In urban areas, the density of pollution sources combined with a high number of residents, constitute the optimal conditions for simultaneous exposure of pregnant women to many environmental pollutants. The occurrence of adverse pregnancy outcomes such as preterm delivery or fetal growth disorders could induce heavy consequences on the health of the mother and/or the newborn. What is the exposure level to noise or air pollution of pregnant women living in middle-sized cities? Is there a link between these exposures and prematurity, intra uterine growth disorders...? To answer these questions, the PreCEE research program has been conducted since 2012 in the region of Bourgogne-Franche-Comté. Nearly 11,000 deliveries that occurred between 2005 and 2009 at the Besançon or Dijon University Hospital were included. Delivery data, medical and obstetrical history, socio-economic conditions and living environment were collected from medical records. Road and railway traffics were the main noise and air pollution sources of these medium-sized cities. The mother?s address was used to assess environmental exposure to noise and air pollution. Environmental prediction models were used to assess outdoor pollutant exposures using MITHRA-SIG, COPERT IV and ADMS-Urban software. Air pollution, proximity to green spaces and noise were quantified at the living neighbourhood scale of each building. Furthermore, noise levels were also calculated in front of the entire façade and in front of the most exposed façade of each building. A deprivation index was calculated for the two cities. Logistic regression analyses were performed using classical and multilevel models. Many sensitivity analyses were conducted to explore the potential influence of the retained definition of exposure (pollutant, living area, time exposure window), adverse pregnancy outcomes (birth weight standards?) and missing data treatment. Technical, legal, and ethic parts of the project had also to be cautiously considered in the program.