Does the sex ratio of singleton births after frozen single blastocyst transfer differ in relation to blastocyst development?

PURPOSE: To investigate the associations between blastocyst development and the sex ratio (male:female) among singleton live births resulting from single-blastocyst frozen embryo transfer (FET) cycles. METHODS: Patients with singleton live births following the first autologous single FET of non- preimplantation genetic testing (PGT) blastocysts in a single reproductive medicine department between January 2015 and February 2019 were included in this retrospective study. The primary outcome measure was the singleton sex ratio. Multivariable logistic regression models were used to estimate the associations between blastocyst quality and singleton sex ratio after adjustment for some potential confounders. RESULTS: There were 638 high-quality and 572 poor-quality single blastocyst FETs, and the blastocysts were conceived via 855 IVF and 355 ICSI treatments. A total of 1210 singleton live births were assessed. High-quality single blastocyst FET resulted in a significantly higher sex ratio than did poor-quality single blastocyst FET (60% vs. 49.7%, P < 0.001). The infertility cause was not associated with sex ratio among singleton live births (P = 0.537). The results of a multivariate analysis revealed that a high-quality blastocyst has a 150% higher probability of being male than a poor-quality blastocyst (adjusted odds ratio (aOR) 1.57; 95% CI 1.24-2, P < 0.001). Among the three blastocyst morphological parameters, Grade B trophectoderm was significantly associated with a higher sex ratio than Grade C (aOR 1.71; 95% CI 1.33-2.21. P < 0.001). Neither expansion degree nor inner cell mass degree were significantly associated with the singleton sex ratio. CONCLUSIONS: A single high-quality blastocyst FET has a higher chance of resulting in a male infant than a female infant. The results demonstrate that grade B trophectoderm confers benefits in improving the implantation potential of male blastocysts.

HCG administration after endogenous LH rise negatively influences pregnancy rate in modified natural cycle for frozen-thawed euploid blastocyst transfer: a pilot study.

PURPOSE: The aim of the present study was to evaluate whether in a modified natural cycle (modified-NC) for a frozen-thawed single euploid blastocyst transfer, a critical LH value, above which human chorionic gonadotropin (hCG) administration should be avoided, may be defined. METHODS: One hundred and sixty-seven patients underwent modified natural cycle in order to transfer a single frozen-thawed euploid blastocyst. All embryos were obtained by intracytoplasmic sperm injection and were biopsied at the blastocyst stage and analyzed by means of array comparative genomic hybridization (aCGH). Ovulation was induced using 10.000 IU hCG when the mean follicle diameter was at least of 17 mm, independently from LH values. The primary end points were the hCG-positive test and clinical pregnancy. The interim analysis showed that LH value ≥ 13 mIU/ml on the day of hCG injection may negatively influence the clinical results, suggesting that in this condition, it should be advisable waiting for spontaneous ovulation. RESULTS: Among patients who received hCG for ovulation induction, the hCG-positive test and clinical pregnancy rates in modified-NC were significantly lower in cycles with LH ≥ 13 mIU/ml in respect to those with LH < 13 mIU/ml (45.4 vs 73.3 and 36.4 vs 65.9%, in LH ≥ 13 and LH < 13 groups, respectively). In patients with LH value ≥ 13 mIU/ml, hCG administration led to significantly lower rates of hCG-positive test (45.4 vs 74.5% in hCG administration and spontaneous ovulation groups, respectively) and clinical pregnancy (36.4 vs 64.7% in hCG administration and spontaneous ovulation groups, respectively). The baseline patient characteristics were comparable in all groups. CONCLUSIONS: The findings of this study highlight that LH elevation ≥ 13 mIU/ml prior to hCG administration may negatively affect clinical pregnancy rates in modified-NC for single euploid blastocyst transfer. The LH determination should be routinely performed during follicular monitoring. In the presence of LH level ≥ 13 mIU/ml, hCG administration should be avoided, and the embryo transfer should be planned only after spontaneous follicular rupture.

