title: Prenatal Exposure to PM10 and Preterm Birth between 1998 and 2000 in Seoul, Korea.
abstract: OBJECTIVE
  The exposure to particulate air pollution during the pregnancy has reported to result in adverse pregnancy outcome such as low birth weight, preterm birth, still birth, and intrauterine growth retardation (IUGR). We aim to assess whether prenatal exposure of particulate matter less than 10 (m in diameter (PM10) is associated with preterm birth in Seoul, South Korea.
  
  
  METHODS
  We included 382, 100 women who delivered a singleton at 25-42 weeks of gestation between 1998 and 2000. We calculated the average PM10 exposures for each trimester period and month of pregnancy, from the first to the ninth months, based on the birth date and gestational age. We used three different models to evaluate the effect of air pollution on preterm birth; the logistic regression model, the generalized additive logistic regression model, and the proportional hazard model.
  
  
  RESULTS
  The monthly analysis using logistic regression model suggested that the risks of preterm birth increase with PM10 exposure between the sixth and ninth months of pregnancy and the highest risk was observed in the seventh month (adjusted odds ratio=1.07, 95% CI=1.01- 1.14). We also found the similar results using generalized additive model. In the proportional hazard model, the adjusted odds ratio for preterm births due to PM10 exposure of third trimester was 1.04 (95% CI=0.96-1.13) and PM10 exposure between the seventh month and ninth months of pregnancy was associated with the preterm births.
  
  
  CONCLUSIONS
  We found that there were consistent results when we applied the three different models. These findings suggest that air pollution exposure during the third trimester pregnancy has an adverse effect on preterm birth in South Korea.
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Eun Hee
authors.initials: EH
authors.lastname: Ha
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Bo Eun
authors.initials: BE
authors.lastname: Lee
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Hye Sook
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Yun Sang
authors.initials: YS
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Ho
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Yun Chul
authors.initials: YC
authors.lastname: Hong
authors.affiliation: Department of Preventive Medicine, College of Medicine, Ewha Womans University, Korea. eunheeha@ewha.ac.kr.
authors.forename: Eun Ae
authors.initials: EA
authors.lastname: Park
keywords: Air pollution; PM10 (Particulate matter); Preterm birth