Impact of Maternal Iron Status on Neonatal Iron Status and Auditory Brainstem Response in the Newborn

Inclusion Criteria: * Adolescents (ages 11-18 y) and their newborns will be eligible to participate if the adolescent is carrying a singleton pregnancy, does not have any preexisting medical complications (such as HIV-infection, eating disorders, hemoglobinopathies, malabsorption diseases, steroid use, substance abuse history, or taking medications known to influence iron homeostasis). Exclusion Criteria: * Individuals with pregnancy induced hypertension or elevated diastolic blood pressure (\>110) will not be eligible to participate in the study. In addition, adolescents who have been previously treated for lead exposure, or those that have been identified as having elevated blood lead concentrations during childhood, will be excluded from the study. * Data from infants that experience perinatal asphyxia, pathologic neonatal hyperbilirubinemia, respiratory disease, antibiotic therapy (aminoglycosides), CNS infection, sepsis, congenital or middle or external ear lesions, craniofacial anomalies, chromosomal disorders, TORCH (toxoplasmosis, other infections, rubella, cytomegalovirus infection and herpes simplex infection) or those that were clinically unstable with the first 48 h post-delivery will be excluded from ABR studies. Infants born to mothers with positive drug abuse screens at delivery will also be excluded from further study (these screens are automatically run among this age group). Infants that are identified with hearing deficits at birth using the OAE screening will be excluded from the ABR measures.