IMPORTANCE: Understanding the association between pregnancy and clinical outcomes in women with moderate to severe multiple sclerosis (MS) disability is crucial for guiding family planning and management strategies. OBJECTIVE: To assess peripregnancy relapse activity and disability progression in women with a preconception Expanded Disability Status Scale (EDSS) score of 3 or higher. DESIGN, SETTING, AND PARTICIPANTS: This multicenter retrospective cohort study used data from the MSBase Registry, with clinical observations spanning 1984 through 2024. Study cohorts included pregnant women with MS with a preconception EDSS score of 3 or higher (range: 3-10, with higher scores indicating more severe MS-related disability) and propensity score-matched nonpregnant women with MS (controls). MAIN OUTCOMES AND MEASURES: The main outcomes were peripregnancy annualized relapse rates (ARRs) and time to 6-month confirmed disability worsening (CDW). RESULTS: A total of 1631 women with MS were included, of whom 575 were in the pregnant cohort (median [IQR] age at pregnancy, 32.5 [29.1-36.1] years) and 1056 were in the nonpregnant cohort (median [IQR] age, 32.6 [27.5-37.2] years). The median (range) preconception EDSS score was 3.5 (3.0-7.5). Relapse activity decreased during pregnancy, with a 75% reduction in ARR during the first trimester (rate ratio [RR], 0.25; 95% CI, 0.15-0.43), and increased to 36% above preconception levels in the first 3 months post partum (RR, 1.36; 95% CI, 1.06-1.75). Relapse during pregnancy was associated with a higher preconception ARR (odds ratio [OR], 1.56; 95% CI, 1.10-2.20) and preconception use of natalizumab (OR, 4.42; 95% CI, 1.24-23.57) or fingolimod (OR, 14.07; 95% CI, 2.81-91.30). Older age (OR, 0.92; 95% CI, 0.85-0.99) and continuation of disease-modifying therapy into pregnancy (OR, 0.42; 95% CI, 0.19-1.00) were associated with reduced risk. Disease-modifying therapy reinitiation within 1 month post partum was associated with lower odds of early postpartum relapse (OR, 0.45; 95% CI, 0.23-0.86). There was no significant difference in time to CDW between the pregnant and nonpregnant groups (hazard ratio [HR], 1.15; 95% CI, 0.96-1.38). However, ARR during pregnancy (HR, 1.37; 95% CI, 1.13-1.65) and postpartum EDSS score higher than 4 (HR, 2.69; 95% CI, 1.80-4.03) were associated with shorter time to CDW. CONCLUSIONS AND RELEVANCE: In this cohort study, women with moderate to severe MS disability exhibited a pattern of peripregnancy relapse activity similar to that reported in women with less disability. Pregnancy was not associated with worse long-term disability outcomes, although optimizing disease control in the peripregnancy period remained critical.

• MeSH
• Adult MeSH
• Pregnancy Complications * epidemiology   MeSH
• Humans MeSH
• Disability Evaluation MeSH
• Disease Progression MeSH
• Recurrence MeSH
• Registries MeSH
• Retrospective Studies MeSH
• Multiple Sclerosis * physiopathology   drug therapy   complications   epidemiology   MeSH
• Severity of Illness Index MeSH
• Pregnancy MeSH
• Pregnancy Outcome * epidemiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH

BACKGROUND: Family planning is an important aspect of multiple sclerosis (MS), and neuromyelitis optica spectrum disorder (NMOSD) management. Knowledge gaps remain, including optimal perinatal management strategies, and fetal risks associated with disease-modifying therapy (DMT) exposure. OBJECTIVE: To describe perinatal DMT use, together with pregnancy and neonatal outcomes prospectively recorded in the International MSBase Pregnancy and Women's Health Registry. METHODS: We report summary statistics for data collected between May 2020 and August 2024. RESULTS: A total of 1887 relapsing-remitting MS (RRMS), 12 primary-progressive MS (PPMS), 2 radiologically isolated syndrome (RIS) and 21 NMOSD completed pregnancies were recorded, including 1644 (85.5%) live births, 208 (10.8%) miscarriages, and 6 (0.3%) neonatal deaths. Most women had unassisted (53.8%) or assisted (7.4%) vaginal births. Seventy five percent of pregnancies had DMT exposures within 6 months preconception; 19% of NMOSD, and 62% of MS pregnancies were DMT-exposed during gestation; 18.1% of pregnancies reported in-pregnancy monoclonal antibody DMT exposure. No overt safety signals were seen. CONCLUSION: This first report from the newly launched MSBase pregnancy registry, establishes an increasing number of pregnancies being conceived on monoclonal antibody therapies. Although no safety signals were observed, it is important to continue monitoring for safety signals in real-world databases as the use of highly effective therapies continues to increase perinatally.

