Air Pollution Impact on Pregnancy Outcomes in Como, Italy.

OBJECTIVE

This retrospective observational study investigates the association between maternal exposure to air pollutants and pregnancy adverse outcomes in low urbanization areas.

METHODS

We used multivariate regression analysis to estimate, in the Como province (2005-2012), the effects of NO(x), NO2, SO2, O3, CO, and PM10 on low birth weight (LBW), babies small for gestational age (SGA), and preterm birth (PTB).

RESULTS

PTB was inversely associated with high (5.5 μg/m³) exposure to SO2 (adjusted odds ratio [aOR] = 0.74, 95% confidence interval [95% CI] = 0.58-0.95) and to CO (1.8 mg/m³, aOR = 0.84, CI = 0.72-0.99). PTB risk increased with second trimester exposure to NO(x) (118.3 μg/m³, aOR = 1.53, CI = 1.25-1.87), while LBW risk increased with third trimester PM10 (56.1 μg/m³, aOR = 1.44, CI = 1.03-2.02). SGA was inversely associated with third trimester NO(x) (115.8 μg/m³, aOR = 0.89, CI = 0.79-0.99).

CONCLUSIONS

Exposure to SO2 and CO seems to postpone delivery: a longer gestation could compensate for maternal hypoxemic-hypoxic damage.