Iodine deficiency during pregnancy

During pregnancy and lactation the need for iodine is increased because the mother’s body has to supply not only itself but also the unborn or newborn with sufficient iodine. In pregnancy and lactation it is more difficult to take up sufficient iodine through food because of the increased iodine requirement. Pregnant and nursing mothers should therefore take 150 to 200 micrograms of iodine daily.

Already in the 12th week of pregnancy, the thyroid gland of the unborn child starts producing hormones. The thyroid hormones are absolutely necessary for physical and mental maturation. An iodine deficiency in the newborn causes disorders of the thyroid gland function.

The consequence may be Icterus neonatorum prolongatus, which means that the jaundice of the newborn child will persist longer than in children without iodine deficiency. Newborns with iodine deficiency are also lazy to drink, suffer more often from constipation and move less. It is possible that the reflexes of the muscles, e.g. the patellar tendon reflex, are weaker.

Umbilical hernias are more common in disturbed thyroid function due to iodine deficiency than in newborns with a fully functional thyroid gland. The iodine deficiency during pregnancy causes hypothyroidism, in the further course of the disease hearing loss, speech disorder, growth retardation and mental retardation develop. Mental retardation is so pronounced after only three weeks that the distance to normally developed children can no longer be caught up with.

For this reason, every newborn in Germany is tested for an underfunction of the thyroid gland (e.g. due to iodine deficiency). A goiter or struma describes an enlargement of the thyroid gland and is the most common endocrine disorder. In iodine deficient areas, up to 30% of adults have iodine deficient goiter.

Goiter can occur in various thyroid diseases, iodine deficiency being one of them. Iodine deficiency activates growth factors in the thyroid gland, the cells of the thyroid gland divide, more cells are formed and swelling of the thyroid gland occurs. As a result of iodine deficiency, less thyroid hormones are produced.

A deficiency of thyroid hormones leads to increased growth of thyroid cells through the release of TSH (thyroid stimulating hormone, see above), so the individual cell becomes larger. Both mechanisms contribute to the formation of the goiter. A goiter can cause a feeling of pressure or lumps in the throat.

A small goiter usually causes no problems, whereas a large goiter can displace the trachea and obstruct breathing. It is also possible that the cartilage of the windpipe is damaged and broken down (tracheomalacia). Over time, the enlarged thyroid gland undergoes nodular remodelling, which can lead to the development of an autonomous thyroid gland.

An autonomous node produces thyroid hormones without submitting to the body’s normal regulatory circuit. A large and knotty goiter should be operated on, as well as a goiter that obstructs the other organs in the neck or a goiter that reappears after surgery. A goiter, which is caused by iodine deficiency, is in many cases symmetrical and soft. The thyroid gland can maintain a good metabolic position by forming a goiter. An enlarged thyroid gland, which however produces a normal amount of hormones, is called euthyroid goiter.