Conclusions
Compared to normotensive pregnancies, pregnancies complicated by chronic hypertension are associated with increased risk for perinatal mortality, including stillbirth and neonatal death. A large driver of this risk was preterm delivery, but there was also a substantial increased risk of perinatal mortality at term and late term gestations. The results of this study suggest the best strategies to reduce the risk of perinatal mortality include planned, early term deliveries and targeting modifiable risk factors for chronic hypertension, such as advanced maternal age and obesity, that may impact the prevalence of chronic hypertension.