]: 1.00–1.50, P = 0.048) and being large for gestational age (LGA; OR: 1.16, 95% CI: 1.00–1.35, P = 0.050) was observed in the BT group compared to that in the CT group. After stratified PSM, in the subgroup under 35 years of age, only an increased risk of LGA was observed in the BT group compared to the CT group. Perinatal outcomes in the double-embryo transfer subgroup were similar to those in the unstratified group. However, in the subgroup beyond 35 years of age and the single embryo transfer subgroup, perinatal outcomes were not statistically different between the BT and CT groups (P >0.05). Conclusions: In FET, prolonged embryo culture to the blastocyst stage increased the risk of PTB and LGA in single fetuses. However, stratified analysis based on age and the number of transferred embryos yielded different results, necessitating further mechanistic studies.

Higher pre-pregnancy body mass index was associated with adverse pregnancy and perinatal outcomes in women with polycystic ovary syndrome after a freeze-all strategy: Ahistorical cohort study.

Previous studies have demonstrated that abnormal body mass index (BMI) is associated with adverse pregnancy outcomes in frozen-thawed embryo transfer cycles. However, the relationship between BMI and pregnancy and perinatal outcomes in patients with polycystic ovary syndrome (PCOS) remains unclear. Furthermore, whether a diagnosis of PCOS could result in adverse pregnancy and perinatal outcomes in women with different BMIs remains unknown. A historical cohort study included 1667 women with PCOS and 12 256 women without PCOS after a freeze-all policy between January 2016 and December 2020. The outcomes encompassed both pregnancy and perinatal outcomes. Multivariate logistic regression analysis and restricted cubic spline models were performed to eliminate confounding factors when investigating the relationship between BMI and different outcomes. After controlling for covariates, pregnancy outcomes were comparable between underweight women with PCOS and normal weight women with PCOS. However, overweight patients had a lower clinical pregnancy rate and an overall live birth rate. Furthermore, patients with obesity had a lower rate of multiple pregnancies but a higher rate of biochemical pregnancy than in the normal BMI group. Additionally, the restricted cubic spline models showed that as maternal BMI increased to 32 kg/m2, the clinical pregnancy rate and live birth rate after blastocyst transfer decreased, but the risks of preterm birth, gestational diabetes mellitus, macrosomia, large-for-gestational age (LGA) and very LGA increased in patients with PCOS after a freeze-all strategy. Moreover, a diagnosis of PCOS resulted in a higher clinical pregnancy rate and live birth rate and a higher risk of small-for-gestational age in the normal weight group. However, women with PCOS in the overweight group exhibited higher risks of very preterm birth and gestational diabetes mellitus compared with women without PCOS. This study showed that a higher BMI had a detrimental impact on the pregnancy and perinatal outcomes of PCOS patients undergoing a freeze-all strategy. However, it was only statistically significant in the overweight group. A diagnosis of PCOS had a higher clinical pregnancy rate and live birth rate in normal weight women but higher risks of perinatal complications in normal weight and overweight women.

Luteal phase support of intramuscular progesterone associated with lower hypertensive disorders of pregnancy as compared to vaginal progesterone: A cohort study.

To compare the hypertensive disorders of pregnancy (HDP) risk between vaginal and intramuscular (IM) progesterone in programmed frozen-thawed embryo transfer (FET) cycles. This was a retrospective cohort study at a tertiary hospital, and only women who achieved ongoing pregnancy after programmed FET between January 2018 and June 2022 were included. Women with chronic hypertension before pregnancy or with history of gestational hypertension or pre-eclampsia in previous pregnancies were excluded. All women were divided into IM progesterone or vaginal progesterone groups according to the route of progesterone supplementation. Follow-up information on obstetric complications and neonatal outcomes were obtained by telephonic interviews. The primary outcome was HDP. Association between routes of progesterone supplementation and HDP was assessed by subgroup analysis and multivariable logistic regression. A total of 5891 programmed FET cycles (3196 IM progesterone cycles and 2695 vaginal progesterone cycles) were included in the analysis. The prevalence of HDP in the IM progesterone group was significantly lower than that of the vaginal progesterone group (6.54% vs 9.17%, P < 0.001). Therein, the prevalence of gestational hypertension (3.57% vs 4.94%, P = 0.009) and pre-eclampsia (2.97% vs 4.23%, P = 0.009) in the IM progesterone group were all significantly lower as compared to the vaginal progesterone group. According to subgroup analysis, IM progesterone was associated with lower HDP risk in all subgroups. The logistic regression analysis showed that the IM progesterone cycles were associated with lower risk of HDP compared to vaginal progesterone cycles (adjusted odds ratio 0.66, 95% CI: 0.54-0.80, P < 0.001). Among women undergoing programmed FET cycles, progesterone supplementation with IM progesterone was associated with reduced HDP risk compared to vaginal progesterone.