Preferred strategy for euploid single embryo transfer in advanced maternal age: Fresh versus frozen.

OBJECTIVE: The purpose of this study was to compare fresh and frozen-thawed euploid blastocyst transfer protocols following preimplantation genetic screening (PGS) in cases of advanced maternal age. METHODS: A total of 330 patients were examined retrospectively. PGS was performed on the embryos of 146 patients for whom fresh transfers were chosen. In contrast, frozen-thawed euploid single embryo transfer (ET) was selected after PGS for 184 patients, and their embryos were vitrified. The percentage of euploid embryos and rates of implantation, pregnancy, and pregnancy continuity, as well as clinical and biochemical abortion rates, were compared. RESULTS: The numbers of retrieved oocytes, metaphase II oocytes, and fertilized ova were greater in the frozen-thawed group. The percentages of euploid embryos were comparable between the fresh and frozen-thawed groups (32% vs. 34.8%, respectively). The rates of implantation (46.6%vs. 62.5%), pregnancy (50% vs. 66.8%), ongoing pregnancy (38.4% vs. 53.8%), and live birth percentage (37.0% vs. 53.8%) were significantly higher in the frozen-thawed group. However, no significant differences were found in the clinical and biochemical abortion rates. CONCLUSION: The use of frozen-thawed single euploid ET is associated with increased implantation and pregnancy rates compared to fresh single euploid ET with PGS.

Use of hCG for luteal support in natural frozen-thawed blastocyst transfer cycles: a cohort study.

Introduction: In the realm of natural frozen-thawed embryo transfer (FET) cycles, the application of luteal phase support (LPS) is a prevalent practice, primarily due to its beneficial impact on reproductive outcomes. Among the various LPS medications, human chorionic gonadotropin (hCG) is one that exerts its function on both the corpus luteum and the endometrium. Objective: To evaluate the effect of hCG administration as LPS on reproductive outcomes in natural FET cycles. Methods: This study was a retrospective cohort analysis conducted at a tertiary care hospital. It included women who underwent natural FET treatment from January 2018 to December 2022. Participants were divided into the hCG LPS group and the non-hCG LPS group on the basis of whether they used hCG as LPS after blastocyst transfer. The primary outcome was the clinical pregnancy and live birth rates. The secondary outcomes included the early miscarriage rate (before 12th gestational week) and total miscarriage rate. Results: A total of 4762 women were included in the analysis, and 1910 received hCG LPS and 2852 received no hCG LPS (control group). In the general cohort, the clinical pregnancy and live birth rates in the hCG LPS group were significantly lower than those in the control group (63.82% vs 66.41%, aOR 0.872, 95% CI 0.765-0.996, P=0.046; 53.98% vs 57.15%, aOR 0.873, 95% CI 0.766-0.991, P=0.035, respectively). The early miscarriage and total miscarriage rates were similar between the two groups. In a subgroup analysis, in women who received an hCG trigger, there was no significant difference in the clinical pregnancy rate or live birth rate between the two groups. However, in women who ovulated spontaneously, the clinical pregnancy and live birth rates in the hCG LPS group were significantly lower than those in the control group (60.99% vs 67.21%, aOR 0.786, 95% CI 0.652-0.946, P=0.011; 50.56% vs 57.63%, aOR 0.743, 95% CI 0.619-0.878, P=0.001, respectively). Conclusion: Among women undergoing natural cycle frozen-thawed blastocyst transfer, hCG LPS is associated with lower clinical pregnancy and live birth rates. Additionally, the adverse effect of hCG LPS is more pronounced in women who ovulate spontaneously.

Influence of delayed blastulation and expansion grade on clinical outcomes of high-quality blastocyst transfer: an analysis of 1751 frozen-thawed cycles.

