Maternal residential proximity to major roads in north west England and adverse pregnancy outcomes.

OBJECTIVE: To investigate the effects of maternal residential proximity to major roads on adverse pregnancy outcomes. METHODS: Major road networks in North West England were linked to the maternal residence of 190,909 births (2004 to 2008). Distance between the residence and the nearest major road was calculated and dichotomized at 200 m. Logistic regression analyses were performed to investigate the association between distance to the major road with small for gestational age, low birth weight, and preterm birth. Analyses were adjusted for maternal age, ethnicity, socioeconomic status, parity, birth season, smoking, and body mass index. RESULTS: No significant associations were observed between preterm birth (odds ratio [OR] = 1.04; 95% confidence interval [CI] = 0.98 to 1.11), low birth weight (OR = 0.99; 95% CI = 0.93 to 1.05) and small for gestational age (OR = 1.00; 95% CI = 0.95 to 1.06) and living less than 200 m from a major road. CONCLUSIONS: These results, from a study with high statistical power, suggest that living less than 200 m from a major road per se does not pose any great risk of an adverse perinatal outcome. Nevertheless, it may be limited to this geographic location. Further work is needed to quantify individual pollutant effects in pregnancy.