Effect of mode of delivery on macronutrient content of breast milk

Objective: To determine the effect of delivery type on macronutrient content of colostral milk. Materials and methods: The study was conducted at Zekai Tahir Burak Maternity Teaching Hospital. Colostral milk samples from term lactating mothers who gave birth by vaginal or cesarean delivery (CD) were obtained on the 2nd postpartum day. Milk protein, fat, carbohydrate (CHO) and energy levels were measured by using a mid-infrared human milk analyzer. Results: A total of 204 term lactating mothers were recruited to the study; 111 mothers gave birth by vaginal route and 93 mothers by CD. Protein levels were statistically lower in colostral milk of mothers after CD compared to mothers who delivered vaginally (median 2.4 (range 0.3-6.4) g/dl versus 3 (0.5-6.3) g/dl, respectively; p 0.036). Colostral fat, CHO and energy levels were similar between groups. In linear regression analysis, CD and maternal age were independently associated with lower protein content in colostrum. Conclusion: Vaginal delivery is associated with higher colostrum protein content. Hormonal activity induced by labor pain and uterine contractions might account for the alterations in the protein composition of human milk to facilitate optimal development of important physiologic functions in newborns.