Effect of paternal body mass index on maternal and child-health outcomes of singletons after frozen-thawed embryo transfer cycles: a retrospective study

The objective was to analyze the effect of paternal body mass index (BMI) on maternal and child-health outcomes of singletons after frozen-thawed embryo transfer (FET) cycles. A retrospective cohort study was conducted between January 2019 and December 2021. Pregnancy, perinatal complications and neonatal outcomes were compared among different paternal BMI. Multivariate logistic regression was performed to evaluate the relationship between different paternal BMI and pregnancy, obstetric and neonatal outcomes. The paternal normal group was more likely to suffer from gestational hypertension than the paternal obesity group (3.59% vs. 2.42%), and paternal underweight group was more likely to suffer from preeclampsia than the other three groups (11.63% vs. 4.43%, 7.57%, 4.03%). Birthweight among infants in the paternal overweight categories was significantly higher than infants in the paternal normal weight categories. The rate of foetal macrosomia was higher among infants in the paternal overweight (12.36%) category, while lower among infants in the paternal underweight categories (2.33%). The incidence of macrosomia in the paternal overweight categories (aOR 1.527, 95% CI 1.078–2.163) was significantly higher than those normal controls after adjustment for known confounding factors. The rates of LGA babies were higher in the paternal overweight category (aOR 1.260, 95% CI 1.001–1.587) compared with those in the paternal normal weight category, before and after adjustment. The results suggest that parental pre-pregnancy overweight or obesity has an adverse effect on the perinatal complications and neonatal outcomes.

Atosiban interacts with growth hormones as adjuvants in frozen-thawed embryo transfer cycles.

To investigate the interaction between atosiban and growth hormone (GH) as adjuvants in frozen-thawed embryo transfer (FET) cycles. A total of 11627 patients who underwent FET at Xiamen University Affiliated Chenggong Hospital between January 2018 to December 2022 were retrospectively analyzed. Among them, 482 patients received atosiban and 275 patients received GH. The interactions were estimated by comparing the odds ratio (OR) for pregnancy comparing patients with or without atosiban adjuvant in cohorts stratified according to the presence of GH use in either the overall cohort or a propensity score (PS) matched cohort. An interaction term (atosiban × GH) was introduced to a multivariate model to calculate the ratio of OR (ORR) adjusted for confounders. For all patients receiving atosiban administration, no obvious effect on pregnancy was observed in comparison with either matched or unmatched controls. However, when the patients were stratified according to GH administration, atosiban showed a significant association with clinical pregnancy in comparison with either matched or unmatched controls among patients with GH treatment with rate ratios (RR) of 1.32 (95%CI: 1.05,1.67) and 1.35 (95%CI: 1,1.82), respectively. On the other hand, however, the association was absent among patients without GH treatment. The adjusted ORRs in both matched and unmatched cohorts were 2.44 (95%CI: 1.07,5.84) and 1.95 (95%CI: 1.05, 3.49) respectively. The combination use of atosiban and GH in FET cycles is potentially beneficial to the pregnancy. However, indications for the use of atosiban and GH may need further assessment.

Neutral effect of Zishen Yutai Pill on frozen-thawed embryo transfer: a propensity score matching study.

