Overt maternal hypothyroidism and/or iodine deficiency during pregnancy are linked to mental retardation in their offspring. Iodine deficiency may lead to maternal hypothyroxinemia, and even mild hypothyroidism in predisposed women. Indeed, thyroid hormones are of paramount importance for fetal brain development. During the first trimester of pregnancy, the only thyroid hormones available to the fetus are from maternal origin. Later in pregnancy, fetal thyroid progressively starts producing thyroid hormone, providing that maternal iodine status is adequate (≥200-250 mcg/day). It has been shown recently that mild maternal hypothyroidism may be responsible for discrete neuropsychological impairment in her child, implying a potential benefit for early screening and care during pregnancy. Furthermore, iodine deficiency is extremely common in our area (Brucker-Davis et al 2004). However, there is no official recommendation for screening and prevention, as for gestational diabetes for example.