1399-P: The Accumulative Impact of Insulin Sensitivity throughout Pregnancy on Neonatal Fatness

Aim: To evaluate the direct and indirect associations between insulin sensitivity during pregnancy and neonatal fatness.

Methods: This is a longitudinal, secondary analysis of the DALI study which was a multicenter study conducted in nine European countries. Pregnant women with a pre-pregnancy body mass index (BMI) of ≥29 kg/m2, <20 weeks of gestation, a singleton pregnancy, and aged ≥18 years were invited to participate. Women diagnosed with early gestational diabetes were excluded. Neonatal fatness was estimated by the sum of triceps, subscapular, supra iliac and quadriceps skinfolds. Maternal insulin sensitivity (HOMA), fasting glucose, triglycerides (TG) and free fatty acids (FFA) were measured three times during pregnancy (13-20, 24-28, and 35-37 weeks of gestation). Structured equation modelling was performed to evaluate the direct and indirect relationship between variables of interest. Analysis was adjusted for maternal ethnicity, maternal education, maternal age, gestational age and neonatal age and results were presented in standard deviations (SD).

Results: In total, 701 mother-infant pairs (51.0% boys) were included. Neonatal girls exhibited higher sum of skinfolds compared to boys (20.5 mm [±5.5] vs. 21.6 mm [±5.3]; p=0.03). HOMA at 13-20 weeks but not at 24-28 or 35-37 weeks was associated with neonatal fatness. This association was mediated through Glucose_13-20weeks -> Glucose_24-28weeks -> Glucose_35-37weeks (0.599 SD for boys and 0.467 SD for girls) and TG_13-20weeks -> TG_24-28weeks -> TG_35-37weeks (0.464 SD for boys and 0.497 SD for girls). The pathway with FFA did not mediate the association between HOMA and neonatal fatness.

Conclusions: Maternal health profile in the first trimester of pregnancy plays an important role in neonatal body fatness, since insulin sensitivity was associated with neonatal fatness via increases in HOMA-Index, glucose and triglycerides throughout pregnancy.