To investigate whether using Zishen Yutai Pills (ZYP) following embryo transfer would affect the live birth rate in frozen-thawed embryo transfer (FET) cycles. A retrospective analysis was performed on 15044 FET cycles in the Reproductive Medicine Center of The Affiliated Chenggong Hospital of Xiamen University from January 2013 to December 2020. Patients who used Zishen Yutai Pills were defined as Zishen Yutai Pills Group (ZYP, n=2735), while patients who did not use them were defined as Non- Zishen Yutai Pills Group (Non-ZYP, n=12309). The propensity score matching method was used to control for potential confounders between the two groups, and logistic regression analysis was also used to assess whether using ZYP would affect the live birth rate. After propensity score matching, basic characteristics were similar between the two groups. Using ZYP did not increase the pregnancy rate (51.5% vs. 52.7%, P=0.372), and live birth rate (43.0% vs. 44.7%, P=0.354). This was also confirmed by the logistic regression analysis results (OR=0.95, 95%CI=0.85-1.06). In the subgroup analysis of the endometrial preparation protocols, however, it was found that the use of ZYP in patients with natural cycles increased the live birth rate (47.4% vs. 41.5%, P=0.004). A significant interaction between endometrial preparation and ZYP was found (OR=1.38, 95%CI=1.07-1.79) in the multivariate model. The use of ZYP may not improve the live birth rate of unselected patients in FET cycles. However, a future study is needed on the effect of ZYP in natural cycles for endometrial preparation.

The association between pregnancy outcomes and frozen-thawed embryo transfer cycles based on D3 cell count in high-quality blastocysts.

To investigate the number of cells in D3-stage embryos of high-quality blastocysts as a contributing factor, to evaluate the clinical pregnancy outcomes in frozen-thawed embryo transfer cycles, and to determine the impact of D3-stage cell count on pregnancy outcomes. Patients under 38 years old who underwent frozen-thawed single high-quality blastocyst transfer at our center were selected. Based on the cell count of D3 cleavage-stage embryos forming blastocysts, patients were divided into three groups: ≤6 cells, 7-9 cells, and ≥10 cells. A multivariate regression analysis was used to establish the prediction model, analyzing the impact of different D3 cleavage-stage cell counts on clinical pregnancy outcomes to guide clinical laboratories in selecting blastocysts with the best pregnancy outcomes for transfer. This study identified a significant association between D3 cell count, blastocyst development stage, and embryo age. Embryos with a higher D3 cell count (≥10) were more likely to reach advanced blastocyst stages and form blastocysts by D5, whereas embryos with fewer D3 cells (≤6) were more likely to form blastocysts on D6. While D3 cell count significantly influenced blastocyst stage and timing of embryo development, no significant differences were observed between groups regarding clinical pregnancy, implantation, or live birth rates. Notably, embryos with fewer D3 cells exhibited a significantly lower miscarriage rate than other groups. Multivariate regression analysis showed a significant correlation between blastocyst stage, embryo age, and D3 cell count, particularly in D5 embryos and more advanced blastocysts. The increased miscarriage rate may be related to lower D3 cell count, and inadequate endometrial preparation was associated with poorer pregnancy outcomes. The type of infertility was also linked to D3 cell count, with secondary infertility patients showing more significant influencing factors. D3 cell count and related factors play a critical role in pregnancy outcomes during frozen-thawed high-quality blastocyst transfer cycles. Optimizing embryo age, selecting blastocysts at different stages, and refining endometrial preparation protocols are likely to enhance clinical pregnancy and live birth rates.

The effect of single dose of gonadotropin-releasing hormone agonist injection in frozen-thawed embryo transfer on pregnancy outcomes: A systematic review and meta-analysis.

This systematic review and meta-analysis of randomized controlled trials aimed to evaluate the effect of a single-dose gonadotropin-releasing hormone agonist administration in the frozen-thawed embryo transfer cycle on pregnancy outcomes. A literature search was strategically conducted using PubMed, EMBASE, and the Cochrane Controlled Trials Register. The primary outcome was the clinical pregnancy rate. The secondary outcomes combined chemical pregnancy rate, implantation rate, ongoing pregnancy rate, live birth rate, miscarriage rate, and extrauterine pregnancy rate. Out of the 1594 citations that were found, only six met the criteria for being included in the meta-analysis. The clinical pregnancy rate was higher in the treatment group than in the control group (52.05% vs. 47.29%; p=0.04; RR=1.09; 95% CI=1.00-1.18). According to subgroup analysis based on the natural cycle, the clinical pregnancy rate with the agonist administration is significantly higher (43.75% vs. 27.35%; p=0.01; RR=1.6; 95% CI=1.10-2.32). However, there was no difference between the groups in terms of artificial cycles (p=0.80; 95% CI=0.96-1.20). The secondary outcomes did not show significant differences. We concluded that supplementing with a single dose of gonadotrophin-releasing hormone agonist can marginally increase the clinical pregnancy rate, particularly in the natural cycle. Other pregnancy outcomes do not improve with the treatment.

