Reproductive technologies, female infertility, and the risk of imprinting-related disorders

Epidemiological studies suggest that singletons born from assisted reproductive technologies (ART) have a high risk of adverse perinatal outcomes, specifically for imprinting disorders. Because ART processes take place at times when epigenetic reprogramming/imprinting are occurring, there is concern that ART can affect genomic imprints. However, little is currently known about the risk of imprinting defects according to the type of ART or the type of underlying female infertility. From the French national health database, a cohort of 3,501,495 singletons born over a 5-year period (2013-2017) following fresh embryo or frozen embryo transfers (fresh-ET or FET from in vitro fertilization), intrauterine insemination, or natural conception was followed up to early childhood. Based on clinical features, several syndromes/diseases involving imprinted genes were monitored. The effects of ART conception and the underlying cause of female infertility were assessed.

Compared with infants conceived naturally, children born after fresh-ET had a higher prevalence of imprinting-related diseases, with an aOR of 1.43 [95% CI 1.13-1.81, p = 0.003]. Namely, we observed an increased risk of neonatal diabetes mellitus (1.96 aOR [95% CI 1.43-2.70], p < 0.001). There was an overall independent increase in risk of imprinting diseases for children with mothers diagnosed with endometriosis (1.38 aOR [95% CI 1.06-1.80], p = 0.02). Young and advanced maternal age, primiparity, obesity, smoking, and history of high blood pressure or diabetes were also associated with high global risk.

This prospective epidemiological study showed that the risk of clinically diagnosed imprinting-related diseases is increased in children conceived after fresh embryo transfers or from mothers with endometriosis. The increased perturbations in genomic imprinting could be caused by controlled ovarian hyperstimulation and potentially endometriosis through the impairment of endometrial receptivity and placentation, leading to epigenetic feto-placental changes. Further studies are now needed to improve understanding of the underlying molecular mechanisms (i.e. genetic or epigenetic causes).