The impact of air pollutants on spontaneous abortion: a case–control study in Tongchuan City.

Studies related to air pollutants and spontaneous abortion in urban northwestern China are scarce, and the main exposure windows of pollutants acting on pregnant women are unclear. Case-control study. Data were collected from pregnant women in Tongchuan City from 2018 to 2019. A total of 289 cases of spontaneous abortion and 1156 cases of full-term labor were included and analyzed using a case–control study. Logistic regression models were developed to explore the relationship between air pollutants and spontaneous abortion after Chi square analysis and Air pollutant description. O 3 (odds ratio [OR] = 1.028) is a risk factor for spontaneous abortion throughout pregnancy. PM 2.5 (OR = 1.015), PM 10 (OR = 1.010), SO 2 (OR = 1.026), and NO 2 (OR = 1.028) are risk factors for spontaneous abortion in the 30 days before the last menstrual period. PM 2.5 (OR = 1.015), PM 10 (OR = 1.013), SO 2 (OR = 1.036), and NO 2 (OR = 1.033) are risk factors for spontaneous abortion in the 30–60 days before the last menstrual period. PM 2.5 (OR = 1.028), PM 10 (OR = 1.013), SO 2 (OR = 1.035), and NO 2 (OR = 1.059) are risk factors for spontaneous abortion in the 60–90 days before the last menstrual period. Exposure to high levels of air pollutants may be a cause of increased risk of spontaneous abortion, especially in the first trimester of the last menstrual period. [ABSTRACT FROM AUTHOR]