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Assisted reproductive technology associated with certain birth defects

Recent findings published in JAMA Pediatrics indicated that infants conceived with assisted reproductive technology had a greater prevalence of nonchromosomal birth defects.

“Our study found that infants conceived by in vitro fertilization (IVF) were at an increased risk for certain birth defects,” Sheree L. Boulet, DrPH, MPH, at the CDC’s National Center for Chronic Disease Prevention and Health Promotion, told Healio Internal Medicine. “However, our manuscript suggests that factors related to underlying subfertility — which is what leads many couples to explore [assisted reproductive technology (ART)] services — could increase the risk of birth defects.”

In 2012, about 1.5% of liveborn infants in the United States were conceived using ART, defined as fertility treatments where eggs or embryos are handled outside the body. Meta-analyses mainly conducted in non-U.S. populations have found that children conceived with ART have an increased risk for nonchromosomal birth defects compared with spontaneously conceived infants. Because ART and birth defects occur infrequently, however, the researchers aimed to study a U.S. population cohort large enough to determine the risk.

Sheree L. Boulet

The researchers used linked ART surveillance, birth certificates and birth defects registry data for Florida, Massachusetts and Michigan that spanned 2000 to 2010 and included 4,618,076 resident live births. Of these births, 1.4% were conceived using ART. Overall, they found at least one nonchromosomal birth defect occurred in 59.97 infants per 10,000 live births with ART (n = 389) vs. 48.4 per 10,000 infants conceived without ART (n = 22,036).

After factoring in maternal characteristics and year of birth, the researchers found the association to remain significant (adjusted RR = 1.28; 95% CI, 1.15-1.42). For singleton children, they observed birth defects in 64.88 per 10,000 infants born with ART (n = 218) and in 48.07 per 10,000 infants conceived without ART (n = 21,251). After the same adjustments, they found an even more significant association (aRR = 1.39; 95% CI, 1.21-1.59). Among multiple births, the prevalence of rectal and large intestinal atresia/stenosis was higher for infants born with ART than in infants conceived without ART (aRR = 2.39; 95% CI, 1.38-4.12).

Among ART births conceived after a fresh embryo transfer, infants born to mothers with ovulation disorders showed a marginally greater prevalence of nonchromosomal birth defects than those born to mothers without the disorders (aRR = 1.53; 95% CI, 1.13-2.06). In addition, the use of assisted hatching was associated with birth defects among singleton births (aRR = 1.55; 95% CI, 1.1-2.19). No single procedure, however, was found to substantially increase the risk for birth defects among ART births, Boulet and colleagues wrote.

“As more and more infants are conceived through ART, it continues to be important to understand the long-term health impacts of the procedures and the potential effects of infertility,” Boulet said. “ART remains a safe and effective treatment for infertility, but these findings can add to the conversation providers and patients have when discussing ART risks.” – by Will Offit

Disclosure: The researchers report no relevant financial disclosures.