Maternal Adipose Tissue Expansion, A Missing Link in the Prediction of Birth Weight Centile

Abstract

Context: Maternal body mass index (BMI) is associated with increased birth weight but does not explain all the variance in fetal adiposity. Objective: To assess the contribution of maternal body fat distribution to offspring birth weight and adiposity. Design: Longitudinal study throughout gestation and at delivery. Setting: Women recruited at 12 weeks of gestation and followed up at 26 and 36 weeks. Cord blood was collected at delivery. Patients: Pregnant women (n = 45) with BMI 18.0 to 46.3 kg/m2 and healthy pregnancy outcome. Methods: Maternal first trimester abdominal subcutaneous and visceral adipose tissue thickness (SAT and VAT) was assessed by ultrasound. Main Outcome Measures: Maternal body fat distribution, maternal and cord plasma glucose and lipid concentrations, placental weight, birth weight, and fetal adiposity assessed by cord blood leptin. Results: VAT was the only anthropometric measure independently associated with birth weight centile (r2 adjusted 15.8%, P =. 002). BMI was associated with trimester 2 and trimesters 1 through 3 area under the curve (AUC) glucose and insulin resistance (Homeostatic Model Assessment). SAT alone predicted trimester 2 lipoprotein lipase (LPL) mass (a marker of adipocyte insulin sensitivity) (11.3%, P =. 017). VAT was associated with fetal triglyceride (9.3%, P =. 047). Placental weight was the only independent predictor of fetal adiposity (48%, P