Assisted Reproductive Technology and Epigenetics.

Assisted reproductive technology (ART) is responsible for 1.7% of births in the United States annually. Despite a large number of studies promoting the efficacy and safety of these practices, there have been reports of imprinting disorders occurring at higher frequencies in children born through ART. Driven by findings in animal studies, it has been postulated that various ART procedures employed at critical points in embryonic development may predispose the genomic imprinting process to errors. Alterations in DNA methylation patterns at imprinting control centers have been reported by some studies to occur more frequently in children with imprinting disorders conceived by ART compared with spontaneous conception, though these findings are not consistently demonstrated and controversy has surrounded the strength of these associations. The rarity of imprinting disorders with a reliance of studies on disease registry cohorts, wide variations in ART protocols, and a lack of proper control groups limit the ability to substantiate associations between imprinting disorders and ART. Large, prospective cohort studies with a focus on molecular etiologies of these conditions are needed to discern whether a true association exists. Based on current evidence, the absolute risk of imprinting disorders after ART is low and screening for imprinting disorders in children conceived by ART is not warranted. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.