• Keywords
• Multiple sclerosis, disease-modifying therapy, neonatal outcomes, neuromyelitis optica spectrum disorder, pregnancy,
• MeSH
• Adult MeSH
• Immunologic Factors * adverse effects   therapeutic use   MeSH
• Pregnancy Complications * epidemiology   drug therapy   MeSH
• Humans MeSH
• Young Adult MeSH
• Neuromyelitis Optica * drug therapy   epidemiology   MeSH
• Infant, Newborn MeSH
• Registries * statistics & numerical data   MeSH
• Multiple Sclerosis, Relapsing-Remitting drug therapy   MeSH
• Multiple Sclerosis * drug therapy   epidemiology   MeSH
• Pregnancy MeSH
• Pregnancy Outcome * epidemiology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Infant, Newborn MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Immunologic Factors * MeSH

The development of disease-modifying therapies (DMTs) for the treatment of multiple sclerosis (MS) has been highly successful in recent decades. It is now widely accepted that early initiation of DMTs after disease onset is associated with a better long-term prognosis. However, the question of when and how to de-escalate or discontinue DMTs remains open and critical. This topic was discussed during an international focused workshop organized by the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in 2023. The aim was to review the current evidence on the rationale for, and the potential pitfalls of, treatment de-escalation in MS. Several clinical scenarios emerged, mainly driven by a change in the benefit-risk ratio of DMTs over the course of the disease and with ageing. The workshop also addressed the issue of de-escalation by the type of DMT used and in specific situations, including pregnancy and paediatric onset MS. Finally, we provide practical guidelines for selecting appropriate patients, defining de-escalation and monitoring modalities and outlining unmet needs in this field.

• Keywords
• ageing, de-escalation, discontinuation, disease-modifying therapy, multiple sclerosis, pregnancy,
• MeSH
• Immunologic Factors * administration & dosage   MeSH
• Immunosuppressive Agents administration & dosage   MeSH
• Humans MeSH
• Multiple Sclerosis * drug therapy   MeSH
• Pregnancy MeSH
• Check Tag
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Immunologic Factors * MeSH
• Immunosuppressive Agents MeSH

BACKGROUND AND OBJECTIVES: Women with multiple sclerosis (MS) are at risk of disease reactivation in the early postpartum period. Ocrelizumab (OCR) is an anti-CD20 therapy highly effective at reducing MS disease activity. Data remain limited regarding use of disease-modifying therapies (DMTs), including OCR, and disease activity during peripregnancy periods. METHODS: We performed a retrospective cohort study using data from the MSBase Registry including pregnancies conceived after December 31, 2010, from women aged 18 years and older, with relapsing-remitting MS or clinically isolated syndrome. Women were classified by preconception exposure to DMTs, including OCR, rituximab (RTX), natalizumab (NAT), stratified into active (NAT-A; continued ≥28 weeks of gestation, restarted ≤1 month postpartum) or conservative (NAT-C; continued ≤4 weeks of gestation, restarted >1 month postpartum) strategies, dimethyl fumarate (DMF) or low-efficacy DMTs (interferon-beta, glatiramer acetate). Annualized relapse rates (ARRs) were calculated for 12-month prepregnancy, pregnancy, and 6-month postpartum periods. RESULTS: A total of 2,009 live births from 1,744 women were analyzed, including 73 live births from 69 women treated with preconception OCR. For OCR, no within-pregnancy relapse was observed and 3 women (4.1%) experienced 1 relapse in the postpartum period (ARR 0.09 [95% CI 0.02-0.27]). For NAT-A, 3 (3.7%) of 82 women relapsed during pregnancy (0.05 [0.01-0.15]) and 4 (4.9%) relapsed during postpartum (0.10 [0.03-0.26]). However, for NAT-C, 13 (15.9%) of 82 women relapsed within pregnancy (0.32 [0.20-0.51]) and 25 (30.5%) relapsed during postpartum (0.74 [0.50-1.06]). In the low-efficacy DMT group, 101 (7.6%) of 1,329 women experienced within-pregnancy relapse (0.12 [0.10-0.14]), followed by an increase in postpartum relapse activity with 234 women (17.6%) relapsing (0.43 [0.38-0.48]). This was similarly seen in the DMF group with 13 (7.9%) of 164 women experiencing within-pregnancy relapse (0.12 [0.06-0.20]) and 25 (15.2%) of 164 relapsing postpartum (0.39 [0.26-0.57]). Our RTX cohort had 0 of 24 women experiencing within-pregnancy relapse and 3 (12.5%) of 24 experiencing postpartum relapse. DISCUSSION: Women treated with OCR or NAT-A were observed to have low relapse rates during pregnancy and postpartum. NAT-C was associated with increased risk of relapses. There was no within-pregnancy relapse in our RTX cohort, although we caution overinterpretation due to our sample size. An effective DMT strategy with a favorable safety profile for the mother and infant should be discussed and implemented well in advance of planning a family. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that for women with relapsing-remitting MS or clinically isolated syndrome who become pregnant, ocrelizumab, rituximab, and natalizumab (continued ≥28 weeks of gestation and restarted ≤1 month postpartum) were associated with reduced risk of relapses, compared with other therapeutic strategies.

