Decreased Sonographic Head Circumference Is Found in Buprenorphine-Exposed Fetuses ID 2683396

INTRODUCTION: Neonates diagnosed with neonatal opioid withdrawal syndrome (NOWS) have decreased head circumference compared to non-exposed newborns. This is the first study to evaluate fetal head circumference over time in a group of fetuses with intrauterine buprenorphine exposure. METHODS: Fetal anatomic surveys are commonly performed at around 20 weeks of gestation. Patients treated with medication-assisted therapy (MAT) for opioid use disorder commonly receive estimated fetal weight scans at around 32 weeks of gestation due to the risk of intrauterine growth restriction. Retrospective review of ultrasound reports for three groups of patients were performed. Group 1 (75 patients) was low-dose MAT; group 2 (73 patients) was traditional higher-dose MAT. Group 3 (104 patients) was a control group. The IRB approval was 1220.9e-ETSU, entitled “Effect of Maternal Buprenorphine on Fetal Head Circumference.” RESULTS: At the time of the approximately 20-week scan, no statistical difference was found between the groups. At the approximately 32-week growth scan, however, a comparison of the two buprenorphine groups together versus control group showed a statistically significant difference ( P =.018) in head circumference. Although the low-dose group had larger head circumferences than the higher-dose group in the 32-week scan, the difference was not significant. CONCLUSION: Previous studies have shown decreased head circumference in newborns in association with maternal MAT. This is the first study to provide ultrasound confirmation of decreased head circumference in fetuses exposed to buprenorphine. Effects are pronounced in the third trimester; the possibility exists that interventions during pregnancy might preserve fetal brain volume. Further research is needed.