Postpartum patients with a diagnosis of multiple sclerosis (MS) will be given the opportunity to enroll in this study that will evaluate the efficacy of IV natalizumab to prevent postpartum relapses. Natalizumab, administered as 300mg IV q 4 weeks, will be initiated postpartum (0-30 days post-delivery).~Patients who decline natalizumab treatment postpartum will be given the opportunity to enroll in the study in the control group. The control group will have similar inclusion and exclusion criteria as well as scheduled visit and study procedures as the active natalizumab treatment group.~The primary objective of the trial is to assess the efficacy of IV administered natalizumab, monthly for 1 year, in preventing relapses during the postpartum period.~The secondary objectives of the trial are to assess the efficacy of natalizumab in decreasing the risk for disability progression during the postpartum period and to prevent the appearance of new and/or enlarging brain MRI lesions as measured by qualitative MRI analysis.~The tertiary objective is to assess the association of the clinical outcomes with subject evaluations including patient reported outcomes.
The purpose of this study is to evaluate if monthly natalizumab, initiated after delivery, is effective in preventing postpartum relapses.