Differences in Human Milk Lactose and Citrate Concentrations Based on Gestational Diabetes Status

Exclusive breastfeeding is the optimal manner of early infant nutrition but women with gestational diabetes mellitus (GDM) often experience challenges with lactation in the early postpartum period. Increases in the colostral metabolites of lactose and citrate have been found to indicate increased milk production. A follow-up study of 133 postpartum women with and without GDM was conducted to examine differences in specific colostral metabolite levels using enzymatic methods to determine transition to lactogenesis II during the first week postpartum. We used linear mixed models for repeated measures over time to examine the effect of GDM on colostral metabolite levels at baseline and follow-up with fixed effects of GDM status, time, covariates, and interactions between time and GDM, between time and time, and between time, time and GDM into the model allowing quadratic trends over time. Over time, lactose and citrate levels increased for all mothers (p < 0.001 and p < 0.001, respectively), although mothers with GDM had consistently lower lactose and citrate levels compared with nondiabetic mothers (p = 0.004 and p = 0.014, respectively). Age, prepregnancy body mass index, mode of birth, and parity did not independently influence colostral concentrations of lactose and citrate. Findings suggest that the rate of change overtime in lactose and citrate concentrations differ by GDM status. Further research examining the trajectory of colostral metabolite levels by GDM status is warranted.