Maternal metabolic risk factors and their association with birthweight and cord blood insulin

Objective To quantify the inter-dependency between maternal metabolic risk factors and their association with birthweight and cord blood insulin (CBI) level. Design Prospective cohort study. Setting Guangzhou Women and Children’s Medical Centre (GWCMC). Population Pregnant women with a singleton pregnancy who delivered at GWCMC between Jan 2015 and Jun 2016 and had umbilical cord blood retained (total 1522). Methods Multivariable linear regression and Additive Bayesian Network analysis were used to investigate the association between maternal metabolic risk factors (pre-pregnancy body mass index [BMI], fasting glucose, lipid profiles, and early gestational weight gain [GWG]) and their interdependency in predicting birthweight and CBI concentrations. Main outcome measures Birthweight and cord blood insulin. Results High maternal pre-pregnancy BMI was strongly associated with neonatal birthweight (standardized adjusted regression coefficient [βstd] = 0.27, 95%CI 0.22-0.32) directly; and with CBI indirectly. Maternal fasting glucose was positively associated with increased CBI (βstd=0.12, 95%CI 0.07-0.17). Maternal GWG was positively associated with increased birthweight, but not with CBI. None of the maternal lipids profile was independently associated with birthweight or CBI. Conclusions Maternal pre-pregnancy overweight/obesity is the most influential upstream metabolic risk factor for both maternal and neonatal metabolic health, therefore weight management should be addressed from the preconception period. Maternal dyslipidaemia appears to be secondary to maternal metabolic dysfunction with no clear causality relationship with metabolic adverse outcomes in neonates.