Prenatal per- and polyfluoroalkyl substances and blood pressure trajectories in the New Hampshire Birth Cohort Study

Per- and polyfluoroalkyl substances (PFAS) have been associated with increased risk of hypertensive disorders of pregnancy, but whether PFAS influence blood pressure (BP) trajectories among normotensive pregnant women is unknown. We examined associations between PFAS mixtures and BP trajectories during pregnancy among normotensive women. PFAS concentrations, including perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), perfluorononanoate (PFNA), and perfluorodecanoate (PFDA), were measured in plasma collected at ∼28 gestational weeks among pregnant women enrolled in the New Hampshire Birth Cohort Study (2009-2018). Systolic BP (SBP) and diastolic BP (DBP) were abstracted from pregnancy medical records. We identified BP trajectories using latent class trajectory modeling and evaluated associations between PFAS mixtures and BP trajectories using probit Bayesian kernel machine regression and multinomial quantile g-computation. We used linear mixed models to examine individual PFAS and BP changes during the third trimester. Models were adjusted for sociodemographic, lifestyle, and reproductive factors, and gestational week of blood sample collection. During late pregnancy, plasma PFOS was associated with greater increases in SBP and PFHxS was associated with greater increases in DBP. Over the third trimester, each doubling in plasma PFOS was associated with 0.07 mmHg (95% CI: -0.01, 0.14) increase per week in SBP, and each doubling in plasma PFHxS was associated with 0.07 mmHg (95% CI: 0.02, 0.12) increase per week in DBP. Our study provides additional evidence suggesting that PFAS may adversely influence blood pressure even among normotensive women.