Objectives: In this study, buprenorphine was the primary source of maternal opioid exposure at the time of initial prenatal evaluation. Current recommendations advise that level II ultrasounds be performed in patients with substance use disorders. For some patients, distance, transportation, and costs associated with obtaining ultrasounds from a specialist pose significant barriers. This study was thus undertaken to evaluate the value of level II ultrasounds in buprenorphine-exposed pregnancies.
Methods: In a retrospective chart review comparing 1188 substance-exposed patients with 1261 nonexposed, anomaly data were collected from level I and level II anatomy scans, problem lists on prenatal flowsheets, and visit notes. If anomalies were detected, then they were further classified by the affected organ system. Two proportion tests were used to compare the exposed and unexposed groups. When the assumptions were not met, a Fisher exact test and the Benjamini-Hochberg method were used to adjust for multiple testing.
Results: Buprenorphine-exposed fetuses have increased rates of composite skeletal anomalies when compared with nonexposed fetuses (P< 0.005). No statistically significant difference, however, was found between groups for any other system or for any specific skeletal anomaly. No statistical difference was found related to buprenorphine dose.
Conclusions: This is the first report of skeletal anomalies in buprenorphine-exposed human fetuses. Causality is unproven, but this report is consistent with prior human and animal studies in which maternal opioid use has been linked to significant impairments in bone growth and development. Our findings suggest that anatomic surveys of fetuses exposed to buprenorphine should be performed by individuals with expertise in the detection of fetal skeletal anomalies.