Treatment of Women with Multiple Sclerosis Planning Pregnancy

Purpose of Review We review data available for treatment of multiple sclerosis (MS) before, during, and after pregnancy. We present recent data on disease-modifying therapies (DMT) before/during pregnancy and while breastfeeding, with treatment recommendations. Recent Findings Observational data support the safety of injectable DMTs (glatiramer acetate, interferon-beta) for use in pregnancy, while some oral DMTs might be associated with fetal risk. Monoclonal antibodies (mAbs) before pregnancy such as rituximab or natalizumab likely do not pose significant fetal risks, but can cross the placenta with neonatal hematological abnormalities if given in the second trimester or later. Breastfeeding is associated with decreased risk of postpartum relapses. Finally, injectables and mAbs likely have low transfer into breastmilk. Many women with MS do not require DMTs during pregnancy, although injectables could be continued. For women with highly active MS, cell-depleting therapies could be given before conception, or natalizumab could be continued through pregnancy, with monitoring of the fetus. Women should be encouraged to breastfeed, and those with higher relapse risk could consider injectables or mAbs while breastfeeding. Further data on safety of DMTs around pregnancy are needed. Maximizing function through non-pharmacologic approaches is complementary to DMTs. Special considerations for pregnancy and DMTs during the COVID-19 pandemic are needed.