MS is a complex polygenic disease with over 200 associated genetic variants. The risk of an offspring developing MS if one parent is affected is relatively low at 2% to 3% (though maternal transmission shows slightly higher heritability), with some possible epigenetic influences. The National Multiple Sclerosis Society reports that up to 4 times as many women have MS as men. The average age at MS diagnosis is around 30 years. Studies show this ratio has grown over the past several decades; in the mid-20th century, the ratio was roughly 2:1, but the proportion of affected females has steadily increased due to a combination of environmental, hormonal, and diagnostic factors. MS does not impair natural fertility, so OB providers should be aware of the effect of pregnancy on MS and vice verse. In this episode, we will review a brand new (as of Aug 8, 2026) expert review on the subject which was published in the AJOG. Over the last decade, clinical guidance has shifted from advising women with MS to avoid pregnancy to a more active and permissive stance, largely due to the advent of new pharmacological and biologic therapies. Listen in for details.
1. Balshi A, et al. Management of Multiple Sclerosis During Pregnancy and the Reproductive Years in 2026: An Expert Clinical Review, American Journal of Obstetrics and Gynecology (2026), doi: https://doi.org/10.1016/j.ajog.2026.08.043.