Thesis Abstract

Maternal exposure to air pollution has been a topic of growing concern due to its potential impact on birth outcomes. This research project aimed to investigate the relationship between maternal exposure to air pollution and various birth outcomes including preterm birth, low birth weight, and small for gestational age infants. The study utilized a systematic review and meta-analysis approach to synthesize existing literature on the subject. A comprehensive search strategy was employed to identify relevant studies published in scientific databases. Studies that met the inclusion criteria were selected for data extraction and analysis. The meta-analysis was conducted to quantitatively assess the association between maternal exposure to air pollution and adverse birth outcomes. The results of the meta-analysis revealed a significant association between maternal exposure to air pollution and an increased risk of adverse birth outcomes. Specifically, higher levels of air pollutants such as particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2) were found to be positively associated with an elevated risk of preterm birth, low birth weight, and small for gestational age infants. The findings were consistent across different geographic regions and study populations. Subgroup analyses were conducted to explore potential sources of heterogeneity and to examine the impact of different study characteristics on the overall results. Sensitivity analyses were also performed to assess the robustness of the findings. Overall, the results remained stable and statistically significant, indicating a strong and consistent association between maternal exposure to air pollution and adverse birth outcomes. The implications of these findings are significant for public health policy and clinical practice. Efforts to reduce air pollution levels, particularly in urban areas where pregnant women are more likely to be exposed, may help improve birth outcomes and maternal health. Healthcare providers should also consider the potential impact of air pollution on pregnancy outcomes when counseling pregnant women. In conclusion, this research provides compelling evidence of the adverse effects of maternal exposure to air pollution on birth outcomes. Further research is needed to elucidate the underlying mechanisms and to develop effective interventions to mitigate the impact of air pollution on maternal and child health.

Thesis Overview

The knowledge about air pollution effects on birth weight, prematurity, and small for gestational age (SGA) in low-exposure areas is insufficient.Maternal Exposure

OBJECTIVES:

The aim of this birth cohort study was to investigate whether low-level exposure to air pollution was associated with prematurity and fetal growth and whether there are sex-specific effects.Maternal Exposure

METHOD:

We combined high-quality registry information on 81,110 births with individually modeled exposure data at residence for nitrogen oxides (NO(x)) and proximity to roads with differing traffic density. The data were analyzed by logistic and linear regression with and without potential confounders.Maternal Exposure

RESULTS: We observed an increased risk for babies being SGA when we compared highest and lowest NO(x) quartiles, adjusting for maternal age, smoking, sex, and year of birth. After additional adjustment for maternal country of origin and parity (which were highly intercorrelated), the increase was no longer statistically significant. However, in subgroup analyses when we compared highest and lowest NO(x) quartiles we still observed an increased risk for SGA for girls [odds ratio (OR)=1.12; 95% confidence interval (CI), 1.01-1.24); we also observed increased risk among mothers who had not changed residency during pregnancy (OR=1.09; 95% CI, 1.01-1.18). The confounders with the greatest impact on SGA were parity and country of origin. Concerning prematurity, the prevalence was lower in the three higher NO(x) exposure quartiles compared with the lowest category.Maternal Exposure