Patterns of disease-modifying therapy utilization before, during, and after pregnancy and postpartum relapses in women with multiple sclerosis

Background: Pregnancy is a common consideration for people with multiple sclerosis (pwMS); MS onset is typically between 20 and 45 years of age, during potential child-bearing years. Pregnancy and postpartum care are a significant factor influencing disease-modifying therapy (DMT) selection for many pwMS. To date, few DMTs are considered safe to continue during pregnancy and real-world treatment patterns before, during, and after pregnancy remain uncharacterized. Evolving guidance is needed regarding how to optimize management of the pregnancy and postpartum periods considering the changing DMT landscape. This analysis in two large claims databases describes DMT utilization for the treatment of MS before, during, and after pregnancy and relapse patterns during pregnancy and postpartum. Methods: In this retrospective, observational study, the US MarketScan Commercial and Medicaid claims database was assessed for female patients aged 18-55 years with >= 1 insurance claim submitted under the diagnosis code of MS from 01 January 2016-30 April 2021 and continuous enrollment eligibility from >= 6 months prior to pregnancy date (preconception) through 6 months of follow-up following delivery (postpartum period). Comorbid conditions were examined preconception and postpartum, including anxiety and depression. Moderate/severe relapse was defined as MS-related hospitalization, or an outpatient visit and one claim within 7 days of the visit with steroids or total plasma exchange. Results: A total of 944 patients (mean [standard deviation] age, 32.4 [5.0] years) were eligible; 688 (73%) were commercially insured and 256 (27%) received Medicaid. Compared with commercially-insured patients, use of DMTs was lower among Medicaid patients at 6 months preconception (25.4% vs 40.4%; p < 0.001), with similar patterns observed both during pregnancy and postpartum. Overall, prevalence of DMT use declined sharply during pregnancy, from 36.3% of patients in the 6 months preconception to 17.9%, 5.3%, and 5.8% in trimesters 1, 2 and 3, respectively. Postpartum DMT utilization increased to 20.9% at 0-3 months and 24.4% at 4-6 months. Of all patients in the preconception period, the most frequently used DMTs were glatiramer acetate (14.3%), dimethyl fumarate (6.0%), interferon (5.2%), and natalizumab (4.9%). Due to small sample size, information was limited for anti-CD20s and alemtuzumab. The proportion of patients with any moderate/severe relapse declined over pregnancy (preconception, n = 82 [8.7%]; pregnancy, n = 25 [2.6%]), but increased postpartum (n = 94 [10.0%]). Of the 889 patients who stopped DMT during pregnancy, the risk of postpartum relapses was lower in the patients who resumed DMT postpartum (10/192) than in patients who did not (76/697) (5.2% vs 10.9%; odds ratio, 0.455 [95% confidence interval 0.216-0.860], p = 0.018). Cases of postpartum depression and anxiety were significantly lower in commercially-insured patients vs Medicaid patients (postpartum depression, 13.7% vs 27.0%, p < 0.01; postpartum anxiety, 16.3% vs 30.5%, p < 0.01). Conclusion: DMT utilization declined sharply during pregnancy; it gradually increased postpartum but remained below pre-pregnancy use. The proportion of pwMS experiencing a moderate/severe relapse and number of relapses declined over pregnancy but increased postpartum. Reinitiation of DMT during the postpartum period was associated with lower risk of relapses, supporting a role for early reinitiation of DMT postpartum.