Abstract
Introduction: Family planning is an integral aspect in the care of women with multiple sclerosis (MS). As disease-modifying therapy (DMT) discontinuation may increase relapse activity, treatment benefits need to be carefully balanced against the risk to the unborn. Ocrelizumab may be a suitable option for women with MS who are planning to conceive, but real-world data on disease activity during pregnancy and postpartum versus other DMTs are scarce.
Objectives/Aims: To describe relapse activity in women with MS before, during and after pregnancy treated with ocrelizumab versus other DMTs.
Methods: Pregnancies in women with MS recorded in MSBase since 2011 up to 1st March 2023 treated with ocrelizumab (OCR), natalizumab (NAT), dimethyl fumarate (DMF) or low-efficacy DMT (interferon-beta, glatiramer acetate) before pregnancy were included. Annualised relapse rates (ARR) were calculated per three-month period for the one-year preconception, during and after pregnancy.
Results: A total of 1654 women with 1901 pregnancies were included (OCR, n=58; NAT, n=398; DMF, n=156; low-efficacy DMT, n=1289). For NAT, use was further subset into continuation into pregnancy third trimester with early (⩽1 month) postpartum re-initiation (NAT-E, n=77)), and cessation prior to four-weeks gestation with late postpartum re-initiation (NAT-L, n=79). One-year preconception ARR [95% CI] was 0.15 [0.06-0.30] for OCR; 0.11 [0.08-0.15] for NAT; 0.12 [0.07-0.19] for DMF; and 0.22 [0.19-0.25] for low-efficacy DMT. During pregnancy, ARR [95% CI] was 0 [0-0.09] for OCR; 0.04 [0-0.13] for NAT-E; 0.34 [0.20-0.52] for NAT-L; 0.12 [0.07-0.21] for DMF; and 0.12 [0.10-0.14] for low-efficacy DMT. Postpartum ARR [95% CI] was 0.11 [0.02-0.33] for OCR; 0.11 [0.03-0.28] for NAT-E; 0.77 [0.52-1.11] for NAT-L; 0.41 [0.28-0.59] for DMF; and 0.43 [0.38-0.49] for low-efficacy DMT. Three women treated with ocrelizumab preconception experienced a postpartum relapse, two of which occurred prior to ocrelizumab re-initiation; none of these women had relapses pre-conception or during pregnancy.
Conclusion: This real-world analysis suggests that women with MS receiving ocrelizumab pre-conception are likely at low risk for within-pregnancy relapse and not at increased risk of postpartum relapses. However, treatment pauses after birth may increase relapse risk. Further data including predictors of postpartum relapses are warranted to ensure optimal care to women with MS and their infants.