Objective <p>To investigate whether perinatal stressors (gestational weight gain, maternal age, marital status, and maternal body composition) exert a direct effect on sleep quality in adolescence; whether these effects are mediated by socioeconomic factors, lifestyle, and comorbidities; and whether depression, screen time, and physical activity have a direct effect on adolescents’ sleep quality.</p> Methods <p>Longitudinal cohort study was nested within a Brazilian birth cohort including 527 participants aged 18–19 years. Structural equation modeling was used to examine pathways linking perinatal stressors to sleep quality. Sleep quality was assessed using the Pittsburgh Sleep Quality Index. Explanatory variables included perinatal maternal characteristics, socioeconomic factors, lifestyle, and adolescent comorbidities.</p> Results <p>Among perinatal stressors, only maternal marital status at birth showed a direct effect on adolescents’ sleep quality (coef = 0.14; <i>p</i> = 0.027). Depression (coef = 0.38; <i>p</i> = 0.001) and asthma (coef = 0.19; <i>p</i> = 0.030) were directly associated with poorer sleep quality. No evidence of mediation by socioeconomic status, lifestyle, or comorbidities was found. Other perinatal stressors, screen time, and physical activity were not associated with sleep quality.</p> Conclusions <p>Maternal marital instability during the perinatal period may have lasting consequences for adolescents’ sleep quality, possibly through direct neurobiological mechanisms. Depression and asthma emerged as predictors of poor sleep quality, underscoring the need for integrated early screening and intervention strategies.</p> Brief summary Current knowledge/study rationale <p>Perinatal adversities can dysregulate the hypothalamic–pituitary–adrenal (HPA) axis and circadian brain structures, leading to alterations in sleep patterns. However, the long-term consequences of perinatal stressors on sleep quality remain poorly understood, particularly during adolescence. The scarcity of longitudinal data limits our understanding of the neurobiological mechanisms underlying these associations.</p> Study impact <p>This study identifies maternal marital status at birth as a predictor of sleep quality in adolescence, suggesting long-term neurobiological effects. The findings underscore the importance of maternal support programs and early, integrated interventions addressing mental health, respiratory conditions, and sleep disorders—approaches that may yield lasting benefits for adolescents’ cognitive, emotional, and physical development.</p>