Developmental potential of non- and mono-pronuclear zygotes and associated clinical outcomes in IVF cycles.

Purpose: This study aims to evaluate the developmental potential of 0PN, 1PN, and 2PN zygotes in IVF cycles and compare their clinical outcomes. Methods: We conducted a retrospective cohort study involving IVF patients. Blastocyst formation rates were assessed with 0PN, 1PN, and 2PN zygotes. Subsequently, we collected clinical outcome data following the transfer of these zygotes. Results: The overall blastulation rate was similar between 0PN (29.6%) and 2PN (32.1%) zygotes, but 1PN zygotes exhibited a significantly lower blastulation rate (17.0%) compared to both 0PN and 2PN zygotes. Similarly, the overall rate of good-quality blastulation was comparable between 0PN (15.3%) and 2PN (17.5%) zygotes, while 1PN zygotes showed a significantly lower rate (7.0%) compared to both 0PN and 2PN. Clinical pregnancy, ectopic pregnancy, implantation, and live birth rates were similar among single blastocyst frozen embryo transfers (FET) of 0PN, 1PN, and 2PN. Additionally, no significant differences were observed between single- and double-blastocyst FET of 0PN and 2PN. Conclusions: Our findings suggest that 0PN and 2PN zygotes have comparable developmental potential, while 1PN embryos exhibit lower developmental potential. Blastocyst FET outcomes appear similar among 0PN, 1PN, and 2PN zygotes.

Embryo Transfer Strategies for Women with Recurrent Implantation Failure During the Frozen-thawed Embryo Transfer Cycles: Sequential Embryo Transfer or Double-blastocyst Transfer?

OBJECTIVE: Both sequential embryo transfer (SeET) and double-blastocyst transfer (DBT) can serve as embryo transfer strategies for women with recurrent implantation failure (RIF). This study aims to compare the effects of SeET and DBT on pregnancy outcomes. METHODS: Totally, 261 frozen-thawed embryo transfer cycles of 243 RIF women were included in this multicenter retrospective analysis. According to different embryo quality and transfer strategies, they were divided into four groups: group A, good-quality SeET (GQ-SeET, n=38 cycles); group B, poor-quality or mixed-quality SeET (PQ/MQ-SeET, n=31 cycles); group C, good-quality DBT (GQ-DBT, n=121 cycles); and group D, poor-quality or mixed-quality DBT (PQ/MQ-DBT, n=71 cycles). The main outcome, clinical pregnancy rate, was compared, and the generalized estimating equation (GEE) model was used to correct potential confounders that might impact pregnancy outcomes. RESULTS: GQ-DBT achieved a significantly higher clinical pregnancy rate (aOR 2.588, 95% CI 1.267-5.284, P=0.009) and live birth rate (aOR 3.082, 95% CI 1.482-6.412, P=0.003) than PQ/MQ-DBT. Similarly, the clinical pregnancy rate was significantly higher in GQ-SeET than in PQ/MQ-SeET (aOR 4.047, 95% CI 1.218-13.450, P=0.023). The pregnancy outcomes of GQ-SeET were not significantly different from those of GQ-DBT, and the same results were found between PQ/MQ-SeET and PQ/MQ-DBT. CONCLUSION: SeET relative to DBT did not seem to improve pregnancy outcomes for RIF patients if the embryo quality was comparable between the two groups. Better clinical pregnancy outcomes could be obtained by transferring good-quality embryos, no matter whether in SeET or DBT. Embryo quality plays a more important role in pregnancy outcomes for RIF patients.

Maternal and neonatal outcomes of dichorionic twin pregnancies achieved with assisted reproductive technology: meta-analysis of contemporary data.

PURPOSE: Assisted reproductive technology (ART) is commonly used to achieve pregnancy and often results in dichorionic diamniotic (DCDA) twin pregnancies. However, the potential risks of ART on maternal and neonatal outcomes in these pregnancies are not well understood. The objective is to compare the maternal and neonatal outcomes in DCDA twin pregnancies between those achieved through ART and those spontaneously conceived (SC). METHODS: We carried out a systematic comprehensive search of electronic databases; namely, PubMed, Embase, Scopus, and the Cochrane Library, from inception to March 2023 with a study period of recruitment between 2003 and 2023. We included all studies comparing the maternal and neonatal outcomes of DCDA twin pregnancies between those achieved by ART and those SC. RESULTS: We analyzed data from 18 cohort studies involving 10,485 women with DCDA twin pregnancies. The meta-analysis showed that ART-conceived pregnancies had a significantly higher risk of preeclampsia or gestational hypertension (GH), gestational diabetes mellitus (GDM), placenta previa (PP), placental abruption (PA), postpartum hemorrhage (PPH), and elective and emergency cesarean sections than SC twin pregnancies. The absolute risks of these complications remained relatively low. We also found a slightly higher risk of respiratory distress syndrome (RDS) and congenital malformations in ART-conceived infants compared to the risks in SC infants. Finally, the risk of neonatal intensive care unit (NICU) admissions was significantly higher in ART-conceived infants than in SC infants, but with high heterogeneity. CONCLUSION: We found associations between DCDA twin pregnancies conceived through ART and increased frequencies of adverse maternal outcomes. However, the absolute risks of these complications remained low, and the benefits of ART for achieving successful pregnancies may well outweigh the potential risks. Additionally, ART-conceived DCDA twin pregnancies may pose higher risks of RDS, congenital malformations and NICU, admissions than SC DCDA twin pregnancies.