To the Editor In their article, “Exclusive breastfeeding and the effect on postpartum multiple sclerosis relapses,” Hellwig et al1 reiterated the beneficial effects of exclusive breastfeeding on women with multiple sclerosis.
Disease-modifying therapy (DMT) for multiple sclerosis has significantly changed the quality of life for patients by reducing relapse rates.2 However, it is pertinent to mention that different DMTs affect the relapse rates differently.3 The annual relapse rates vary with the use of different DMTs and, in the absence of these data, it is difficult to compare the women who exclusively breastfed with those who did not.4 We are concerned that lack of data regarding the use of DMTs in the study population may have introduced bias into the results of the study. It is possible that one cohort may have inadvertently received more efficacious DMTs than the other. In the article,1 we were not able to determine how many patients continued the use of DMT into their pregnancy, which may have a bearing on the time to first relapse.
Choudhary A, Vinny WP. Breastfeeding and Disease-Modifying Therapy for Multiple Sclerosis. JAMA Neurol. 2016;73(4):480. doi:10.1001/jamaneurol.2015.4818