Abstract Background The role of maternal and fetal characteristics in determining kidney size in early childhood remains largely unexplored. This study aims to evaluate the association between birth weight and kidney size in children aged one to six years and explore other children and maternal determinants in a United States cohort. Methods We analyzed data from 892 mother-child pairs enrolled in the New York University Children’s Health and Environment Study (CHES). Renal sonographic measurements were taken from one to six years of age. Kidney size outcomes included average kidney length, width, depth, total kidney volume (TKV), adjusted kidney length (kidney length/body length), and adjusted TKV (TKV/body surface area). Maternal determinants include age, demographic characteristics, pre-pregnancy BMI, lifestyle, pregnancy complications, and diet during pregnancy. Fetal determinants included sex, birth weight for gestational age z-score, and gestational age at delivery. Anthropometric z change and breastfeeding duration were also considered. Associations were examined using crude and covariate-adjusted linear mixed models. Results Birth weight z-score and anthropometric z change were observed positively associated with all measures except adjusted kidney length. Female children had smaller average kidney length and TKV, and breastfeeding duration was negatively associated with average kidney depth and TKV. Children of non-Hispanic Black mothers and parous mothers had smaller kidney measures. Conclusion In NYU CHES, we found that early childhood kidney size measures were consistently influenced by birth weight z-scores and changes in postnatal weight gain z-scores. Additionally, we observed racial differences and the influence of breastfeeding duration on kidney size. Trial registration Not applicable.
Ling et al. (Tue,) studied this question.