The aim of the study was to compare retrospectively the extent of blastulation timing (Day 5 or later) and expansion grade to predict the ability of blastocysts to give rise to a pregnancy. Blastocysts frozen on day 5 with a lower expansion grade (group D5) or day 6 with a higher expansion grade (group D6) were included. A single embryo was thawed and transferred on day 5 after ovulation or progesterone supplementation. Differences in patient baseline characteristics, endometrial preparation and pregnancy outcomes between groups were stratified by patient age and anti-Müllerian hormone (AMH) levels. Logistic regression was used to analyse the results. A total of 617 blastocysts in group D5 and 1134 blastocysts in group D6 were assessed. Stratified analyses showed higher biochemical pregnancy, clinical pregnancy and live birth rates for patients aged less than 30 years old, and higher ongoing pregnancy rate for patients with AMH ≥ 1.1 ng/ml. For patients aged less than 30 years old, the biochemical pregnancy, clinical pregnancy and live birth rates in group D5 were higher than those in group D6.

Association Between Fresh Embryo Transfers and Frozen-Thawed Embryo Transfers Regarding Live Birth Rates Among Women Undergoing Long Gonadotropin-Releasing Hormone Antagonist Protocols.

Background: The availability and use of frozen-thawed embryos after controlled ovarian hyperstimulation for assisted reproduction have increased with improvements in vitrification techniques and the rise of gonadotropin-releasing hormone (GnRH) antagonist protocols. Although evidence has shown that frozen-thawed embryo transfers (FETs) result in higher live birth rates than fresh embryo transfers, it is uncertain whether this association exists in cycles employing the GnRH antagonist protocol. Objective: To test the hypothesis that FETs are more likely to result in a live birth than fresh embryo transfers in a GnRH antagonist protocol cycle and to investigate whether frozen blastocyst transfer increases live birth rates compared to fresh blastocyst transfer. Design: A retrospective historical cohort study was conducted using data collected from the Department of Reproductive Medicine of Liuzhou Maternity and Child Healthcare Hospital for 1,437 patients who underwent the GnRH antagonist protocol between 1 January 2015, and 31 December 2020. The primary outcome was the live birth rate, which was compared between fresh embryo transfer and FET, and the secondary outcomes were clinical pregnancy rate and miscarriage rate, which were compared between the two groups. Analyses were adjusted to account for the age of the patient, number of embryo transfers, day of embryo transfer, and type of infertility. Results: Fresh embryo transfers accounted for 1,026 (71.4%) of the 1,437 patients who underwent the GnRH antagonist protocol in our analysis, while FETs accounted for 411 (28.6%). Patients with fresh and frozen-thawed embryos had comparable median body mass index (body mass index; 22.3 [IQR, 24.6-20.0] vs. 22.0 [IQR, 24.5-19.9]). There was a significant difference in the median age of the fresh embryo transfer group (34.0 [IQR, 39.0-30.0]) and the Frozen-thawed embryo transfer group (32.0 [IQR, 37.0-29.0]). Blastocysts were transferred in 14.6% of the fresh embryo transfer cycles and 45.5% of the FET cycles, whereas they account for 10.4% and 13.0% of all patients, respectively. The mean number of embryos transferred was 2 (IQR, 2.0-1.0) for the fresh embryo transfer group and 1 (IQR, 2.0-1.0) for the FET group, with a significant difference in the mean number of embryos transferred. The live birth rate after fresh embryo transfer vs. FET was 28.7% vs. 34.5% (absolute difference, 5.9%; adjusted relative risk [aRR], 1.15 [95% CI, 0.88-1.51]). The clinical pregnancy rates were 39.9% vs. 46.0%, respectively (absolute difference, 6.1%; aRR, 1.10 [95% CI, 0.85-1.43]). The miscarriage rates were 22.5% vs. 23.8%, respectively (absolute difference, 1.3%; aRR, 1.13 [95% CI, 0.75-1.70]). Conclusion: In this retrospective study of women who underwent assisted reproduction using GnRH antagonists, FETs resulted in a higher live birth rates and clinical pregnancy rates than fresh embryo transfers, which parts of these differences were attributable to embryo stage. However, the interpretation of the findings is limited by the possibility of selection and confounding biases.