Impact of Type of Opioid Use on Methadone Dose at Delivery in Pregnant Women [13L

Abstract

INTRODUCTION: In our institution, the methadone initiation protocol for treatment of opioid use disorder (OUD) in pregnancy does not differentiate between heroin use and use of prescribed or diverted prescription opioids. We sought to determine whether there is a difference in methadone dose at delivery when comparing these two groups. METHODS: This is a retrospective cohort study of pregnant women with OUD treated with methadone at our institution from 2012-2017. The primary outcome was methadone dose at delivery. We compared women with prior heroin use to women with prior prescribed or diverted prescription opioid use alone. RESULTS: There were 335 patients identified. Of these, 254 reported heroin use, and 81 reported prescription opioid use alone. There were differences in baseline characteristics. A higher proportion of patients with prior heroin use were white (87 vs. 63%, p<.0001). A lower proportion were multiparous. Patients with prior heroin use had a lower mean initial BMI (25.70 vs. 27.15, p=.039). Prior to adjustment, there was a significant difference in methadone dose at delivery between the two groups (144.4 mg vs. 123.2 mg, p=0.013). After adjustment for covariates, this was no longer significant. In the adjusted model, only race was significant, with non-white women receiving significantly lower doses (107.59 mg vs. 145.75 mg, p<0.001). CONCLUSION: After adjusting for race, parity and initial BMI, there is no significant difference in methadone dose at delivery between women with prior heroin use vs. prescription opioid use. Women of non-white race have significantly lower methadone dose at delivery compared to white women.