Multiple Sclerosis

MS: Does Pregnancy Increase Relapse Risk?

Pregnancy is likely not associated with an increased risk of relapse among most women with multiple sclerosis (MS), and exclusive breastfeeding may help reduce early postpartum relapse risk, according to new findings.

Researchers arrived at their conclusion after prospectively collecting 2008-2016 electronic health record data from Kaiser Permanente Southern and Northern California on mothers and infants related to treatment history, breastfeeding, and relapses. The researchers utilized multivariable models to account for measures of disease severity.

The results of the study indicated that 26.4% of women experienced a relapse, 87% of women breastfed, 36% of women breastfed exclusively for at least 2 months, and 58.8% of women did not use disease-modifying therapies (DMTs) during the postpartum year.

Approximately 67.2% of women had suboptimally controlled disease at the onset of pregnancy. Annualized relapse rates (ARRs) were found to decrease from 0.37 prior to pregnancy to 0.14 to 0.07 during pregnancy, and no rebound disease activity was observed in the postpartum period. During the first 3 months postpartum, the ARR was 0.27. By 4 to 6 months postpartum, the ARR had returned to pre-pregnancy rates.

Exclusive breastfeeding was associated with a decreased risk of early postpartum relapses (adjusted hazard ratio 0.37), whereas measures of disease severity were associated with an increased risk. The researchers noted that resuming modestly effective DMTs did not affect risk (time-dependent covariate).

“Most women diagnosed with MS today can have children without incurring an increased risk of relapses,” the researchers concluded. “Women with suboptimal disease control before pregnancy may benefit from highly effective DMTs that are compatible with pregnancy and lactation. Women with MS should be encouraged to breastfeed exclusively,” they wrote.

—Christina Vogt

Langer-Gould A, Smith JB, Albers KB, et al. Pregnancy-related relapses and breastfeeding in a contemporary multiple sclerosis cohort. Neurology. 2020;94(18). doi:10.1212/WNL.0000000000009374