788 Can urinary metabolite markers at 12-20 weeks’ gestation be used to predict birthweight?

Abstract

To examine if urinary metabolites are predictive of birthweight. Urine samples were collected at 12-20 weeks’ from 126 women participating in the Mothers, Omega 3 & Mental Health Study, a double blind, placebo-controlled randomized controlled trial of omega-3 fatty acid supplementation for pregnant women identified at high risk for depression. Delivery birthweights were available for 112 of the participants and classified as small for gestational age (SGA, n=9), appropriate for gestational age (AGA, n=84) and large for gestational age (LGA, n=19). Urine samples underwent ion pairing reverse phase LC-MS analysis for 49 metabolites. Principle component analysis (PCA) was used to determine if there was a relationship between individual metabolites and weight classification. Means of each metabolite were calculated for each birthweight group and were statistically compared using T tests. In the SGA group, we found increased mean concentrations of urinary gluconate (P=0.046), inosine (P=0.020), and a-hydroxyisobutyrate (P=0.043) as well as decreased concentration of hypoxanthine (P=0.021) when compared with the mean urinary concentrations of these metabolites among mothers who gave birth to AGA infants. There were no significant differences between mean metabolite concentrations in the LGA and AGA groups. Our exploratory study found four early pregnancy urinary metabolites (gluconate, inosine, a-hydroxyisobutyrate, hypoxanthine) to be correlated with later SGA birthweight. Further research is warranted to evaluate whether these markers may identify women at risk of delivering SGA neonates. Earlier detection may impact pregnancy care and antenatal fetal surveillance. This may be particularly important for gravid woman at risk for developing depressive symptoms.