Pregnancy and multiple sclerosis in the DMT era: A cohort study in Western Austria

Background: Multiple sclerosis (MS) predominantly affects women of child-bearing potential. Pregnancy in MS is still a controversial issue lacking standardized treatment recommendations. Objective: To examine the reciprocal effects of pregnancy, MS, and disease-modifying treatment (DMT). Methods: We analyzed 387 pregnancies in 239 women with relapsing remitting multiple sclerosis (RRMS) and > 1 pregnancy, establishment of diagnosis >1 year before conception, and > 2 years of follow-up after delivery. Relapse rates and Expanded Disability Status Scale (EDSS) scores were compared in the year before conception, during pregnancy, and 2 years postpartum. Binary logistic regression was used to investigate predictors of risk for relapses and disability progression during pregnancy and postpartum. Results: Risk of relapse and disability progression during pregnancy was predicted by pre-conception relapse activity, higher EDSS score at conception, use of highly effective disease-modifying treatment (H-DMT) pre-conception, and prolonged washout period. Postpartum relapse and disability progression was associated with relapse activity pre-conception and during pregnancy and use of H-DMT pre-conception. Early restart of DMT reduced the risk of postpartum relapse. Conclusion: A personalized approach in planning pregnancy in women with MS while on H-DMT needs to be adopted. It seems reasonable maintaining natalizumab closer to conception and restarting the drug early postpartum to reduce the considerable risk of disease reactivation during early pregnancy and after delivery.