NIEHS seeks to characterize longitudinal pathways of inflammation in pregnancy using metabolomics in order to examine patterns and associations with chemical exposures and childhood growth outcomes. The Generation R study is a unique prospective pregnancy cohort with rich existing information on prenatal non-persistent chemical exposures and long-term follow-up of children. Under this study, targeted and non-targeted metabolomics analysis of plasma samples will be collected and analyzed at early (<18 weeks gestation) and mid (18-25 weeks gestation) pregnancy as well as at delivery (cord blood plasma) among participants who have existing measures of prenatal chemical exposures as well as childhood follow-up to at least age 6.