In moderate-to-severely
iodine-deficient areas, controlled studies have demonstrated that iodine supplementation before or during early
pregnancy eliminates new cases of cretinism, increases birthweight, reduces rates of perinatal and infant mortality
and generally increases developmental scores in young children by 10–20%. Mild maternal iodine deficiency can
cause thyroid dysfunction but whether it impairs cognitive and/or neurologic function in the offspring remains
uncertain. Two meta-analyses have estimated that iodine-deficient populations experience a mean reduction in IQ
of 12–13.5 points. In nearly all regions affected by iodine deficiency, salt iodisation is the most cost-effective way of
delivering iodine and improving maternal and infant health