The LIFECODES birth cohort study conducted at Brigham and Women’s Hospital (BWH) is an ongoing longitudinal study that aims to investigate contaminants associated with adverse pregnancy outcomes, isolate mechanisms underlying those associations, and identify predictors that can be used for prevention. Recruitment has been ongoing since 2006 and consequently the study population represents one of the nation’s largest pregnancy cohorts and specimen banks. The LIFECODES birth cohort is a unique resource for examining consumer product chemicals in relation to disorders of growth in pregnancy, and for investigating underlying mechanisms. With ongoing recruitment at BWH since 2006, the study population includes over 5,000 women enrolled at <15 weeks of gestation who contributed 3 urine and blood samples to the storage bank throughout pregnancy (median 10, 24, and 34 weeks), as well as 25,000 repeated ultrasounds (median 4 per woman). Within this cohort we have designed a case-cohort study to examine the associations between consumer product chemical exposures in pregnancy and disorders of fetal growth, including small for gestational age (<10th percentile, SGA) and large for gestational age (>90th percentile, LGA), and to investigate lipidomics profiles among participants as potential mediators of those associations. The purpose of this study is to examine associations between consumer product chemicals and disorders of fetal growth in the LIFECODES birth cohort.