Endocrine disruptors are believed to have an even stronger effect during a child’s development, from pregnancy through the end of puberty. For fetuses, studies show an increase in developmental abnormalities, along with risks of premature birth, low birth weight, diabetes, or obesity. Given the lifelong significance of exposure during the first 1,000 days of life for the fetus, newborn, and young child up to age 2, Santé publique France is paying particular attention to this 1,000-day period.