Residential exposure to outdoor air pollution during pregnancy and anthropometric measures at birth in a multicentre cohort in Spain

A growing body of research suggests that prenatal exposure to air pollution may be harmful to foetal development. In this study, the authors assessed the association between exposure to air pollution during pregnancy and anthropometric measures at birth in four areas within the Spanish Children’s Health and Environment (INMA) mother and child cohort study. Exposure to ambient N dioxide (NO2) and benzene was estimated for the residence of each woman (n ) 2,337) for each trimester and for the entire pregnancy. Outcomes included birth weight, length, and head circumference. The association between residential outdoor air pollution exposure and birth outcomes was assessed with linear regression models controlled for potential confounders. In addition, the authors performed sensitivity analyses for the subset of women who spent more time at home during pregnancy. Finally, the authors undertook a combined analysis with meta-analysis techniques. In the combined analysis, the authors observed an increase of 10 íg/m3 in NO2 exposure during pregnancy was associated with a decrease in birth length of -0.9 mm [95% confidence interval (CI), -1.8 to -0.1 mm]. For the subset of women who spent g 15 h/day at home, the association was stronger (-0.16 mm; 95% CI, -0.27 to -0.04). For this same subset of women, a reduction of 22 g in birth weight was associated with each 10-íg/m3 increase in NO2 exposure in the 2nd trimester (95% CI, -45.3 to 1.9). The authors observed no significant relation between benzene levels and birth outcomes. NO2 exposure was associated with reductions in both length and weight at birth. This association was clearer for the subset of women who spent more time at home.

Authors: Estarlich, Marisa; Ballester, Ferran; Aguilera, Inmaculada; Fernandez-Somoano, Ana; Lertxundi, Aitana; Llop, Sabrina; Freire, Carmen; Tardon, Adonina; Basterrechea, Mikel; Sunyer, Jordi; Iniguez, Carmen ;Full Source: Environmental Health Perspectives 2011, 119(9), 1333-1338 (Eng) ;