Outside of pregnancy, proactive coping has been associated with both mental and physical well-being and with improved quality of life in chronic disease, but its effects in pregnancy are understudied. Our objective was to evaluate whether early pregnancy proactive coping was associated with adverse perinatal outcomes. This was a planned secondary analysis of nulliparous pregnant people recruited from a tertiary care center. Participants completed a validated assessment of proactive coping (Proactive Coping Scale) at 8-20 weeks and were followed longitudinally through delivery. Detailed pregnancy and delivery data were collected by trained research personnel. The primary outcome was a composite of adverse perinatal outcomes including unplanned cesarean delivery, gestational diabetes, and hypertensive disorders of pregnancy. Secondary analyses included individual perinatal composite components and a neonatal morbidity composite measure. Multivariate regression compared adverse perinatal outcomes by Proactive Coping Scale quartile, controlling for a priori confounders. Of the 281 parturients, the median Proactive Coping Scale score was 45.0 (range 25-55), and 47% experienced an adverse perinatal outcome. After adjusting for confounders, those in the lowest Proactive Coping Scale quartile had 2.2 times higher odds of experiencing an adverse perinatal outcome compared to those in the highest Proactive Coping Scale quartile. There were no differences in odds of the individual composite components or the adverse neonatal outcome. Lower early pregnancy proactive coping scores are associated with significant increase in adverse perinatal outcomes. Interventions that target improving proactive coping may be a novel mechanism for reducing perinatal morbidity.