TPS 742: Adverse birth outcomes 1, Exhibition Hall, Ground floor, August 27, 2019, 3:00 PM - 4:30 PM Background/Aim: Evidence of the harmful effects of air pollution during pregnancy is mounting. Nevertheless, little is known about its potential effects on fetal mortality an increasingly important component of mortality in childhood, which is still insufficiently known, valued and studied as a public health problem, especially through approaches that integrate the biological and epidemiological dimensions. The proposed project aims to contribute to decreasing fetal mortality by increasing understanding of the complex network of causation related to fetal death, using a multidisciplinary approach, Methods: A case-control study with 415 cases (stillbirths) and 415 controls (randomly selected live births) in hospitals in the Metropolitan Region of São Paulo is underway. Mothers will be interviewed, hospital records abstracted, maternal and umbilical cord blood collected and placenta stored for investigation of serum and tissue markers of angiogenesis (vascular endothelial growth factor (VEGF), placental growth factor (PlGF), and fms-like tyrosine kinase receptor-1(sFlt-1)). In addition, DNA methylation and DNA-PAH adducts will be examined together with different measures of ambient and traffic-related air pollution. Non invasive autopsy will be conducted in all stillbirths, by imaging and histopathology guided by image as well as traditional autopsy. Results: Analysis will identify environmental, clinical and epidemiological risk factors for stillbirth, investigate their interrelationships and estimate the individual contributions to fetal mortality in this setting. Innovative statistical approaches for mapping the multicausal etiology of fetal deaths will be employed such as causal models and generalized spatial structural equation models with Bayesian inference. Conclusions: This research project aims to articulate the epidemiological and clinical frontiers and search for new knowledge to fill important gaps in our understanding of fetal mortality since previous studies have not included the environmental dimension. This will allow the design of effective prevention strategies.