Exclusive breastfeeding and the effect on postpartum multiple sclerosis relapses

Women with multiple sclerosis (MS) who intended to breastfeed their infants exclusively for two months had a lower risk of relapse during the first six months after giving birth compared with women who did not breastfeed exclusively , according to an article published online by JAMA Neurology.

About 20 percent to 30 percent of women with MS experience a relapse within the first three to four months after giving birth and there are no interventions for effective prevention of postpartum relapse. The effect of exclusive breastfeeding on postpartum risk of MS relapse is controversial with conflicting study results.

Kerstin Hellwig, M.D., of Ruhr-University Bochum, Germany, and coauthors analyzed data from 201 pregnant women with MS collected from 2008 to June 2012 with one-year follow-up postpartum in the nationwide German MS and pregnancy registry. Exclusive breastfeeding was defined as no regular replacement of breastfeeding meals with supplemental feedings for at least two months compared with nonexclusive breastfeeding, which was partial or no breastfeeding.

Of the 201 women, 120 (59.7 percent) intended to breastfeed exclusively for at least two months, 42 women (20.9 percent) combined breastfeeding with supplemental feedings within the first two months after giving birth, and 39 women (19.4 percent) did not breastfeed. Most women [178 (88.6 percent)] had used disease-modifying therapy (DMT) agents before pregnancy.

The authors report that 31 women (38.3 percent) who did not breastfeed exclusively had MS relapse within the first six months postpartum compared with 29 women (24.2 percent) who intended to breastfeed exclusively for at least two months.

The authors note the effect of exclusive breastfeeding "seems to be plausible" since disease activity returned in the second half of the postpartum year in exclusively breastfeeding women, corresponding to the introduction of supplemental feedings and the return of menstruation. The introduction of regular formula feedings or solid food to an infant leads to a change in a woman's hormonal status resulting in the return to ovulation.

The authors note the main limitation of their study was the selection bias inherent to voluntary registries and reflected in the high proportion of women receiving DMT.

"Taken together, our findings indicate that women with MS should be supported if they choose to breastfeed exclusively since it clearly does not increase the risk of postpartum relapse. Relapse in the first six months postpartum may be diminished by exclusive breastfeeding, but once regular feedings are introduced, disease activity is likely to return," the study concludes.