Evaluation of DNA methylation status at differentially methylated regions in IVF-conceived newborn twins.

Objective: To examine the effect of assisted reproductive technology on the stability of DNA methylation at differentially methylated regions (DMRs) in twins conceived by IVF.

Methods: Prospective clinical observational study. Methods: IVF center, university-affiliated teaching hospital. Methods: Fifty-nine pairs of twins were recruited, including 29 pairs conceived through IVF and 30 pairs of naturally conceived twins. Methods: Collection of umbilical cord blood samples. Methods: DNA was extracted from umbilical cord blood. Two maternally methylated regions (KvDMR1 and PEG1) and one paternally methylated region (H19/IGF2 DMR) were analyzed using bisulfite-based technologies.

Results: Although H19/IGF2 DMR and KvDMR1 showed slightly more variable levels of methylation in IVF cases than in spontaneous cases, methylation indices did not reveal significant differences at three DMRs between IVF-conceived and naturally conceived twins.

Conclusions: Our results suggest no significant increase in imprint variability at these DMRs, but the greater variance in the IVF twins has a biologically meaningful consequence and may be a topic for future investigation. Large cohorts are needed to systematically assess the potential epigenetic risk in twins conceived with IVF.