2140-P: Differential Fatty Acids in Human Milk from Individuals with Gestational Diabetes

Introduction and Objective: Human milk (HM) fatty acids (FA), which are critical for infant development, show wide inter-individual variability, but the impact of maternal metabolic health on HM FA profiles remain unclear. Our objective was to evaluate differences in HM FA between lactating mothers who had been diagnosed with gestational diabetes mellitus (GDM) and those without GDM. Methods: HM samples were collected at 3 months post-partum from participants in two centers, Minnesota and Oklahoma, in the MILk Study (NIHR01HD080444). MILk included women aged 21-45 years; pre-pregnancy BMI 18.5-45.0 kg/m2; singleton full-term pregnancy; intention to breastfeed. Cohort selection for this analysis ensured one third of participants had GDM, although data on GDM treatment was not available. HM was stored at -80°C until FA analysis by GC-MS to measure relative concentrations of 24 FA, reported as the percent of total FA measured (FA%). The primary FA of interest was docosahexaenoic acid (DHA; 22:6n3). Linear regression models evaluated the associations between GDM status and HM FA. Adjustments included maternal BMI, parity, maternal use of omega(n)3 FA supplements and study center. Results: Of the 100 participants (n=32 with GDM), maternal age was 32.4±4.2 years, pre-pregnancy BMI 27.7±5.7 kg/m2 and 38% were nulliparous. Most participants (80%) used n3 FA supplements. Mean dietary n3 FA intake was 1.59±0.83 g/d with no difference by GDM. Milk from mothers with GDM had lower DHA (ß=-0.07, 95% CI (-0.14,-0.01) FA%; p=0.029) which was attenuated in fully adjusted models (ß=-0.035 (-0.10,0.03). Milk oleic acid (18:1n9) was lower in GDM in adjusted models (ß=-2.28 (-4.44,-0.12); p=0.039). GDM was associated with higher FA 15:0, 17:1, 20:1n9, 20:4n6, and lower FA 12:0, 18:3n6, 22:4n6, 22:5n6, 24:0 in adjusted models. The n6:n3 FA ratio did not differ by GDM status. Conclusion: Maternal GDM is associated with altered HM FA profiles. These findings suggest implications of GDM extend beyond gestation well into the lactation period. Disclosure J. Josefson: None. B. Gregg: Consultant; Current; CVS Health. D. Robinson: Research Support; Current; Abbott. Speaker's Bureau; Ended; Baxter.