Earlier maturation of pregnant black and white adolescents.

A survey was made of the menarcheal age and anthropometry of 1,844 lower income, nulliparous female patients receiving prenatal care. No differences were observed between black and white patients in height and maximum pregnant weight. A significantly earlier mean menarcheal age was observed in adolescents (12 to 16 years) compared with adults (17 to 31 years). Younger adolescents (12 to 14 years) of both races were taller and heavier (prepregnancy) than National Center for Health Statistics standards and had a significantly greater weight-for-height. Menarcheal age and body habitus were consistent with other reports that younger pregnant adolescents tend to be earlier maturers than older pregnant adolescents and adults. Compared with their age-group cohorts (13 to 31 years) in the two-decades-old Collaborative Perinatal Study of the National Institute of Neurological Communicative Disorders and Stroke, these female patients were larger and had greater pregnancy weight gains. These anthropometric findings may reflect the two decades of improvements in social assistance and prenatal care for lower income women.