Embryos derived from donor or patient oocytes are not different for in vitro fertilization outcomes when PGT allows euploid embryo selection: a retrospective study

Blastocyst Morphology Based on Uniform Time-Point Assessments is Correlated With Mosaic Levels in Embryos

Avoiding aneuploid embryo transfers has been shown to improve pregnancy outcomes in patients with implantation failure and pregnancy loss. This retrospective cohort study aims to analyze the correlation of time-lapse (TL)-based variables and numeric blastocyst morphological scores (TLBMSs) with different mosaic levels. In total, 918 biopsied blastocysts with time-lapse assessments at a uniform time-point were subjected to next-generation sequencing–based preimplantation genetic testing for aneuploidy. In consideration of patient- and cycle-related confounding factors, all redefined blastocyst morphology components of low-grade blastocysts, that is, expansion levels (odds ratio [OR] = 0.388, 95% confidence interval [CI] = 0.217–0.695; OR = 0.328, 95% CI = 0.181–0.596; OR = 0.343, 95% CI = 0.179–0.657), inner cell mass grades (OR = 0.563, 95% CI = 0.333–0.962; OR = 0.35, 95% CI = 0.211–0.58; OR = 0.497, 95% CI = 0.274–0.9), and trophectoderm grades (OR = 0.29, 95% CI = 0.178–0.473; OR = 0.242, 95% CI = 0.143–0.411; OR = 0.3, 95% CI = 0.162–0.554), were less correlated with mosaic levels ≤20%, <50%, and ≤80% as compared with those of top-grade blastocysts (p < 0.05). After converting blastocyst morphology grades into scores, high TLBMSs were associated with greater probabilities of mosaic levels ≤20% (OR = 1.326, 95% CI = 1.187–1.481), <50% (OR = 1.425, 95% CI = 1.262–1.608), and ≤80% (OR = 1.351, 95% CI = 1.186–1.539) (p < 0.001). The prediction abilities of TLBMSs were similar for mosaic levels ≤20% (AUC = 0.604, 95% CI = 0.565–0.642), <50% (AUC = 0.634, 95% CI = 0.598–0.671), and ≤80% (AUC = 0.617, 95% CI = 0.576–0.658). In conclusion, detailed evaluation with TL monitoring at the specific time window reveals that redefined blastocyst morphology components and converted numeric TLBMSs are significantly correlated with all of the threshold levels of mosaicism. However, the performance of TLBMSs to differentiate blastocysts with aberrant ploidy risk remains perfectible.

The association between prior cesarean delivery and subsequent in vitro fertilization outcomes in women undergoing autologous, frozen-thawed single euploid embryo transfer

BACKGROUND

The rates of cesarean deliveries continue to increase worldwide. Previous work suggests an association between a previous cesarean delivery and reduced fertility in natural conception and in vitro fertilization treatment cycles. To our knowledge, there is no published research that explored the relationship between a previous cesarean delivery and the clinical outcomes after in vitro fertilization and the subsequent transfer of a single frozen-thawed euploid embryo.

OBJECTIVE

This study aimed to investigate the relationship between the previous mode of delivery and subsequent pregnancy outcomes in patients undergoing a single frozen-thawed euploid embryo transfer after in vitro fertilization.

STUDY DESIGN

A retrospective cohort study was performed at a single academic fertility center from January 2012 to April 2020. All women with a history of a live birth undergoing autologous, frozen-thawed single euploid embryo transfers were identified. Cases included patients with a single previous cesarean delivery; controls included patients with a single previous vaginal delivery. Only the first embryo transfer cycle was included. The primary outcome was the implantation rate. Secondary outcomes included ongoing pregnancy and live birth rates, biochemical pregnancy rate, and clinical miscarriage rate.

RESULTS

A total of 525 patients met the inclusion criteria and were included in the analysis. Patients with a previous cesarean delivery had a higher body mass index (24.5±4.5 vs 23.4±4.1; P=.004) than those in the vaginal delivery cohort; the rest of the demographic data were otherwise similar. In a univariate analysis, the implantation rate was significantly lower in patients with a previous cesarean delivery (111/200 [55.5%] vs 221/325 [68.0%]; P=.004). After adjusting for the relevant covariates, a previous cesarean delivery was associated with a 48% reduction in the odds of implantation (adjusted odds ratio, 0.52; 95% confidence interval, 0.34-0.78; P=.002). In addition, after adjusting for the same covariates, a previous cesarean delivery was significantly associated with a 39% reduction in the odds of an ongoing pregnancy and live birth (adjusted odds ratio, 0.61; 95% confidence interval, 0.41-0.90; P=.01). There were no differences in the biochemical pregnancy rates or clinical miscarriage rates.

CONCLUSION

This study demonstrated a marked reduction in implantation and ongoing pregnancy and live birth associated with a previous cesarean delivery in patients undergoing a single euploid embryo transfer. Our work stresses the importance of reducing the primary cesarean delivery rates at a national level and elucidating the mechanisms behind the substantially lower implantation rates after a cesarean delivery.