Household air pollution and angiogenic factors in pregnant Nigerian women: A randomized controlled ethanol cookstove intervention

Abstract

Background: Maternal exposure to ambient air pollution affects placental growth markers.

Objectives: Investigate impact of household air pollution (HAP) on placental growth markers.

Methods: Two groups of pregnant women were identified: firewood/kerosene stove-users (A, n=33) and bioethanol stove-users (B, n=44) that participated in a randomized control trial in Ibadan, Nigeria. A third group of non-smoking and presumed liquefied petroleum gas-using Chicago women (C, n=19) were included in this exploratory pilot to assess for possible differences between similar racial groups. Levels of placental growth factor (PlGF) and soluble fms-like tyrosine kinase 1 (sFlt-1) were measured in maternal and cord plasma using ELISA.

Results: Maternal and cord blood sFlt-1 and PlGF did not differ significantly between women of groups A and B. Nevertheless, both groups differed significantly from the Chicago group in that group A women had lower maternal sFlt-1 (1372.50 vs. 3194.19) but higher PlGF (1607.87 vs. 442.80), and higher cord blood sFlt-1 (2925.02 vs. 107.53) and PlGF (223.68 vs. 6.92), all p≤0.001. Group B showed similar trends (all p≤0.002). Maternal PlGF levels were positively correlated to minutes of HAP exposure when PM_2.5 concentration was above 100μg/m³ in Nigerian women.

Conclusions: Maternal levels of PlGF and cord blood levels of sFlt-1 and PlGF in Nigerian women with varying HAP exposures were significantly higher than Chicago-based women who had no presumed HAP exposure. It suggests that in-utero exposure to HAP influenced levels of angiogenic factors involved in normal placentation and growth and could represent compensation for pollutants exposure to preserve fetal viability.

Keywords: Cord blood; Household air pollution; Nigeria; Placental growth factor; Pregnant women; sFlt-1.