Objective: Evaluate maternal and neonatal outcomes after buprenorphine wean compared to patients maintained on buprenorphine throughout pregnancy.
Methods: Prospective cohort study of pregnant patients with opioid use disorder enrolled in a multidisciplinary treatment program between 2015 and 2022. All patients were offered Medications to treat Opioid Use Disorder (MOUD) primarily with buprenorphine. Patients had at least 2 prenatal visits and negative urine drug tests (UDT) prior to weaning. The experimental group underwent a buprenorphine wean greater than 20% of their baseline dose. The control group was maintained on buprenorphine throughout the pregnancy. Relapse was defined as patient reported use or positive UDT during weekly assessments. Mass spectrophotometer was used for detection of drugs in samples. Fisher's exact tests were used to compare outcomes in weaned and control groups.
Results: 334 of 456 (73%) patients were treated with buprenorphine during pregnancy, with 39 in the experimental group and 295 in the control group. The mean dose for buprenorphine was similar between the groups (wean: 10.6 mg ± 5.6 vs. control: 10.3 mg ± 4.6, p = 0.76) but was significantly lower at delivery (wean: 4.4 ± 4.6 mg vs. control: 13.0 ± 4.7, p < 0.0001). Mean gestational age at initiation of the buprenorphine wean was 22.7 weeks. 10 of 39 (26%) who weaned were able to completely discontinue buprenorphine prior to delivery. Demographic data was similar between the groups, including overdose history. Overdose history at time of enrollment had a higher trend in the non-weaning group. neonatal opioid withdrawal syndrome (NOWS) treatment was significantly lower in the wean group (23 vs. 47%, p = 0.006), as was highest Finnegan score (9.6 ± 4.5 vs. 12.3 ± 4.0, p = 0.0003). Birthweight percentile was significantly higher in the wean group (44.3 ± 29.9 vs. 34.8 ± 24.4, p = 0.03). Gestational age at delivery, mode of delivery, and complications (HTN, DM, preterm labor, or short cervix) at delivery did not significantly differ between the groups.
Conclusion: Despite counseling to stay on buprenorphine, there are patients who desire to wean. The NOWS rate in the weaned cohort was significantly lower than the controls with no observed increase in maternal or neonatal morbidity. There were no maternal overdoses or deaths during the pregnancy. Larger studies are needed to evaluate this approach.
Keywords: Buprenorphine wean; MAT; MOUD; opioid use disorder; pregnancy.