Study Objective: To examine how parent-child relationships, parental control, and parental attitudes towards sex were related to pregnancy outcomes among adolescent mothers. Design: Prospective cohort study. Parental report of relationship satisfaction, disapproval of adolescent having sex, discussion around sexual health, and sexual communication attitudes, and adolescent report of relationship satisfaction, parental control, and parental disapproval of sex were examined as predictors of self-reported birth outcomes. Weighted multivariable linear regression models were run incorporating interactions by race. Setting: United States. Participants: 632 females who participated in Waves I and IV of the National Longitudinal Study of Adolescent Health (Add Health), a nationally-representative sample of students enrolled in grades 7-12 in 1994-95 and followed up in 2007-2008. Main Outcome Measures: Birthweight and gestational age. Results: For Black adolescents, better parent-child relationship was associated with higher birthweight (0.14 kg, P < .05) and gestational age (0.75 weeks, P < .01), while higher parental disapproval of having sex (adjusted beta 0.15 kg, P < .05) were associated with higher birthweight. For non-Black adolescents, a moderate amount of discussion of birth control was associated with higher birthweight (0.19 kg, P < .01 and lower child-perceived parental disapproval of having sex was associated with higher birthweight (0.08 kg, P < .05) and gestational age (0.37 weeks, P < .05). Higher parental control was associated with a reduced likelihood of smoking during pregnancy and a greater likelihood of early prenatal care. Conclusion: Parent-child relationships and attitudes about sex affect outcomes of pregnant adolescents.