Mother with severe Iodine deficiency are more likely to have neonates with further poor mental development . In order to select population which could benefit from iodine supplementation, ioduria has been tested but cannot be routinely practised. Strong background data suggest that iodine status could be antenatally correlated with foetal thyroid volume. The aim of that study is to examine correlation between these two parameter in a population of 130 healthy pregnant women.