Initiation and Treatment Discontinuation of Medications for Opioid Use Disorder in Pregnant People Compared With Nonpregnant People

OBJECTIVE: To examine the association between pregnancy and medications for opioid use disorder (MOUD) initiation and discontinuation among reproductive-aged people receiving treatment for opioid use disorder (OUD) in the United States. METHODS: We conducted a retrospective cohort study of people with gender recorded as female, aged 18-45 years, in the MerativeTM MarketScan (TM) Commercial and Multi-State Medicaid Databases (2006-2016). Opioid use disorder and pregnancy status were identified based on inpatient or outpatient claims for established International Classification of Diseases, Ninth and Tenth Revision diagnosis and procedure codes. The main outcomes were buprenorphine and methadone initiation and discontinuation, determined by using pharmacy and outpatient procedure claims. Analyses were conducted at the treatment episode level. Adjusting for insurance status, age, and co-occurring psychiatric and substance use disorders, we used logistic regression to estimate MOUD initiation and used Cox regression to estimate MOUD discontinuation. RESULTS: Our sample included 101,772 reproductive-aged people with OUD, encompassing 155,771 treatment episodes (mean age 30.8 years, 64.4% Medicaid insurance, 84.1% White), of whom 2,687 (3.2%, encompassing 3,325 episodes) were pregnant. In the pregnant group, 51.2% of treatment episodes (1,703/3,325) involved psychosocial treatment without MOUD, in comparison with 61.1% (93,156/152,446) in the nonpregnant comparator group. In adjusted analyses assessing likelihood of initiation for individual MOUD, pregnancy status was associated with an increase in buprenorphine (adjusted odds ratio [aOR] 1.57, 95% CI 1.44-1.70) and methadone initiation (aOR 2.04, 95% CI 1.82-2.27). Discontinuation rates of MOUD at 270 days were high for both buprenorphine (72.4% for nonpregnant episodes vs 59.9% for pregnant episodes) and methadone (65.7% for nonpregnant episodes vs 54.1% for pregnant episodes). Pregnancy was associated with a decreased likelihood of discontinuation at 270 days for both buprenorphine (adjusted hazard ratio [aHR] 0.71, 95% CI 0.67-0.76) and methadone (aHR 0.68, 95% CI 0.61-0.75), in comparison with nonpregnant status. CONCLUSION: Although a minority of reproductive-aged people with OUD in the United States are initiated on MOUD, pregnancy is associated with a significant increase in treatment initiation and a reduced risk of medication discontinuation.