Periconceptional neighborhood deprivation and risk of gestational and postpartum hypertensive disorders in a population-based cohort.

Hypertensive disorders during pregnancy and postpartum are major causes of maternal morbidity and mortality, yet associations with social determinants of health, including neighborhood deprivation, remain understudied. We examined the association of periconceptional neighborhood deprivation with the risk of gestational and postpartum hypertensive disorders in a population-based cohort of 281,621 pregnant individuals aged 15-44 years without chronic hypertension who delivered at Kaiser Permanente Northern California from 2011 to 2020. Neighborhood deprivation index (NDI) quartiles were assigned based on geocoded residential addresses before and in early pregnancy. Gestational hypertension and preeclampsia/eclampsia were identified from 20 gestational weeks through delivery, postpartum preeclampsia/eclampsia through six weeks postpartum, and postpartum hypertension through one year postpartum. Modified Poisson regression estimated adjusted relative risks (aRRs) across NDI quartiles. Overall, 16.2% versus 25.3% resided in the least (Q1) versus most deprived (Q4) neighborhoods. Greater neighborhood deprivation was associated with higher risk of gestational hypertension (Q4 vs Q1: aRR, 1.12 [1.07-1.17]), gestational preeclampsia/eclampsia (1.18 [1.12-1.24]), postpartum preeclampsia/eclampsia (1.30 [1.02-1.66]), and postpartum hypertension (1.67 [1.42-1.97]), with dose-response patterns across NDI quartiles. After adjusting for pre-pregnancy body mass index, associations attenuated, remaining significant only for postpartum hypertension (Q4 vs Q1: 1.30 [1.11-1.54]). Stratified analyses showed similar patterns among individuals with overweight/obesity but not those with underweight/healthy weight. These findings underscore the importance of considering neighborhood-level social determinants alongside individual-level risk factors when assessing risk of gestational and postpartum hypertensive disorders and the need for targeted interventions to reduce disparities and improve maternal health outcomes.