Abstract Rationale Exposure to air pollution worsens blood pressure and cardiovascular health. Pregnancy may be a particularly sensitive window of exposure. Emerging evidence suggests that indoor air pollution exposures are significant; however, the effect of indoor pollutants on blood pressure over pregnancy is poorly described. To fill this gap, we leveraged an urban prospective pregnancy cohort study (CHIMES), to examine associations between repeated indoor air quality assessments and maternal blood pressure over pregnancy. Methods In CHIMES, we recruited pregnant persons from Elmhurst Hospital’s obstetrics clinic. Elmhurst Hospital is a public hospital in New York City, predominantly serving lower income, immigrant communities. We deployed stationary indoor air quality monitors in participants’ homes for 2-week periods, once in the second (HV1) and once in the third trimester (HV2), and measured fine particulate matter (PM2.5), carbon monoxide (CO) and nitrogen dioxide (NO2) every minute. We calculated mean exposure over each 2-week home visit as the exposure estimate for analyses. We performed electronic medical record review to collect resting maternal blood pressure measurements from routine obstetric appointments. The primary outcomes were the change in systolic and diastolic blood pressures (SBP, DBP) between the start of pregnancy and after completion of the second and third trimester home visits, respectively. We employed bivariate and multivariable linear mixed effects models to examine associations between exposure and blood pressure, adjusting for race, income, and secondhand smoke exposure. Results There were 63 participants included in the cohort; 50 completed HV1 and 39 completed HV2. An example of a participant’s pollutant exposure is shown in figure 1. Mean PM2.5 exposure (ug/m3) in HV1 was associated with significantly larger decreases in SBP (B = -0.325) and DBP (B = -0.248). Increased time (min) of PM 2.5 levels above 35 ug/m3 in HV1 was also associated with larger decreases in SBP (B = -0.002) and DBP (B = -0.001). Higher CO exposure (ppm) in HV1 was associated with larger decreases in DBP (B = -4.545), but not SBP. Higher mean NO2 exposure (ppm) in HV1 was also associated with larger decreases in DBP only (B = -369.712). There were no significant differences detected in HV2. Conclusions Increased indoor pollutant exposure was associated with larger decreases in blood pressure over the course of pregnancy. These findings stand in contrast to existing literature. More research is needed to determine if specific pollutants or patient characteristics modulate the effects on blood pressure to explain these differences. This abstract is funded by: American Lung Association
Gross et al. (2026) studied this question.