Impact of the one-carbon metabolism on oocyte maturation, fertilization, embryo quality, and subsequent pregnancy.

PURPOSE: To investigate impact of the one-carbon metabolism (OCM) on oocyte maturity and embryo development. METHODS: This prospective study analyzed 18 women who agreed to participate. We measured the OCM biomarkers' concentrations including Vitamin B12 (VB12), folic acid (FA), and homocysteine (Hcy) in serum and follicular fluid (FF), and assessed their correlation. We also evaluated the influence of such OCM biomarker concentrations in mono-FF on oocyte maturation, fertilization, embryo quality, and consequent pregnancy after embryo transfers. RESULTS: All biomarkers showed a high concentration variability in different follicles of each woman, but their mean levels correlated with the serum levels. Among the 106 collected oocytes, 92 were mature, 59 were fertilized, and 16 yielded good-quality embryos. We performed 26 single embryo transfers, and 7 patients achieved clinical pregnancies. VB12 concentration (FF) was significantly lower in fertilized than unfertilized oocytes by univariate analysis. In multivariate logistic analysis, a significant correlation was found between FA concentration (FF) <14.25 ng/mL and good-quality embryos and between Hcy concentration (FF) <4.9 nmol/mL and clinical pregnancy. CONCLUSION: OCM in FF may affect fertilization, embryo quality, and clinical pregnancy.

Comparative study of obstetric and neonatal outcomes of live births between poor- and good-quality embryo transfers.

PURPOSE: To evaluate the effect of embryo quality on pregnancy outcomes. METHODS: This retrospective analysis included 80 live singleton births, resulting from morphologically good-quality embryo transfers, and 25 live singleton births that resulted from morphologically poor-quality embryo transfers between January, 2008 and December, 2014. Cleavage embryos that were graded as ≥2, according to the Veeck classification system, and blastocysts that were graded as ≥3BB, according to the Gardner classification system, were defined as good quality. The obstetric and neonatal outcomes were compared between the poor- and good-quality embryo transfer groups. RESULTS: The mean maternal age between the groups was similar. The blastocyst transfer rate was higher in the good-quality, than in the poor-quality, embryo transfer group. Other characteristics, including parity, infertility duration, the intracytoplasmic sperm injection rate, frozen-thawed embryo transfer rate, endometrial thickness, and hormone values before the embryo transfer, were similar between the groups. The obstetric and neonatal outcomes of live births between the two groups were not different in terms of preterm delivery, birthweight, small or large size for gestational age, malformation, umbilical artery cord pH of <7.20, hypertensive disorders of pregnancy, gestational diabetes mellitus, chorioamnionitis, placenta previa, and placental abruption. CONCLUSION: The obstetric and neonatal outcomes of live births between the poor- and good-quality embryo transfers were equivalent.

Sex ratio of infants born through in vitro fertilization and embryo transfer: Results of a single-institution study and literature review.

OBJECTIVE: The possible effects of Assisted Reproductive Technology (ART) on sex ratio at birth are extremely significant. This study aimed to determine whether ART affects the sex ratio of infants born through in vitro fertilization and embryo transfer (IVF-ET). MATERIALS AND METHODS: We ran this retrospective study on 290 singleton infants born following IVF-ET from February 2014 to August 2018 at a single institution. We compared the sex ratios of these infants with respect to insemination versus intracytoplasmic sperm injection (ICSI), early-cleavage embryo versus blastocyst transfer, fresh versus frozen-thawed embryo transfer and normal sperm versus asthenospermia. RESULTS: There were no significant differences in the sex ratio with respect to the fertilization method, transfer time, fresh embryo or frozen-thawed embryo transfer. In addition, the multiple logistic regression analysis revealed that these factors did not significantly affect the sex ratio. CONCLUSIONS: Our study indicated that the differences in the fertilization method transfer time and sperm motility rate did not affect the sex ratio of IVF live births. However, with increasing numbers of ICSI and blastocyst transfer cycles, factors possibly affecting the sex ratio need to be further investigated.