Chronic antenatal opioid exposure linked to reduced head circumference at birth
Maternal chronic opioid use during pregnancy sufficient to cause neonatal abstinence syndrome (NAS) poses an increased likelihood of smaller head circumference at birth in infants, a study has found.
The prospective cohort study included 429 neonates treated for NAS delivered from well-dated pregnancies ≥34 weeks’ gestation and 429 matched infants not exposed to opioids. Compared with controls, newborns with NAS had more frequent coexposures to benzodiazepines, stimulants, marijuana, gabapentin, tobacco and selective serotonin reuptake inhibitors.
Mean head circumference was markedly smaller in the NAS vs control group (33.04 vs 33.99 cm; p<0.0001). In the NAS group, the mothers of 372 infants (87 percent) were on opioid medication-assisted treatment (MAT).
Head circumference was in the ≤10th percentile in 30.1 percent (129 of 429) of infants with NAS and in the ≤3rd percentile in 8.2 percent (35 of 429 neonates).
Multivariate stepwise logistic analysis revealed that only chronic opioid use during gestation resulting in a neonate requiring NAS treatment emerged as a significant risk factor for the observed smaller head circumference.
Specifically, the relative risk for a head circumference in the ≤10th percentile was 2.53, with an adjusted odds ratio (OR) of 3.19 (2.23–4.56; p<0.0001), whereas the relative risk for a head circumference in the ≤3rd percentile was 4.38, with an adjusted OR of 4.67 (2.14–10.20; p<0.0001).
More studies investigating non-NAS newborns exposed to maintenance MAT, illicit opioids, or lesser doses and/or durations of MAT because of partial or complete maternal detoxification are required to determine if the current recommended management of opioid use disorder in pregnancy should be revisited, according to researchers.