Assessing the relationship between neonatal abstinence syndrome and birth defects in Delaware

Neonatal abstinence syndrome (NAS) is a withdrawal syndrome in newborns and is frequently caused by maternal opioid use during pregnancy. Our study examines whether NAS is associated with birth defects in Delaware.

We conducted a retrospective analysis of linked Delaware birth certificate data (BCD), hospital discharge data (HDD), and birth defects registry (BDR) data to examine the association between NAS and birth defects for all hospital births to Delaware residents from 2010 to 2017. Birth defects data were abstracted from medical records from Delaware's BDR. We used International Classification of Diseases Ninth and Tenth Revision Clinical Modification (ICD-9-CM/ICD-10-CM) 779.5 and P96.1 codes to determine NAS using HDD and excluded iatrogenic cases of NAS. We estimated crude and adjusted odds ratio with 95% confidence intervals (CIs).

During 2010-2017, there were 2,784 cases of birth defects and 1,651 cases of NAS in Delaware. Among infants with a diagnosis of NAS, 56 also had a birth defect (3.4%), similar to 2,728 birth defects among 79,636 infants without a diagnosis of NAS (3.4%). We found no statistically significant association between an NAS diagnosis and birth defects (adjusted odds ratios = 1.0; 95% CI: 0.8-1.3).

Our multiyear state-wide study using linked BCD, HDD, and BDR data for Delaware did not show a statistically significant association between infants diagnosed with NAS and birth defects, overall.