Pregnancy and Multiple Sclerosis Disease Activity in Women from the New York State Multiple Sclerosis Consortium

Background: Multiple sclerosis (MS) is the most common cause of disability in young adults and women of childbearing age. A substantial portion of women with MS will intend to become pregnant after diagnosis. Though, for many, pregnancy is a time of relative disease quiescence, relapse rates are high postpartum. Additional information is needed about disease activity and disease modifying therapy (DMT) usage before, during and after pregnancy. 

Objectives: To investigate the relationship between relapse rates and reproductive events among women with MS and report on DMT use during pregnancy and clinical and birth outcomes.

Methods: A detailed reproductive questionnaire was distributed to women enrolled in the New York State Multiple Sclerosis Consortium (NYSMSC) from 1/1/2012-6/1/2017. In total, 1,651 women with MS were queried about their reproductive history and reproductive decision-making. Six hundred thirty-five (635) women agreed to participate (38.4% response rate) and completed the questionnaire.  Their data was also linked with long-term outcomes from the NYSMSC registry.

Results: Of the 516 patients with available pregnancy data, 109 (21.1%) reported a pregnancy after being diagnosed with MS. Relapses were reported by 53 (48.6%) in the 24-months prior to pregnancy. Relapses were infrequent during pregnancy (n=13, 11.9%), but when observed, were more common in the first or second trimester compared to the third trimester. During the 24-month period after birth, 49 (45.8%) patients experienced a relapse, most (n=31) within a year of delivery. Patients who had a relapse during the 24-months prior to pregnancy were more likely to report a relapse in the 24-month postpartum period as well (61.7%, p=.011). In contrast, relapses during pregnancy were not associated with postpartum relapse activity (13.0%, p=.908). Eleven (16.2%) women continued using DMTs during their pregnancy, 6 of which continued throughout their whole pregnancy. The vast majority of patients who used a DMT before pregnancy resumed after giving birth (59, 76.6%), and half of the patients did so within 3 months of delivery (30, 50.8%). None of the patients who continued DMTs reported birth problems or were referred to special medical services when their child reached age 1 or 2. 

Conclusions: Data collection is complete and preliminary findings are presented. Additional results, including the long-term effects of pregnancy in MS, will be available at the time of the presentation.