• MeSH
• Adult MeSH
• Antibodies, Monoclonal, Humanized * pharmacology   administration & dosage   MeSH
• Immunologic Factors * pharmacology   administration & dosage   MeSH
• Pregnancy Complications * drug therapy   MeSH
• Humans MeSH
• Young Adult MeSH
• Postpartum Period * MeSH
• Registries MeSH
• Multiple Sclerosis, Relapsing-Remitting drug therapy   MeSH
• Retrospective Studies MeSH
• Multiple Sclerosis drug therapy   MeSH
• Pregnancy MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Young Adult MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antibodies, Monoclonal, Humanized * MeSH
• Immunologic Factors * MeSH
• ocrelizumab MeSH Browser

Monoclonal antibodies have become a mainstay in the treatment of patients with relapsing multiple sclerosis (RMS) and provide some benefit to patients with primary progressive MS. They are highly precise by specifically targeting molecules displayed on cells involved in distinct immune mechanisms of MS pathophysiology. They not only differ in the target antigen they recognize but also by the mode of action that generates their therapeutic effect. Natalizumab, an [Formula: see text]4[Formula: see text]1 integrin antagonist, works via binding to cell surface receptors, blocking the interaction with their ligands and, in that way, preventing the migration of leukocytes across the blood-brain barrier. On the other hand, the anti-CD52 monoclonal antibody alemtuzumab and the anti-CD20 monoclonal antibodies rituximab, ocrelizumab, ofatumumab, and ublituximab work via eliminating selected pathogenic cell populations. However, potential adverse effects may be serious and can necessitate treatment discontinuation. Most importantly, those are the risk for (opportunistic) infections, but also secondary autoimmune diseases or malignancies. Monoclonal antibodies also carry the risk of infusion/injection-related reactions, primarily in early phases of treatment. By careful patient selection and monitoring during therapy, the occurrence of these potentially serious adverse effects can be minimized. Monoclonal antibodies are characterized by a relatively long pharmacologic half-life and pharmacodynamic effects, which provides advantages such as permitting infrequent dosing, but also creates disadvantages regarding vaccination and family planning. This review presents an overview of currently available monoclonal antibodies for the treatment of RMS, including their mechanism of action, efficacy and safety profile. Furthermore, we provide practical recommendations for risk management, vaccination, and family planning.

• Keywords
• Alemtuzumab, Disease-modifying therapy, Monoclonal antibodies, Multiple sclerosis, Natalizumab, Ocrelizumab, Ofatumumab, Rituximab, Ublituximab,
• MeSH
• Humans MeSH
• Antibodies, Monoclonal therapeutic use   MeSH
• Natalizumab therapeutic use   MeSH
• Antineoplastic Agents, Immunological * therapeutic use   MeSH
• Risk Management MeSH
• Multiple Sclerosis * therapy   MeSH
• Pregnancy MeSH
• Vaccination MeSH
• Check Tag
• Humans MeSH
• Pregnancy MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Antibodies, Monoclonal MeSH
• Natalizumab MeSH
• Antineoplastic Agents, Immunological * MeSH