NPC to assess effects of maternal iodine nutrition and thyroid status on children cognitive development.

Maternal iodine nutrition and thyroid status may influence neurocognitive development in children. This study investigated the effects on the intelligence quotient (IQ) of children born to mothers with different levels of iodine supplementation, with or without the administration of levothyroxine (LT4), prior to and during pregnancy. From a methodological point of view, we used the Non Parametric Combination test or NPC test, based on permutation solution. It was chosen for the several optimal properties of which it is characterized, that make it very flexible and widely applicable in many fields; in particular, it allows stratified analyses and represents an effective solution for problems concerning the testing of multidimensional hypotheses, that are difficult to face in a parametric context.