Pretreatment with long-acting gonadotropin-releasing hormone agonists improved pregnancy outcomes after hysteroscopic multiple polypectomies: A retrospective study of 660 frozen–thawed embryo transfer cycles

ObjectiveTo compare the reproductive pregnancy outcomes of pretreatment with long-acting gonadotropin-releasing hormone agonist (GnRH-a) plus hormone replacement therapy (HRT) with HRT-only cycles, and investigate differences between single polypectomy and multiple polypectomies, and between one or two doses of GnRH-a. Materials and methodsThis was a retrospective cohort study on patients undergoing polypectomy who underwent frozen–thawed embryo transfer (FET) from March 2018 to May 2019. They were divided into GnRH-a pretreatment and HRT-only groups. Each group was divided into single polypectomy or multiple polypectomies (in a single hysteroscopic session) subgroups. Clinical pregnancy rate and live birth rate (LBR) were the main outcomes. The effect of GnRH-a dosage was further analysed. ResultsThere were 212 GnRH-a pretreatment cases (45 single and 167 multiple polyps) and 448 HRT-only cases (228 single and 220 multiple polyps). The LBR of the GnRH-a pretreatment group (53.3%) was significantly higher than the HRT group (43.3%; P = 0.016). Logistic regression analysis showed that GnRH-a pretreatment significantly affected the LBR (odds ratio, OR 1.470, 95% confidence interval, Cl 1.046–2.065; P = 0.026). In the multiple polypectomy subgroup, the LBR with GnRH-a pretreatment was higher than with HRT-only (54.5% vs 43.6%; P = 0.034). However, the LBR was not different between the respective single polypectomy subgroups (48.9% vs 43.0%; P = 0.466). For patients with multiple polyps, two GnRH-a pretreatments produced a higher LBR than a single GnRH-a pretreatment (62.7% vs 47.8%), but without significant difference (P = 0.055). ConclusionGnRH-a pretreatment improved the LBR for FET cycles after hysteroscopic multiple polypectomies, independent of dose.

Pregnancy outcomes after frozen-thawed embryo transfer in women with COVID-19 history: A prospective cohort study.

The clinical effect ofCoronavirus disease 2019 (COVID-19)on endometrial receptivity and embryo implantation remains unclear. Herein, we aim to investigate whether a COVID-19 history adversely affect female pregnancy outcomes after frozen-thawed embryo transfer (FET). This prospective cohort study enrolled 230 women who underwent FET cycles from December 2022 to April 2023 in an academic fertility center. Based on the history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection before FET, women were divided into the infected group (n = 136) and the control group (n = 94). The primary outcome was the clinical pregnancy rate per cycle. Multivariate logistic regression analysis was conducted to adjust for potential confounders, while subgroup analysis and restricted cubic splines were used to depict the effect of postinfection time interval on FET. The results showed that the clinical pregnancy rate was 59.6% in the infected group and 63.9% in the control group (p = 0.513). Similarly, the two groups were comparable in the rates of biochemical pregnancy (69.1% vs. 76.6%; p = 0.214) and embryo implantation (51.7% vs. 54.5%; p = 0.628). After adjustment, the nonsignificant association remained between prior infection and clinical pregnancy (OR = 0.78, 95% CI: 0.42-1.46). However, the odds for clinical pregnancy were significantly lower in the ≤30 days subgroup (OR = 0.15, 95% CI: 0.03-0.77), while no statistical significance was detected for 31-60 days and >60 days subgroups compared with the uninfected women. In conclusion, our findings suggested that SARS-CoV-2 infection in women had no significant effect on subsequent FET treatment overall, but pregnancy rates tended to be decreased if vitrified-thawed embryos were transferred within 30 days after infection. A 1-month postponement should be rationally recommended, while further studies with larger sample groups and longer follow-up periods are warranted for confirmation.

