Assisted reproductive technology alters deoxyribonucleic acid methylation profiles in bloodspots of newborn infants

Abstract

Objective: To evaluate the effect of infertility and intracytoplasmic sperm injection (ICSI) on DNA methylation of offspring.

Design: Microarray analysis of DNA methylation in archived neonatal bloodspots of in vitro fertilization (IVF)/ICSI-conceived children compared with controls born to fertile and infertile parents.

Setting: Academic research laboratory.

Patient(s): Neonatal blood spots of 137 newborns conceived spontaneously, through intrauterine insemination (IUI), or through ICSI using fresh or cryopreserved (frozen) embryo transfer.

Intervention(s): None.

Main outcome measure(s): The Illumina Infinium HumanMethylation450k BeadChip assay determined genome-wide DNA methylation. Methylation differences between conception groups were detected using a Bioconductor package, ChAMP, in conjunction with Adjacent Site Clustering (A-clustering).

Result(s): The methylation profiles of assisted reproductive technology and IUI newborns were dramatically different from those of naturally (in vivo) conceived newborns. Interestingly, the profiles of ICSI-frozen (FET) and IUI infants were strikingly similar, suggesting that cryopreservation may temper some of the epigenetic aberrations induced by IVF or ICSI. The DNA methylation changes associated with IVF/ICSI culture conditions and/or parental infertility were detected at metastable epialleles, suggesting a lasting impact on a child's epigenome.

Conclusion(s): Both infertility and ICSI alter DNA methylation at specific genomic loci, an effect that is mitigated to some extent by FET. The impact of assisted reproductive technology and/or fertility status on metastable epialleles in humans was uncovered. This study provides an expanded set of loci for future investigations on IVF populations.

Keywords: 450k; ART; ICSI; epialleles; epigenetics.