Key clinical point: Pregnancy and childbirth seem to delay the onset of multiple sclerosis by more than 3 years. However, having more pregnancies is not associated with later onset.
Major finding: Onset of clinically isolated syndrome (CIS) was later in women with previous pregnancies and childbirths vs. those without pregnancies and childbirths (hazard ratio, 0.68; P less than .001), with a median delay of 3.3 years. No association was seen between higher number of pregnancies and childbirths and delay in CIS onset.
Study details: The findings are based on a multicenter cohort study of 2,557 women with CIS (mean age at CIS onset, 31.5 years) from the MSBase Registry.
Disclosures: The study was supported by a postgraduate scholarship and Ian Ballard Travel Award from MS Research Australia, an Australian Government Research Training Program Scholarship, and a grant from the National Health and Medical Research Council. The lead author reported receiving grants from MS Research Australia during the conduct of the study; grants, personal fees, and nonfinancial support from Biogen; grants and personal fees from Merck Serono; personal fees from Teva and Novartis; and nonfinancial support from Roche and Genzyme-Sanofi outside the submitted work.
Citation: Nguyen AL et al. JAMA Neurol. 2020 Sep 14. doi: 10.1001/jamaneurol.2020.3324 .