The number of previous implantation failures is a critical determinant of intrauterine autologous platelet-rich plasma infusion success in women with recurrent implantation failure.

We aimed to identify factors influencing the reproductive outcomes of frozen-thawed embryo transfer (FET) with intrauterine autologous platelet-rich plasma (PRP) infusion in patients with either a thin endometrium or recurrent implantation failure (RIF) despite a normal endometrial appearance. In this retrospective study of women who underwent PRP-FET, factors influencing PRP-FET outcomes were identified using multivariate logistic regression analysis. We enrolled 111 patients (70 with refractory thin endometrium and 41 with RIF but no thin endometrium). For 99 completed FET cycles, the β-hCG positivity rate was 46.7%, clinical pregnancy rate (CPR) was 41.0%, and live birth rate (LBR) was 36.2%. PRP treatment was associated with significant improvements over previous cycles, and participants with thin endometria demonstrated thickening. Multivariate logistic regression analysis showed that the number of previous implantation failures in women with RIF was a significant factor affecting the PRP-FET outcomes. The CPR and LBR of women with RIF were lower when there had been ≥3 previous implantation failures occurred. Intrauterine PRP infusion improves the pregnancy outcomes of patients with RIF or a thin endometrium. The number of previous implantation failures is a critical determinant of successful intrauterine PRP infusions in women with RIF.

Assisted reproductive technology in Japan: A summary report for 2021 by the Ethics Committee of the Japan Society of Obstetrics and Gynecology.

The Japan Society of Obstetrics and Gynecology (JSOG) registry gathers comprehensive data from registered assisted reproductive technology (ART) facilities in Japan. Herein, we report 2021 ART cycle characteristics and outcomes. Descriptive statistics were used to summarize and analyze 2021 data. In 2021, 625 ART facilities participated in the registry; 27 facilities did not conduct ART cycles and 598 registered treatment cycles. In total, 498 140 cycles were registered, and there were 69 797 neonates (increases of 10.7% and 15.5%, respectively, from the previous year). The number of freeze-all invitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) cycles decreased in 2021; the number of neonates born was 2268 for IVF-embryo transfer (ET) cycles and 2850 for ICSI cycles. Frozen-thawed ET (FET) cycles increased markedly from 2020 (11.2% increase). In 2021, 239 428 FET cycles were conducted, resulting in 87 174 pregnancies and 64 679 neonates. For fresh transfers, the total single ET, singleton pregnancy rate, and singleton live birth rates were 82.7%, 97.0%, and 97.3%; for FET, these rates were 84.9%, 96.9%, and 97.1%. The 2021 Japanese ART registry analysis showed marked increases in both total treatment cycles and live births from the previous year.

The impact of transferred air bubble position on clinical pregnancy rate in FET cycles.

We aim to investigate the correlation of the position of the transferred air bubble with the clinical pregnancy rate (PR) in frozen-thawedembryo transfer(FET) cycles. A prospective clinical study was carried out at Reproductive medicine center of West China Second University Hospital between June 2020 and May 2021. 1159 women underwent FET were included in this study. Transabdominal ultrasonographic guidance was used during the transfer procedure. The distance from the air bubble to endometrial cavity fundus（DAF）was measured in the freeze-frame ultrasound immediately after ET. In group DAF ≤3mm, 3-15mm and ≥15mm, the clinical PR in women transferred with cleavage embryos were 33.3% (7/21), 55.0% (153/280), and 31.3% (5/16), respectively, the difference was statistically significant (P＜0.05). Among women transferred with blastocysts, the clinical PR was 63.0% (34/54), 68.5% (485/708) and 55.0% (44/80), respectively, the difference was statistically significant (P＜0.05). In multivariate logistic regression model for clinical PR, the clinical PR was associated with age, embryo quality, number of embryo transferred, and endometrial thickness. DAF was an independent risk factor influencing clinical PR in blastocysts FET cycles rather than in cleavage embryos FET cycles.In conclusion, our results suggested that DAF was associated with the clinical PR and DAF between 3mm and 15mm is the optimal position in blastocysts FET cycles.

