Associations of maternal weight status prior and during pregnancy with neonatal cardiometabolic markers at birth: the Healthy Start study

BACKGROUND: Maternal obesity increases adult offspring risk for cardiovascular disease; however, the role of offspring adiposity in mediating this association remains poorly characterized. OBJECTIVE: To investigate the associations of maternal pre-pregnant body mass index (maternal BMI) and gestational weight gain (GWG) with neonatal cardiometabolic markers independent of fetal growth and neonatal adiposity. METHODS: A total of 753 maternal-infant pairs from the Healthy Start study, a large multiethnic pre-birth observational cohort were used. Neonatal cardiometabolic markers included cord blood glucose, insulin, glucose-to-insulin ratio (Glu/Ins), total and high-density lipoprotein cholesterol (HDL-c), triglycerides, free fatty acids and leptin. Maternal BMI was abstracted from medical records or self-reported. GWG was calculated as the difference between the first pre-pregnant weight and the last weight measurement before delivery. Neonatal adiposity (percent fat mass) was measured within 72 h of delivery using whole-body air-displacement plethysmography. RESULTS: In covariate adjusted models, maternal BMI was positively associated with cord blood insulin (P = 0.01) and leptin (P < 0.001) levels, and inversely associated with cord blood HDL-c (P = 0.05) and Glu/Ins (P = 0.003). Adjustment for fetal growth or neonatal adiposity attenuated the effect of maternal BMI on neonatal insulin, rendering the association nonsignificant. However, maternal BMI remained associated with higher leptin (P < 0.0011), lower HDL-c (P = 0.02) and Glu/Ins (P = 0.05), independent of neonatal adiposity. GWG was positively associated with neonatal insulin (P = 0.02), glucose (P = 0.03) and leptin levels (P < 0.001) and negatively associated with Glu/Ins (P = 0.006). After adjusting for neonatal adiposity, GWG remained associated with higher neonatal glucose (P = 0.02) and leptin levels (P = 0.02) and lower Glu/Ins (P = 0.048). CONCLUSIONS: Maternal weight prior and/or during pregnancy is associated with neonatal cardiometabolic makers including leptin, glucose and HDL-c at delivery, independent of neonatal adiposity. Our results suggest that intrauterine exposure to maternal obesity influences metabolic processes beyond fetal growth and fat accretion.