Epigenetic variation in neonatal tissues in infants conceived using capacitation-in vitro maturation vs. in vitro fertilization

Abstract

ObjectiveTo investigate alterations of the global DNA methylation profile in placenta, cord blood and neonatal buccal smears in infants conceived using in vitro maturation (IVM) with a prematuration step (capacitation-IVM [CAPA-IVM] versus in vitro fertilization (IVF). DesignAnalysis of data from the offspring of participants in a randomized controlled trial. SettingPrivate clinic. PatientsForty-six women with polycystic ovary syndrome and/or high antral follicle count and their offspring (58 newborns). Intervention(s)Women with polycystic ovary syndrome and/or a high antral follicle count participating in the clinical trial were randomized to undergo CAPA-IVM or conventional IVF. Main Outcome Measure(s)At delivery, biological samples including cord blood, placental tissue, and neonatal buccal smear were collected. Genome-wide DNA methylation was determined by Illumina Infinium MethylationEPIC BeadChip. Variability in methylation was also considered and mean variances for the two treatment categories were compared. ResultsIn neonatal buccal smears, there were no significant differences between the CAPA-IVM and conventional IVF groups based on CpG probe after linear regression analysis using a significant cut-off of false discovery rate <0.05 and |Δβ|≥0.05. In cord blood, only one CpG site showed a significant gain of methylation in the CAPA-IVM group. In placenta, CAPA-IVM was significantly associated with changes in methylation at five CpG sites. Significantly more variable DNA methylation was found in five probes in placenta, 54 in cord blood and two in buccal smears after IVM of oocytes. In cord blood samples, 20 CpG sites had more variable methylation in the conventional IVF versus IVM group. Isolated CpG sites showing differences in methylation in cord blood were not associated with changes in gene expression of the overlapping genes. Conclusion(s)CAPA-IVM appeared to be associated with only a small amount of epigenetic variation in cord blood, placental tissue and neonate buccal smears.