Neonatal opioid withdrawal and antenatal opioid prescribing.

Abstract

The incidence of neonatal opioid withdrawal is increasing in both Canada and the United States. However, the degree to which the treatment of pain with opioids, rather than the misuse of prescription opioids or heroin, contributes to the prevalence of neonatal opioid withdrawal remains unknown. We conducted a retrospective, population-based, cross-sectional study between 1992 and 2011 in Ontario with 2objectives. First, we determined the annual incidence of neonatal abstinence syndrome. Second, using data from a subset of women eligible for publicly funded prescription drugs, we determined what proportion of women who deliver an infant with neonatal abstinence syndrome were given a prescription for an opioid before and during pregnancy. The incidence of neonatal abstinence syndrome in Ontario increased 15-fold during the study period, from 0.28 per 1000live births in 1992 to 4.29 per 1000live births in 2011. During the final 5years of the study, we identified 927deliveries of infants with neonatal abstinence syndrome to mothers who were public drug plan beneficiaries. Of these mothers, 67% had received an opioid prescription in the 100days preceding delivery, including 53.3% who received methadone, an increase from 28.6% in the interval spanning 1 to 2years before delivery (p<0.001). Prescription for nonmethadone opioids decreased from 38% to 17% (p<0.001). The incidence of neonatal opioid withdrawal in Ontario has increased substantially over the last 20years. Most of the women in this cohort who delivered an infant with neonatal abstinence syndrome had received a prescription for an opioid both before and during their pregnancy.