Cohort profile: The Camden Study - a pregnancy cohort study of pregnancy complications and birth outcomes in Camden, New Jersey, USA.

Background: Pregnancy is a unique stage of the life course characterized by trade-offs between the nutritional, immune, and metabolic needs of the mother and fetus. The Camden Study was originally initiated to examine nutritional status, growth, and birth outcomes in adolescent pregnancies and expanded to study dietary and molecular predictors of pregnancy complications and birth outcomes in young women. Methods: From 1985-2006, 4765 pregnant participants aged 12 years and older were recruited from Camden, NJ, one of the poorest cities in the U.S. The cohort reflects a population under-represented in perinatal cohort studies (45% Hispanic, 38% non-Hispanic Black, 17% White participants; 98% using Medicaid in pregnancy). Study visits, including questionnaires, dietary assessments, and biospecimen collection, occurred in early and late pregnancy as well as at delivery. Medical records were abstracted, and a subset of mothers and infants participated in a six-week postpartum visit. Results: Over the last five decades, the Camden Study has provided data toward the publication of numerous peer-reviewed papers. Results show that adolescent linear growth in pregnancy is associated with smaller birth size, possibly due to impaired hemodynamics. In the context of preterm birth and other perinatal outcomes, analyses of nutritional data have demonstrated the importance of micronutrients (e.g., folate, iron, zinc), as well as glucose/insulin dynamics and prenatal supplement use. More recent analyses have begun to unpack the biochemical pathways in pregnancy that may be shaped by race as an indicator for systemic racism. Conclusions: The Camden Study data and biorepositories are well-positioned to support future research aimed at better understanding perinatal health in under-represented women and infants. Linkages to subsequent health and administrative records and the potential for recontacting participants over 18-39 years after initial participation may provide key insights into the trajectories of maternal and child health across the life course.