Context: The impact of specific maternal fuels and metabolic measures during early and late gestation on neonatal body composition is not well defined.
Objective: To determine how circulating maternal glucose, lipids, and insulin resistance in the first and second halves of pregnancy influence neonatal body composition.
Design: A prospective pre-birth cohort enrolling pregnant women, the Healthy Start Study, was conducted, in which fasting maternal serum samples were collected twice during pregnancy to measure glucose, insulin, hemoglobin A1c, triglyceride, total cholesterol, high-density lipoprotein, and free fatty acids. Neonatal body composition was measured with air displacement plethysmography.
Setting: An observational epidemiology study of pregnant women attending obstetric clinics at the University of Colorado, Anschutz Medical Center.
Participants: This analysis includes 804 maternal-neonate pairs.
Results: A strong positive linear relationship between maternal estimated insulin resistance (homeostasis model of assessment for insulin resistance) in the first half of pregnancy and neonatal fat mass (FM) and FM percentage (FM%) was detected, independent of prepregnancy body mass index (BMI). In the second half of pregnancy, positive linear relationships between maternal glucose levels and offspring FM and FM% were observed, independent of prepregnancy BMI. An inverse relationship was detected between high-density lipoprotein in the first half of pregnancy and FM, independent of prepregnancy BMI. Free fatty acid levels in the second half of pregnancy were positively associated with higher birth weight, independent of prepregnancy BMI.
Conclusion: Maternal insulin resistance in the first half of pregnancy is highly predictive of neonatal FM%, whereas maternal glycemia, even within the normal range, is an important driver of neonatal adiposity in later pregnancy, independent of prepregnancy BMI. Our data provide additional insights on potential maternal factors responsible for fetal fat accretion and early development of adiposity.
Trial registration: ClinicalTrials.gov NCT02273297.