Evidence for assisted reproductive technology associated epigenetic variation in humans

Assisted Reproductive Technologies (ARTs) have resulted in more than 8 million births since 1978. Compared with spontaneously conceived babies, ART-conceived babies are at an increased risk of preterm birth, low birth weight, being small or large for gestational age, congenital anomalies, and perinatal mortality. Early studies showed that ART conception was associated with a higher incidence of rare imprinted disorders, stimulating interest in assessing epigenetic variation associated with ART and linking this variation to poor perinatal outcomes. In this chapter, we summarize the current state of the epigenetic and ART field in humans. We focus on epigenome-wide association studies of human blood at birth and address the temporal, cell-type–specific, and ART-component–specific findings. In recent years, studies have begun to replicate specific DNA methylation changes associated with ART. The next phase of research will be to explain how these epigenetic differences arise and whether they mediate the adverse perinatal outcomes observed in ART pregnancies.