Gestational Blood Pressure Trajectories and 5-Year Postpartum Hypertension Risk in the MADRES Study

Blood pressure (BP) changes during pregnancy, but less is known about heterogeneous changing patterns within a population and long-term hypertension risk.

The purpose of this study was to identify distinct gestational systolic blood pressure (SBP) trajectories and examine their association with postpartum hypertension risk.

The MADRES (Maternal and Developmental Risks from Environmental and Social Stressors) (2015-present) cohort followed 854 pregnant individuals from early pregnancy to 5 years postpartum and collected information on demographics, lifestyle, and medical records, including BP at each prenatal visit. Latent class growth modeling was used to identify gestational SBP trajectories. Incident postpartum hypertension was identified from interviews and BP measurements. Cox modeling was used to assess the association of trajectory groups with the risk of hypertension at 2 to 5 years postpartum.

We identified 3 distinct gestational SBP trajectory groups. The majority (n = 685, 80.2%) had a "consistently low" trajectory over pregnancy. A "consistently elevated" trajectory group (n = 106, 12.4%) was characterized by modestly elevated SBP within a clinically normal range but lacked a midpregnancy dip. A "high-drop-high" trajectory group (n = 63, 7.4%) consisted of most cases of gestational hypertension or pre-eclampsia. Risk of hypertension in 5 years postpartum was 4.91 (95% CI: 2.01-12.0) fold higher in the "consistently elevated" group and 5.44 (95% CI: 1.89-15.7) fold higher in the "high-drop-high" group than the "consistently low" group, after adjusting for covariates.

Pregnant individuals with consistently elevated SBP yet within the subclinical range face longer-term risk of hypertension but may not be captured by standard prenatal clinical guidelines.