Maternal Specimens (M1, M2, M3): Maternal blood, urine, and placental tissue are collected.
Child Specimens (M3, CV1-CV4): Cord blood and placental tissue collected are collected at delivery. If cord blood was not collected at delivery, a buccal swab is collected from the child at a later visit. A small hair sample is collected from the child at each clinic visit. A blood sample and buccal swab are taken at the 4 year clinic visit.