Effects of Air Pollution in Amniotic Fluid Index in the Third Trimester of Pregnancy

Objective: To evaluate the role of exposure to urban air pollution on regulation of fetal amniotic fluid volume. Methods: The sample was selected in West region of the city of Sao Paulo and integrates a cohort study in pregnant women. Individual exposure to air pollution was measured by passive tubes for measurements of NO2. These passive tubes were used by the mothers during 10 days and sampling campaigns were conducted at the first, second and third trimesters of gestation. Assessment of amniotic fluid volume in singleton pregnancies was performed by ultrasonography examination at the third trimester by the technique of amniotic fluid index (AFI), and expressed in cm. A binary logistic model was computed using as the dependent variable: amniotic fluid index ( 15.685, the highest quartile of the sample) and the following independent variables: NO2 in the first trimester, NO2 in the second trimester, NO2 in the third trimester, smoking and gestational age at ultr...