Background: Household air pollution is a major contributor to cardiovascular disease burden in women in Sub-Saharan Africa. However, little is known about exposures during pregnancy or the effect of clean cooking interventions on postpartum blood pressure trajectories. Methods: The Ghana Randomized Air Pollution and Health Study (GRAPHS) randomized 1414 non-smoking women in the first and second trimesters to liquefied petroleum gas (LPG) or improved biomass stoves – vs control (traditional three-stone open fire). Personal exposure to carbon monoxide was measured at four prenatal timepoints and three times over the first postpartum year. Participants were prospectively followed with annual resting BP measurements at 2, 4, 5, 6, 7, and 8 years postpartum. We employed linear mixed effects models to determine effect of GRAPHS interventions on postpartum BP, and to examine associations between prenatal and postnatal CO and postpartum BP. Results: LPG intervention was associated with 3.54mmHg (95% CI -5.55, -1.53) lower change in systolic BP from enrolment through 8 years postpartum, and 2.27mmHg (95% CI -3.61, -0.93) lower change in diastolic BP from enrolment through 8 years postpartum, as compared to control. In exposure-response analysis, average prenatal CO was positively associated with change in systolic BP from enrolment (β=0.71mmHg, 95% CI 0.08, 1.30, per doubling of CO) Conclusions: LPG cookstove intervention initiated in early pregnancy and maintained through the first postpartum year was associated with lower systolic and diastolic BP trajectories through 8 years postpartum. These findings support the need to integrate clean cooking solutions into existing antenatal care packages.

The authors have declared no competing interest.

Clinical Trial Registration Number: NCT01335490

GRAPHS was supported by the National Institute of Environmental Health Sciences (NIEHS) Grants R01 ES019547, R01 ES026991, R01ES034433, P30 ES009089, and P30 ES023515, Fogarty Institute R21 TW010957, NIH Shared Instrument Program S10OD016219, Thrasher Research Fund, and the Clean Cooking Alliance. AGL was additionally supported by the National Heart, Lung and Blood Institute K23 HL135349. The authors and their institutions declare that they did not receive payments from third parties for any aspect of the work presented in this manuscript.

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