Gestational Diabetes Mellitus, Human Milk Composition, and Infant Growth

Background: Gestational diabetes mellitus (GDM) is known to affect human milk composition. Aims of this study were to compare macronutrient and energy content of human milk of women with (GDM⁺) and without GDM (GDM^-), to assess the association between maternal health and human milk macronutrient and energy content and association between human milk macronutrient and energy content and infant growth. Study Design and Methods: Two months after delivery, hindmilk samples were collected. Triglyceride (TG), lactose, and protein content of human milk were measured. An oral glucose tolerance test was performed. Infant weight and length at birth and 2 months were collected. Weight-for-age (WAZ) and weight-for-length z-scores were calculated. Results: Twenty-four GDM⁺ and 29 GDM^- women were included. Protein, lactose, and energy content of human milk were similar between groups. TG concentration was higher in GDM⁺ than in GDM^- women (6.3 ± 2.0 versus 5.3 ± 1.2, p = 0.04). This difference was no longer significant after adjustment for maternal age and infant sex (p = 0.23). Maternal age was associated with TG (r = 0.28, p = 0.04) and lactose (r = -0.30, p = 0.03), while fasting glucose was associated with proteins (r = 0.30, p = 0.03) and tended to be associated with TG (r = 0.27, p = 0.05) and energy (r = 0.24, p = 0.08). TG levels in human milk were associated with weight (β: 0.26, 95% confidence interval [CI]: 0.02 to 0.50) and WAZ (β: 0.40, 95% CI: 0.05 to 0.75) at 2 months among children unexposed (GDM^-) to GDM, but not among children exposed (GDM⁺) Conclusions: In conclusion, GDM status, maternal age, and fasting glucose level were associated with human milk composition. Finally, TG in human milk was associated with infant growth among GDM^- children but not among GDM⁺ children. ClinicalTrials.gov NCT02872402.