Meta-analysis of studies testing the association between air pollution and live birth rates in women undergoing...

Amidst a proliferation of research on air pollutants and negative pregnancy outcomes, uncertainty lingers regarding their impact on live birth rates in women receiving assisted reproductive technology (ART). This meta-analysis aims to clarify this vital issue. We searched EMBASE, PubMed, and Web of Science databases, targeting articles published prior to 2023 August 2. We pooled relative risks (RRs) and their corresponding 95% confidence intervals (95%CIs) across all included studies to assess the relationship between exposure to air pollutants and live birth rates. From an initial 5,785 citations, we identified five eligible papers with a total sample size of approximately 282,000 participants. In the year prior to oocyte retrieval, for every 10 μg/m³ increase in fine particulate matter (PM_2.5) (RR: 0.94, 95%CI: 0.92-0.97) and coarse particulate matter (PM₁₀) (RR: 0.95, 95%CI: 0.92-0.97), the probability of live birth decreased by 6% and 5%, respectively. For every additional ppb increase in nitrogen dioxide (NO₂) (RR: 0.92, 95%CI: 0.87-0.98), the likelihood of live birth decreased by 8%. This meta-analysis demonstrates adverse associations between air pollution and live birth rates in women undergoing ART. These findings highlight further elucidate the observed associations, as well as to explore potential mechanisms and implications for reproductive health.