Exclusive Breastfeeding and the Effect on Postpartum Multiple Sclerosis Relapses

IMPORTANCE Women with multiple sclerosis (MS) experience an elevated risk of relapse after giving birth. The effect of exclusive breastfeeding on postpartum risk of MS relapse is unclear. OBJECTIVES To determine the effect of exclusive breastfeeding on postpartum risk of MS relapse and to investigate the effect of introducing supplemental feedings on that risk. DESIGN, SETTING, AND PARTICIPANTS Data on 201 pregnant women with relapsing-remitting MS were collected prospectively from January 1, 2008, to June 30, 2012, with 1 year follow-up post partum in the nationwide German MS and pregnancy registry. The effect of the intention to breastfeed exclusively (no regular replacement of breastfeeding meals with supplemental feedings) for at least 2 months compared with nonexclusive breastfeeding (partial or no breastfeeding) on the first postpartum MS relapse, using Cox proportional hazards regression model adjusted for age and disease activity, before and during pregnancy was analyzed. Data analysis was performed from August 30, 2013, to May 25, 2015. EXPOSURE Exclusive breastfeeding defined as at least 2 months of breastfeeding without regular replacement of any meal by supplemental feeding. MAIN OUTCOME AND MEASURE First postpartum MS relapse. RESULTS Of 201 women, 120 (59.7%) intended to breastfeed exclusively for at least 2 months and 81 (40.3%) breastfed and included supplemental feeding (42 [20.9%]) or did not breastfeed (39 [19.4%]). Thirty-one women (38.3%) who did not breastfeed exclusively had a relapse within the first 6 months post partum compared with 29 women (24.2%) who intended to breastfeed exclusively for at least 2 months (unadjusted hazard ratio, 1.80; 95% CI, 1.09-2.99; P = .02; adjusted hazard ratio, 1.70; 95% CI, 1.02-2.85; P = .04). The time to first postpartum relapse after the introduction of supplemental feedings did not differ significantly between women who previously breastfed exclusively and those who did not (P = .60). CONCLUSIONS AND RELEVANCE The findings of this study suggest that exclusive breastfeeding is a modestly effective MS treatment with a natural end date. Our study provides further evidence that women with MS who breastfeed exclusively should be supported to do so since it does not increase the risk of postpartum relapse.