Association of dynamic blood pressure trajectory during pregnancy with adverse birth outcomes: a large prospective...

This study investigated the associations between dynamic blood pressure (BP) trajectories during pregnancy and adverse birth outcomes using data from the China-US Collaborative Project on Neural Tube Defect Prevention. Among 281,224 pregnant women (mean age 25.07 ± 3.57 years), group-based trajectory modeling (GBTM) identified three distinct systolic (SBP) and diastolic (DBP) BP patterns: "Low-stable", "Fast-increasing", and "High-stable". Compared to the Low-stable SBP group, women with Fast-increasing or High-stable SBP trajectories had significantly elevated risks of adverse outcomes, including an 16% higher risk of preterm birth (adjusted OR = 1.16, 95% CI:1.09-1.23) and 37% increased risk of low birth weight (LBW) (aOR=1.37,1.27-1.49) in the High-stable group. For DBP, the Fast-increasing trajectory showed the strongest associations, with a 19% higher preterm birth risk (aOR=1.19,1.11-1.26) and 63% increased LBW risk (aOR=1.63,1.51-1.76). Each 10 mmHg rise in SBP and DBP from mid-to-late pregnancy was independently linked to higher risks of preterm birth (SBP: aOR=1.10,1.06-1.12; DBP: aOR=1.16,1.13-1.20) and low birth weight (SBP: aOR=1.12,1.09-1.14; DBP: aOR=1.22,1.18-1.26). These findings highlight that dynamic BP changes during pregnancy are robust predictors of adverse birth outcomes, underscoring the importance of continuous BP monitoring for early risk identification and intervention.