Abstract P166: First Trimester Plasma Per- and Polyfluoroalkyl Substance (PFAS) Concentrations and Blood Pressure Trajectories Throughout the Second and Third Trimesters of Pregnancy

Abstract

Introduction: Evidence suggests that PFAS exposures increase risk of hypertensive disorders of pregnancy. Prior studies did not examine blood pressure (BP) trajectories during pregnancy – an important outcome to consider since adverse health outcomes can occur without diagnosis of a hypertensive disorder. Hypothesis: We hypothesized that higher PFAS exposures in the 1 st trimester would be associated with higher BP trajectory and faster BP velocity in later stages of pregnancy. Methods: We collected plasma from 1,308 individuals to measure six circulating PFAS in early pregnancy (median: 9.4 weeks gestation). Systolic BP (SBP) and diastolic BP (DBP) measurements, recorded from 12 weeks gestation until delivery, were abstracted from outpatient medical records. We estimated the mean BP trajectory via growth curve analysis, then employed BKMR to examine PFAS exposures with parameters of the trajectory – adjusting for age, race/ethnicity, pre-pregnancy BMI, income, parity, alcohol intake, and physical activity. We evaluated effect modification by age and BMI. Results: We collected a median of 13 BP measurements (IQR: 11 – 14) per participant. BKMR single PFAS analyses showed higher concentrations of PFOS were associated with higher SBP and DBP trajectory from 12 weeks gestation to delivery (Figure 1A) as well as faster SBP velocity. Stratified analyses showed evidence of effect modification. PFOS was associated with higher SBP trajectory in those with a BMI < 25 kg/m 2 and higher DBP trajectory in those with a BMI ≥ 25 kg/m 2 (Figure 1B). In contrast, PFNA and PFHxS were associated with lower DBP trajectory for those with low BMI (Figure 1C). Lastly, exposure to lower quantiles of the PFAS mixture was associated with slower SBP velocity for those with low BMI. No associations were observed between PFAS and DBP velocity. Conclusions: Our findings suggest that select prenatal PFAS exposures may impact BP trajectories during pregnancy. Higher concentrations of PFOS are associated with higher BP trajectory and faster BP velocity. 1