The introduction to air pollution on pregnancy outcome (APPO) study: a multicenter cohort study.

The air pollution on pregnancy outcome, (APPO) study is a prospective hospital-based cohort study designed to investigate the maternal and fetal effects of particulate matter with an aerodynamic diameter <10 μm (PM10) and particulate matter with an aerodynamic diameter below 10 μm <2.5 μm (PM2.5) exposure. Specifically, approximately 1,200 pregnant women will be recruited for 3 years to collect data on exposure to fine dust, and the methods for measuring exposure to fine particles for each pregnant woman and estimating output will be established. This study aims to analyze the relationship between particulate matter and adverse pregnancy outcomes, identify related biomarkers, and develop management guidelines. We recruited early pregnant women without underlying diseases and collected biological samples using 5 mL of maternal venous blood and 15 mL of urine in each trimester of pregnancy; in addition, 5 mL of umbilical cord blood and 2×2×2 cm of placental tissue were collected after delivery. By applying PM10 and PM2.5 and time-activity patterns from the time-weighted average model, the individual predicted exposure to air pollution for the pregnant women was obtained. The APPO study can identify the degree of exposure to air pollution in pregnant women and use it as basic data for estimating individual exposure to particulate matter. The results of this APPO study will facilitate the development of health management strategies for pregnant women against air pollution.