#276 : Impact of Previous Cesarean Delivery on Pregnancy and Neonatal Outcomes of Subsequent In Vitro Fertilization/Intracytoplasmic Sperm Microinjection and Single Frozen-Thawed Embryo Transfer

Background and Aims: Cesarean delivery (CD) rates continue to rise worldwide. Prior studies have indicated that CD is associated with not only various gynaecological symptoms and obstetric complications but also lower probability of subsequent fertility. However, the recognition about impact of CD on clinical outcomes in subsequent IVF/ICSI-FET is very limited. The purpose was to investigate the effects of previous CD on pregnancy and neonatal outcomes in single frozen-thawed embryo transfer (FET) cycles so that women with a previous cesarean delivery can be given detailed fertility counseling during the ART process. Methods: This is a large retrospective cohort study including a total of 5,750 patients who desired to transfer single vitrified-thawed blastocyst from the same oocyte retrieval cycle as their last live birth between January 2011 and January 2021 in a center for reproductive medicine in Shandong, China, comprising FET cycles of 3,853 previous single CD and 1,897 previous single vaginal delivery (VD). Results: Women with a previous CD had significantly lower rates of biochemical pregnancy (64.52% vs. 71.48% before propensity score matching (PSM), P&lt;0.001; and 65.58% vs. 71.49% after PSM, P&lt;0.001), clinical pregnancy (58.16% vs. 65.79% before PSM, P&lt;0.001; and 59.22% vs. 66.17% after PSM, P&lt;0.001) and live birth (48.17% vs. 55.82% before PSM, P&lt;0.001; and 49.29% vs. 56.10% after PSM, P&lt;0.001) than those with a previous VD. Meanwhile, the CD rate was significantly higher in the CD group (97.85% vs. 18.53% before PSM, P&lt;0.001; and 98.02% vs. 20.51% after PSM, P&lt;0.001). The rates of multiple pregnancy, miscarriage, ectopic pregnancy, multiple live birth, labor complications and preterm and neonatal outcomes were comparable between the two groups. Conclusion: Compared to VD, a previous CD is associated with a significant reduction in the rates of biochemical pregnancy, clinical pregnancy and live birth in patients undergoing subsequent single frozen-thawed blastocyst transfer.

#113 : Transdermal Oestrogen (GEL) for Endometrial Preparation in Frozen-Thawed Embryo Transfer

Background and Aims: Frozen-thawed embryo transfer (FET) requires a synchronization between endometrium and embryo. Pregnancy and live birth rates are proven to be significantly higher with FET due to better endometrial receptivity. In this study, we look at effectiveness oftwo oestrogen preparations in hormone replacement therapy (HRT) FET cycle on the pregnancy outcomes. Method: This is a retrospective analysis of 200 HRT FET cycles from 1st Jan 2020-31st December 2021, divided into 2 groups. Group 1 (n=100) received T Progynova 6 mg/day and Group 2 (n=100) received Oestrogel 6 mg/day (17B oestradiol 0.06% gel Besins France) starting on day 1 of menses, without GnRH agonist pituitary downregulation. The oestrogen dose was adjusted accordingly to achieve endometrial thickness (ET) of minimum 8 mm, prior to initiation of vaginal progesterone. The pregnancy outcomes (biochemical pregnancy, clinical pregnancy, ongoing pregnancy, early pregnancy loss and ectopic pregnancy rates), duration of oestrogen usage and endometrial thickness measurement prior to embryo transfer were analysed. Results: The biochemical pregnancy rate in this study was 39%, with a clinical pregnancy rate of 31%. Comparing both preparations, the biochemical pregnancy rate (p=0.562), clinical pregnancy rate (p=0.705), ongoing pregnancy rate (p=0.623), and early pregnancy loss rate (p=0.705) were not statistically significant. The duration required to achieve optimal endometrial thickness (p=0.212), and endometrial thickness measurement prior to vaginal progesterone commencement (p=0.335) were comparable. Conclusion: Oestrogel is a non-inferior option to oestradiol valerate for endometrial preparation in HRT FET cycles, especially for patients with high risk of venous thromboembolism due to its safety profile.

