The association between higher maternal pre‐pregnancy body mass index and increased birth weight, adiposity and inflammation in the newborn

Abstract

Summary Background Excess adiposity and adiposity‐related inflammation are known risk factors for cardiovascular disease in adults; however, little is known regarding the determinants of adiposity‐related inflammation at birth. Objectives The aim of this study was to investigate the association between maternal pre‐pregnancy BMI and newborn adiposity and inflammation. Methods Paired maternal (28‐week gestation) and infant (umbilical cord) blood samples were collected from a population‐derived birth cohort (Barwon Infant Study, n = 1074). Data on maternal comorbidities and infant birth anthropomorphic measures were compiled, and infant aortic intima‐media thickness was measured by trans‐abdominal ultrasound. In a selected subgroup of term infants ( n = 161), matched maternal and cord lipids, high‐sensitivity C‐reactive protein (hsCRP) and maternal soluble CD14 were measured. Analysis was completed by using pairwise correlation and linear regression. Because of their non‐normal distribution, pathology blood measures were log transformed prior to analysis. Results Maternal pre‐pregnancy BMI was positively associated with increased birth weight (mean difference 17.8 g per kg m −2 , 95% CI 6.6 to 28.9; p = 0.002), newborn mean skin‐fold thickness (mean difference 0.1 mm per kg m −2 , 95% CI 0.0 to 0.1; p < 0.001) and cord blood hsCRP (mean difference of 4.2% increase in hsCRP per kg m −2 increase in pre‐pregnancy BMI, 95% CI 0.6 to 7.7%, p = 0.02), but not cord blood soluble CD14. Inclusion of maternal hsCRP as a covariate attenuated the associations between pre‐pregnancy BMI and both newborn skin‐fold thickness and cord blood hsCRP. Conclusion Higher maternal pre‐pregnancy BMI is associated with increased newborn adiposity and inflammation. These associations may be partially mediated by maternal inflammation during pregnancy.