NEW YORK (Reuters Health) – Breastfeeding appears to protect against postpartum multiple sclerosis (MS) relapses, according to a fresh look at past research.
“Breastfeeding did not appear harmful, and may be protective against MS relapses,” Dr. Kristen M. Krysko of the University of California, San Francisco, told Reuters Health by email. “Women with MS should therefore be encouraged to breastfeed exclusively when possible.”
MS relapse rates increase in the three months after a woman has given birth, when up to 30% of women have a relapse. A 2012 meta-analysis suggested that women who did not breastfeed were more likely to have a postpartum relapse than those who did breastfeed, but the association remains unclear.
Dr. Krysko’s team sought to determine whether breastfeeding is associated with a reduction in postpartum MS relapses in their systematic review and meta-analysis of 24 studies (11 published after 2012) including nearly 3,000 women.
The definition of breastfeeding varied across studies, and all studies were rated as having moderate or serious risk of bias, the researchers report in JAMA Neurology.
Among 15 studies, the pooled odds of postpartum MS relapse were 37% lower in breastfeeding women (P=0.006). Similarly, among four studies reporting adjusted hazard ratios, the risk of postpartum MS relapse was 43% lower with breastfeeding (P=0.006).
The apparent protective effects of breastfeeding were stronger in studies of exclusive breastfeeding for two months, and the putative benefits appeared to persist through six months postpartum.
“Since all included studies are observational design, residual confounding is possible, and it is possible that women with lower disease activity were those who chose to breastfeed,” Dr. Krysko said. “However, even when limiting to higher-quality studies with adjustment for confounders, a benefit was seen.”
“Given the lack of a harmful effect of breastfeeding on MS and potential benefit, I think we should encourage mothers with MS to breastfeed, and to breastfeed exclusively when possible, allowing mothers with MS and their infants to benefit from breastfeeding,” she said.
“However,” Dr. Krysko said, “it is important to note that even in the breastfeeding groups in these studies, the risk of postpartum relapse remained high. This highlights the need for better understanding of the safety of MS medications while breastfeeding so that MS management can be optimized to decrease relapse risk in the mother while allowing the benefits of breastfeeding to the mother and infant.”
“Further study of this is needed,” she said. “Postpartum MS treatment planning should be individualized with discussion between the woman and her neurologist.”