Racial/Ethnic Differences in Correlates of Spontaneous and Medically-Indicated Late Preterm Births among Adolescents.

STUDY OBJECTIVE: To investigate the racial/ethnic differences in the correlates of spontaneous and medically-indicated late preterm birth (LPTB), defined as deliveries between 34 0/7 and 36 6/7 weeks gestation, among US adolescents.

DESIGN: Population-based, retrospective cohort study.

SETTING: Births in the United States to adolescents in 2012.

PARTICIPANTS: Adolescents (younger than 20 years; n = 171,573) who delivered nonanomalous singleton first births between 34 and 44 weeks of gestation.

INTERVENTIONS AND MAIN OUTCOME MEASURES: Bivariate and multivariable logistic regression were used to evaluate the associations between maternal risk factors and spontaneous and medically-indicated LPTB, stratified according to maternal race/ethnicity.

RESULTS: Risk factors for spontaneous LPTB included single marital status among Asian adolescents; no insurance coverage among whites, Asian, and Hispanic adolescents; inadequate prenatal care among all racial/ethnic groups except American Indian, and adequate plus prenatal care among all races/ethnicities; prenatal smoking among whites and black adolescents; insufficient gestational weight gain among all racial/ethnic groups except American Indian; and prepregnancy underweight among white, black, and Hispanic adolescents. Risk factors for medically-indicated LPTB included inadequate prenatal care among white, black, and Hispanic adolescents, and adequate plus prenatal care among all racial/ethnic groups except Asian; insufficient gestational weight gain among white, black, and Hispanic adolescents; and prepregnancy overweight and obesity among white, black, and Hispanic adolescents.

CONCLUSION: Our results show racial/ethnic differences in the correlates of spontaneous and medically-indicated LPTB among US adolescents and support the need for risk-specific interventions among different racial/ethnic groups.