Pregnancies in young adolescent mothers: a population-based study on 37 million births

Pregnancy in young adolescents is often understudied. The objective of our study was to evaluate the effect of young maternal age on adverse obstetrical and neonatal outcomes.

We conducted a population-based cohort study using the Center for Disease Control and Prevention's Linked Birth-Infant Death and Fetal Death data on all births in the US between 1995 and 2004. We excluded all births of gestational age under 24 weeks and those with reported congenital malformations or chromosomal abnormalities. Maternal age was obtained from the birth certificate and relative risks estimating its effect on obstetrical and neonatal outcomes were computed using unconditional logistic regression analysis.

37,504,230 births met study criteria of which 300,627 were in women aged <15 years with decreasing rates from 11/1,000 to 6/1,000 over a 10-year period. As compared to women 15 years and older, women <15 were more likely to be black and Hispanic, less likely to have adequate prenatal care, and more likely to not have had any prenatal care. In adjusted analysis, births to women <15 were more likely to be IUGR, born under 28, 32, and 37 weeks' gestation and to result in stillbirths and infant deaths. Prenatal care was protective against infant deaths in women < 15 years of age.

Although public health initiatives have been successful in decreasing rates of young adolescent pregnancies, these remain high risk pregnancies that may benefit from centers capable of ensuring adequate prenatal care.