We concluded that SCH was associated with lower birth weight in singleton pregnancy, but SCH did not increase pregnancy loss rate in IVF/ICSI patients, and fresh embryo transfer may contribute to SCH onset.

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BackgroundWhat role should previous cesarean section play in affecting clinical pregnancy outcomes and avoiding the complications of in vitro fertilization? In this article, we focus on elective single-embryo transfer (eSET) versus double-embryo transfer (DET) and assess the clinical efficacy and safety of eSET in patients who have a previous cesarean scar.Material/MethodsThe pregnancy, delivery, and neonatal outcomes of 130 patients who had a previous cesarean scar and received in vitro fertilization-embryo transfer (IVF-ET) were retrospectively analyzed. The number of transferred embryos was chosen depending on patients’ desire after acknowledging all benefits and risks, including eSET (eSET group, n=56) and DET (DET group, n=74). A total of 101 patients with previous vaginal delivery receiving IVF-ET in the same period were included as a control group.ResultsThe pregnancy rates, multiple birth rates, abortion rates, ectopic pregnancy rates, gestational age at delivery, preterm birth rates, neonatal birth weight, and take-home baby rates were similar between the previous cesarean section group and the previous vaginal delivery group. A previous cesarean section scar did not affect embryo implantation and pregnancy outcomes in IVF. In the eSET and DET groups of previous cesarean section patients, the embryo implantation rates, pregnancy rates, abortion rates, and take-home baby rates were similar. However, the rate of multiple pregnancies reached 50% in the DET group, which led to more preterm births and lower birth weight.ConclusionsElective single-embryo transfer is a well-accepted strategy to avoid multiple pregnancies and improve the obstetric and neonatal outcomes of singleton pregnancy in IVF patients with a previous cesarean section.

Mitochondria play a critical role in cell function and embryo development. Recently, increasing studies have investigated whether mitochondrial DNA (mtDNA) can be used as a predictive biomarker of embryo implantation. However, the results of its effect on implantation are still controversial. To further understand the clinical application value of mtDNA content for reproductive potential, we analyzed the influence of relative mtDNA quantity on embryo quality and transfer outcomes based on the results of second-generation sequencing of preimplantation genetic testing patients in our center. Biopsied trophectoderm (TE) from aneuploid blastocysts contained much larger amounts of mtDNA than those from euploid blastocysts ( p < 0.000). In an analysis of only euploid blastocysts (n = 769), female age had no effect on mtDNA content ( p = 0.216). TE cells biopsied on day 5 (n = 355) contained significantly higher amounts of mtDNA compared to those biopsied on day 6 (n = 388) or day 7 (n = 26) ( p < 0.000). Higher quality trophoblast was associated with lower mtDNA content ( p = 0.026), but quality of inner cell mass was not correlated with quantity of mtDNA ( p = 0.112). For transferred embryos, the biopsied date and mtDNA content were significantly associated with embryo implantation and live birth outcomes. Day-5 euploid blastocysts with lower quantities of mtDNA exhibited higher implantation rate and live birth rate. However, our data indicated that mtDNA content may not be considered an independent predictive marker, it may be a useful reference for the selection of day-5 transferred euploid blastocysts.