Estimation of pregnancy losses attributable to exposure to ambient fine particles in south Asia: an epidemiological case-control study
Maternal exposure to ambient particulate matter (PM2·5) is associated with pregnancy loss (ie, stillbirth and miscarriage). 
South Asia has the highest burden of pregnancy loss globally and is one of the most PM2·5 polluted regions in the world. However, knowledge of the relevant exposure–response function for mothers is insufficient.