As part of the second National Health and Environment Plan, a national biomonitoring program was established between 2009 and 2010, with the InVS responsible for its operational management. This program includes, in particular, a perinatal component implemented within the ELFE cohort. The objective of this component is to describe the exposure of pregnant women and their children in utero to certain environmental pollutants suspected of playing an important role in the child’s future health. This assessment is based on the measurement of exposure biomarkers in biological samples collected at the time of delivery from a subsample of mothers included in the ELFE cohort (Vandentorren et al. 2009). The descriptive results presented concern lead, mercury, bisphenol A (BPA), pesticides, dioxins (PCDD), furans (PCDF), polychlorinated biphenyls (PCB), and brominated flame retardants (BFRs). An investigation into the determinants of exposure levels was conducted for lead and mercury.