#82 : Does Apoptotic Body Impair Pregnancy Outcome

Background: Morphologically suboptimal blastocyst is often associated with poorer pregnancy outcomes. Apoptotic body is one of the abnormal findings in blastocysts characterised by cellular shrinkage and a darker appearance. The presence of apoptotic bodies may be suggestive of ongoing cellular degeneration. Cellular degeneration in the blastocyst is part of its self-corrective mechanism. The degenerated cells will deplete through the phagocytosis process. Aims: This is a retrospective study that aims to analyse whether the presence of apoptotic body has a significant impact on pregnancy outcomes. Method: We compare the outcome of the frozen-thawed embryo transfer (FET) cycle of blastocysts with apoptotic body and without it as a control. We further divide the cases into single blastocyst transfer and double blastocyst transfer. The data was collected from Vistana Fertility Centre from January to December 2022. Results: Conclusion: Data analysis showed that there is no significant difference between the study group and the control group. Hence, the presence of dead cells did not negatively impact the pregnancy outcomes.

First 15 Years of Assisted Reproductive Technology Using Washed Sperm in HIV-Positive Individuals Under Antiretroviral Therapy: Sweden's Nationwide Outcomes.

Antiretroviral therapy has made HIV a chronic infectious disease. In Sweden, assisted reproductive technologies using sperm washing were implemented in 2004 for treatment of all HIV-positive males in serodiscordant couples at Karolinska Hospital in Stockholm. This study aimed to assess efficacy and safety of this approach and to investigate the effect of antiretroviral regimens on sperm quality of men treated for HIV. The study included all HIV-positive men (n = 53) adherent to antiretroviral treatment, including nucleoside/nucleotide analog reverse-transcriptase inhibitors (NRTIs) combined with non-nucleoside reverse-transcriptase inhibitors (NNRTIs) in 22 cases, or with other medication in 31 cases wishing fertility treatment. Sperm was washed using gradient centrifugation with a double tube system, frozen and thawed. Thereafter, single spermatozoa were injected in oocytes by intracytoplasmic sperm injection (ICSI). Treatment outcomes were compared to those of hepatitis B virus (HBV)-seropositive men in serodiscordant couples (n = 56), undergoing similar sperm washing protocols and ICSI at the center. In total, 82 fresh and 39 frozen/thawed embryo transfer (FET) cycles were performed in discordant HIV couples and 92 fresh and 36 FET cycles in HBV. Fertilization rates (69.2% vs. 64.6%, p = 0.310), clinical pregnancy rates (39.2% vs. 32.6%, p = 0.378), and live birth rates (35.8% vs. 31.5%, p = 0.565) were similar between the groups and the cumulative results yielded similar outcomes with a live birth rate of 52.8% and 51.8% (p = 0.913), respectively. No post-wash sperm sample was found positive for HIV viral particles. No partner seroconversion or offspring infection was reported. NNRTI-treated men had significantly lower motile sperm concentration than non-NNRTI-treated patients (54.48% vs. 36.41%, p < 0001). This study showed that in vitro fertilization/ICSI treatment with sperm washing was safe in individuals compliant to antiretroviral treatment and the reproductive outcome was similar to that of HBV-positive men. The observed moderate negative impact on sperm motility of NNRTI regimens may be overcome by using ICSI.

Association between endometrial thickness and birthweight of singletons from vitrified-warmed cycles: a retrospective cohort study

Research questionWhat is the association between endometrial thickness (EMT) and the birthweight of singleton infants born from frozen-thawed embryo transfer cycles? DesignThis retrospective cohort study was conducted from January 2016 to December 2019. Participants were categorized into a natural cycle (NC, n = 8132) group and hormone replacement therapy (HRT, n = 4975) group. Only singleton deliveries were included. The primary outcomes were measures of birthweight and relevant indexes. Multivariable logistic regression and multivariable-adjusted linear regression models that incorporated restricted cubic splines were used. ResultsIn the HRT group, the risk of delivering a small for gestational age (SGA) infant was increased in women with an EMT <8.0 mm (adjusted odds ratio [aOR] 1.85, 95% confidence interval [CI] 1.17–2.91) compared with women with an EMT of 8.0 to <12.0 mm, and increased with an EMT ≥12.0 mm (aOR 1.85, 95% CI 1.03–3.33). An inverted U-shaped relationship was found between EMT and birthweight in women with HRT. No significant differences were shown in birthweight z-score, or being SGA or large for gestational age, in singletons among the three EMT groups in the natural cycles. ConclusionsA thinner endometrium seen in women undergoing HRT cycles was associated with a lower birthweight z-score, as well as a higher risk of SGA. However, no significant association was observed between EMT and birthweight z-score or SGA in the NC group. It is noteworthy that a thicker endometrium was not associated with a higher birthweight in frozen-thawed embryo transfer (FET) cycles. Women with a thin endometrium who achieve pregnancy require specialized attention, particularly if they are undergoing FET with HRT cycles.

