(603) Differences in dosing strategies and perinatal outcomes for pregnant persons on buprenorphine compared with buprenorphine-naloxone

There is insufficient data on buprenorphine-naloxone (BUP-NA) in pregnancy, furthermore there is limited data to guide dosing strategies for medications for opioid use disorder (MOUD) beyond withdrawal symptoms. This study sought to compare perinatal outcomes between buprenorphine (BUP) and BUP-NA along with evaluating dosing alterations in pregnancy.

Study Design:

Retrospective single institution cohort study of pregnant persons with OUD who delivered between 2017 and 2023. Patients were divided based on MOUD: BUP vs BUP-NA. Exclusion criteria were no MOUD or methadone use for MOUD. Patient characteristics, obstetric and neonatal outcomes were collected, along with dosing requirements at the start of MOUD in pregnancy and at delivery. Groups were compared groups using Chi-square, McNemar test, and t-tests with statistical significance defined as p < 0.05.

Results:

255 patients were identified. No differences were found comparing perinatal outcomes except for active drug use during pregnancy (p=0.04) (Table 1). Obesity (p=0.25), AMA (p=0.59), government assisted insurance (p=0.13), race/ethnicity (p=0.82), and rate of neonatal opioid withdrawal syndrome (NOWS) (p=.97) were similar. Changes in MOUD dosing occurred in 50.6% of patients. Initially, 50.5% of patients were on a split dosing strategy, and the rate increased by 17.5% by delivery, with 68% of patients requiring split dosing (p< 0.01). There was no difference in dosing frequencies between groups in the beginning of pregnancy versus delivery. More patients taking BUP-NA (69%) required an increase in dosage during pregnancy vs BUP (46.1%, p < 0.01). The frequency of weaning between the two groups (p=0.523) was similar with the majority (73.5%) not weaning.

Conclusion:

Perinatal outcomes including NOWS were similar between BUP and BUP-NA in our cohort, supporting the growing literature of safety of BUP-NA in pregnancy. Split dosing strategies were required more frequently throughout pregnancy for all patients, however patients taking BUP-NA may need increased dosages during pregnancy compared to patients taking BUP.