This survey article connects physiology of anatomical and functional development of thyroid gland with maternal iodine supplementation and maternal disorders of thyroid gland. The fetus is fully dependent on maternal thyroid hormones until week 14 to 16 of gestation.
The production of its own thyroid hormones gradually increases in the third trimester. Maternal iodine supplementation is essential for the developing fetus in the whole course of gestation.
If the mother suffers from thyroid disease or iodine deficiency, the child's neurocognitive functions are more affected despite being treated for congenital hypothyroidism in time.