Pre-pregnancy Dietary Vitamin A Intake May Alleviate the Adverse Birth Outcomes Associated with Prenatal Pollutant Exposure: Epidemiologic Cohort Study in Poland

Abstract

A cohort study assessed the relationship between dietary intake of vitamin A in 493 healthy mothers before and around conception and adverse birth outcomes associated with environmental toxicant exposures. The cohort, non-smoking women with singleton pregnancies, aged 18-35 years, gave birth at 34–43 weeks of gestation. The women were asked about their diets over one year preceding pregnancy. Measurements of PM_2.5 were carried out during the second trimester. Birth outcomes were adjusted for potential confounding factors, including gestational age. Standardized beta regression coefficients confirmed an inverse association between PM_2.5 and birth weight (beta = −172.4, P = 0.02), but the effect of vitamin A on birth weight was positive (beta = 176.05, P = 0.05), when the two were adjusted for each other. The negative effect of higher prenatal PM_2.5 exposures (above third tertile) on birth weight was significant in women below the third tertile of vitamin A intakes (beta = −185.1, P = 0.00), but notin women with higher intakes (beta = 38.6, P = 0.61). The negative effect of higher PM_2.5 exposure on length at birth was significant with lower vitamin A intakes (beta = −1.1, P = 0.00) but not with higher intakes (beta = −0.3, P = 0.56). Prepregnancy nutrition of mothers may modulate the harmful effects of prenatal exposures to pollutants on birth outcomes.

Keywords:

• air pollutants
• prenatal exposure
• prepregnancy vitamin A intake
• cohort study
• fetal growth