Prevalence of birth defects among infants with neonatal abstinence syndrome in Illinois, 2015-2016.

BACKGROUND: Opioid use has reached historically high levels across the United States and infants exposed during pregnancy are at risk of developing a drug withdrawal syndrome called neonatal abstinence syndrome (NAS). The prevalence of birth defects among Illinois infants exhibiting NAS has not been estimated.

METHODS: We linked birth certificate data for Illinois-resident infants born in Illinois in 2015 or 2016 to previously collected NAS and Adverse Pregnancy Outcome Reporting System birth defect data. We examined the prevalence of selected specific birth defects and of newborn infants with one or more of the National Birth Defects Prevention Network's (NBDPN) birth defects, comparing infants with and without NAS. We used logistic regression to estimate the odds ratio for having one or more NBDPN birth defects in infants with and without NAS, after adjusting for other risk factors.

RESULTS: Of 302,043 Illinois-resident births, 899 (3.0/1,000 live births) had NAS, and 4,250 (140.7/10,000 live births) had one or more NBDPN birth defect. Infants with an NBDPN birth defect were 1.9 (95% CI [1.3, 2.9]) times more likely to have developed NAS at delivery, and specifically, there was a higher prevalence of ventricular septal defect, club foot, and oral cleft, among infants with NAS when compared to those born without.

CONCLUSIONS: Elevated prevalence rates and odds ratios add to the growing evidence of an association between NAS and birth defects. Other studies have found similar associations between opioid exposure and the birth defects identified in this analysis.