Associations of maternal plasma and infant umbilical cord blood plasma metabolomics profiles with anthropometric measures at birth: a prospective cohort study.

Background: The metabolomics profiles of maternal plasma during pregnancy and cord plasma at birth might influence fetal growth and birth anthropometry. The objectives of this study are to examine how metabolites measured in maternal plasma samples collected during pregnancy and umbilical cord plasma samples collected at birth are associated with newborn anthropometric measures, a known predictor of future health outcomes. Methods: Pregnant women between 24 and 28 weeks of gestation were recruited from prenatal clinics in New Hampshire as part of a prospective cohort study. Blood samples from 413 women at enrollment and 787 infant cord blood samples were analyzed using the Biocrates AbsoluteIDQ® p180 kit . Multivariable linear regression models were used to examine association of cord and maternal metabolites with infant anthropometry at birth. Results: In cord blood samples, several acylcarnitines, a phosphatidylcholine, and a custom metabolite indicator were negatively associated with birth weight Z-score, and lysophosphatidylcholines as well as three custom metabolite indicators were positively associated with birth weight Z-score. Acylcarnitine C5 was negatively associated with birth length Z-score, and several lysophosphatidylcholines and a custom metabolite indicator were positively associated with birth length Z-score. Maternal blood metabolites did not show significant associations with birth weight and length Z scores, however, a custom metabolite indicator, the ratio of kynurenine over tryptophan, was negatively associated with weight-for-length Z-score. Conclusions: Several cord blood metabolites associated with newborn weight and length Z-scores; in particular, consistent findings were observed for several acylcarnitines that play a role in utilization of energy sources, and a lysophosphatidylcholine that is part of oxidative stress and inflammatory response pathways. Fewer associations were observed with maternal metabolomic profiles.