Childhood pregnancy (10-14 years old) and risk of stillbirth in singletons and twins

ObjectiveTo clarify the association between childhood pregnancy and risk of stillbirth.Study designWe analyzed singleton and twin pregnancies that occurred in children (10-14 years old) in the United States from 1989 to 2000. We estimated the absolute and relative risks of stillbirth by using 15- to19-year-old and 20- to 24-year-old mothers as comparison groups.ResultsThe analysis involved 17.8 million singletons and 337,904 individual twins. The rate of stillbirth was highest in pediatric mothers for both singletons (12.8/1000) and twins (56/1000) compared with adolescent (6.8/1000 in singletons and 29/1000 in twins) and mature (5.5/1000 in singletons and 20/1000 in twins) mothers. After adjusting for confounding characteristics, pediatric mothers continued to exhibit significantly elevated risk for stillbirth in both singletons (odds ratio, 1.57; 95%CI, 1.49-1.66) and twins (odds ratio, 1.97; 95%CI, 1.42-2.73). Preterm birth rather than small size for gestational age was revealed by means of sequential modeling to account for the excess risk of stillbirth observed in pediatric gravidas.ConclusionPregnancy in childhood is a risk factor for stillbirth; shortened gestation rather than reduction in fetal growth is the mediating pathway.