TABLE 3.

Clinical evidence of the adverse impacts of MSE and maternal PM exposure.

Pollutant	Sample collecting time (gestation)	Adverse impact	References
Maternal smoking	9–14 weeks	High villous membrane and trophoblastic layer thicknesses	Jauniaux and Burton, 1992	Placenta
Maternal smoking	–	Smaller villous capillaries and high basement membrane thickness	Van der Velde et al., 1983
Maternal smoking	–	High villous membrane thickness	Burton et al., 1989
Maternal smoking	28 ± 1 weeks	Decreased uterine artery volume	Castro et al., 1993
Maternal smoking	1st trimester	More NK cells and macrophages, less regulatory T cells	Prins et al., 2012	Immune cells regulation
Maternal smoking	34th week	Lower Treg cell numbers	Herberth et al., 2014
Maternal smoking	After delivery	Attenuated innate immune responses	Noakes et al., 2006
Maternal smoking	During gestation	DNA methylation in cord blood cells	Joubert et al., 2016	Epigenetics
Maternal smoking	6–28 weeks infants	Lower antioxidant level and high oxidative stress level	Aycicek et al., 2005	Oxidative stress
Maternal smoking	3 months infants	Higher markers of oxidative stress	Noakes et al., 2007
PM10	1st and 2nd-trimester	Lower Pro- and anti-angiogenic factors and PlGF	van den Hooven et al., 2012	Placenta
PM2.5	Early/late gestation	Higher CD3 + and CD4 + lymphocytes and lower CD19 + and NK cell number during early gestation, which were opposite in the late gestation	Herr et al., 2010	Immune cells regulation
PM2.5	After delivery	Higher GSTP1 methylation	Lee A. G. et al., 2018	Epigenetics
PM2.5	During gestation	Higher 3-NTp levels (oxidative stress)	Saenen et al., 2016	Oxidative stress

GSTP1, Glutathione S-Transferase Pi 1; 3-NTp, 3-nitrotyrosine; MSE, maternal smoke exposure; NK cells, natural killing cells; PlGF, placental growth factor; PM, particulate matter; Treg cells, T regular cells.