Association between breastfeeding and postpartum multiple sclerosis relapses: a systematic review and meta-analysis.
Krysko KM, Rutatangwa A, Graves J, Lazar A, Waubant E.
JAMA Neurol 2019 (Epub ahead of print).
Multiple sclerosis (MS) relapses may be increased in the postpartum period, and whether breastfeeding is associated with reduction in the risk of postpartum relapses remains controversial.
PubMed and Embase were searched for studies assessing the association between breastfeeding and MS disease activity published between January 1, 1980, and July 11, 2018, as well as reference lists of selected articles.
The search identified 462 unique citations, and 24 (2974 women) satisfied eligibility criteria and were included, of which 16 were included in the quantitative meta-analysis. The pooled summary odds ratio for the association of breastfeeding with postpartum relapses was 0.63 (95% CI, 0.45-0.88; P = .006) compared with a reference of nonbreastfeeding. Pooled adjusted hazard ratio across 4 studies that reported this finding was 0.57 (95% CI, 0.38-0.85; P = .006). There was moderate heterogeneity (I2 = 48%), which was explained by variable prepregnancy relapse rate, postpartum follow-up duration, and the publication year. A stronger association was seen in studies of exclusive rather than nonexclusive breastfeeding, although both demonstrated an association. Studies were rated at moderate and serious risk of bias, with concern for residual confounding, although sensitivity analysis including only moderate quality studies was consistent with a protective outcome of breastfeeding.
These findings suggest that breastfeeding is protective against postpartum relapses in multiple sclerosis, although high-quality prospective studies to date are limited and well-designed observational studies that aim to emulate a randomized trial would be of benefit.