Air pollution a hazard to pregnant women and their babies

Exposure to traffic-related air pollution may put pregnant women at risk of delivering preterm and the babies at risk of neonatal intensive care unit (NICU) admissions and low birthweight, among others, as reported in a study.

The study was retrospective and included singleton pregnancies in women residing in a metropolitan area in the southern US. Average nitrogen dioxide (NO2) concentrations were collected from the Environmental Protection Agency Air Quality System database. For women living within 10 miles of a monitoring station, average exposure to NO2 during their pregnancy was estimated by trimester.

Logistic regression models facilitated examination of the effect of pollutant exposure on gestational age at birth, indicated versus spontaneous delivery, and neonatal outcomes. Factors such as maternal age, self-reported race, parity, season of conception, diabetes, body mass index, registered Health Equity Index, and NO2 monitor region were included in the analysis as potential confounders.

Overall, 93,164 women delivered a singleton infant. Of these, 62,189 women had NO2 exposure data during the pregnancy from a nearby monitoring station.

Multivariable analysis showed that higher average NO2 exposure throughout pregnancy was associated with nearly twofold odds of preterm birth (adjusted odds ratio [aOR], 1.94, 95 percent confidence interval, 1.77–2.12) as well as increased likelihood of NICU admissions, low birthweight infants, neonatal respiratory diagnosis, neonatal respiratory support, and neonatal sepsis evaluation.

The observed association was consistently observed among nulliparous patients and was stronger for extremely preterm birth.