PurposeTo provide a comprehensive assessment of maternal and neonatal complications associated with teen pregnancies in the United States. MethodsRetrospective analysis of the Centers for Disease Control and Prevention natality live births database (2016-2019). Singleton births to women younger than 35 years from the following racial/ethnic groups were included: non-Hispanic White, non-Hispanic Black, non-Hispanic Asian, and Hispanic. The risks of various complications were compared between teen patients (<20 years old) and nonteen patients (20–35 years old) using Pearson's chi-square test with the Bonferroni correction. Multivariate logistic regressions were used to adjust outcomes for potential confounders, including body mass index, race/ethnicity, payment method, prenatal care, parity, and the presence of chronic comorbidities. ResultsTeen pregnancies comprised approximately 6% of the study population (661,062 of 11,038,489). Teen pregnancies were associated with increased odds of several maternal complications, such as hypertensive disorders of pregnancy, eclampsia, preterm birth, blood transfusion, and chlamydial and gonorrheal infections. Teen pregnancies were also associated with increased odds of several neonatal complications, including congenital birth defects, low 5-minute Apgar score, suspected neonatal sepsis, and assisted ventilation. Conversely, teen pregnancies were associated with decreased odds of gestational diabetes, unplanned hysterectomy, macrosomia, low birth weight, and neonatal intensive care unit admission. DiscussionTeen pregnancies in the United States are associated with increased risks of multiple adverse outcomes. This information should inform clinicians and policy makers about the unique risks of this highly vulnerable patient population and provide further knowledge for the important efforts to reduce teen birth rates in the United States.