Association of serum progesterone levels on the transfer day with pregnancy outcomes in hormone replacement frozen-thawed cycles with oral dydrogesterone for strengthened luteal phase support

ObjectiveTo investigate the relationship between serum progesterone (P) levels on the day of blastocyst transfer and pregnancy outcomes in frozen-thawed embryo transfer (FET) cycles using hormone replacement therapy (HRT) with oral dydrogesterone for strengthened luteal phase support (LPS). Materials and methodsThis was a retrospective study including 1176 FET cycles. All patients received 40 mg of intramuscular (IM) P daily for endometrium transformation plus oral dydrogesterone 10 mg BID from transfer day for strengthened LPS. Pregnancy outcomes were compared between serum P levels on the transfer day ≥10 ng/ml and <10 ng/ml. Furthermore, cycles were divided into 10 groups by deciles of P and ongoing pregnancy rate (OPR) was calculated in each group. Analyses using deciles of serum P were completed to see if these could create further prognostic power. ResultsNo differences were observed in clinical pregnancy rates (CPRs), OPRs and live birth rates (LBRs) between serum P levels ≥10 ng/ml and <10 ng/ml. Patients with serum P levels <5.65 ng/ml (10th percentile) had a significantly lower OPR (48.31% vs. 58.98%, p = 0.03) and LBR (43.22% vs. 57.75%, p = 0.003) than the rest of the patients. Multivariate logistic regression analysis showed serum P levels on the transfer day were not associated with pregnancy outcomes. ConclusionMeasuring serum P levels on the day of HRT-FET is of clinical importance. Lower serum P levels impact the success of HRT-FET cycles, suggesting that there may be a threshold below which it is difficult to improve pregnancy outcomes via oral dydrogesterone to strengthen LPS.

Stratified analysis of clinical pregnancy outcomes of sequential embryo transfer in frozen embryo transfer cycles based on different factors: a retrospective study

ObjectiveTo explore the effect of sequential embryo transfer (ET) on the pregnancy outcome of frozen-thawed embryo transfer (FET) cycle and the indications of sequential transfer.MethodsA total of 1440 FET cycles were enrolled in this retrospective study, of which 1080 patients received conventional ET and 360 patients received sequential ET. Further stratified analysis was performed according to the number of previous failed cycles, the number of embryos transferred and the stage of blastocyst (day 5 or 6, denoted D5 or D6) transferred. Comparison of pregnancy rates, implantation rate, miscarriage rate and multiple pregnancy rate among the groups of patients.ResultsThe clinical pregnancy rate and implantation rate of the sequential ET group were higher than those of the conventional ET group (P < 0.01); however, there was no statistical difference in multiple pregnancy rate and miscarriage rate (P > 0.05). In sequential transfer, the number of transferred embryos (2 or 3) and the stage of transferred blastocysts (D5 or D6) had no effect on clinical pregnancy rate, implantation rate, multiple pregnancy rate and miscarriage rate (P > 0.05). In patients with three or more previous failure cycles, the sequential ET group showed higher clinical pregnancy rate and implantation rate (P > 0.05).ConclusionsCompared with conventional ET in FET cycle, sequential ET strategy could significantly improve the clinical pregnancy rate and implantation rate. In sequential transfer, patients with three embryos transferred don’t have higher pregnancy rate and implantation rate. Besides, sequential transfer is more suitable for patients with repeated implantation failures (RIF), and increase the utilization rate of D6 blastocysts.