Iodine deficiency in pregnancy
Prior to the 1920's, iodine deficiency was one of the greatest public health problems in the U.S. At that time the federal government required iodine supplementation of salt and the problem was almost eliminated, but it is now beginning to show up again. The deficiency of iodine produced severe goiters in children in a region of the country − which resulted in the Northwest, the Great Lakes and Appalachian area to be known as the "goiter belt." The deficiency is still a major problem, affecting approximately two billion people worldwide. It is leading not only to goiter, but also developmental delays in children and severe hypothyroidism is women. Iodine is not made naturally by the human body, so it must be obtained either in food or by supplementation. Iodine is required by the body to make the thyroid hormones
Why is iodine deficiency being seen in the U.S. now?
Since the addition of iodine to salt, bread and dairy products in the U.S., public health official thought that the problem was solved. Now in the modern approach to diet, salt consumption is being reduced to attempt to reduce the risk of heart disease and hypertension. There is also a trend to reduce dairy consumption and bread in the diet to reduce weight gain. Seafood contains iodine, but pregnant women are now advised to reduce consumption of seafood due to the fear of mercury contamination.
What effects does iodine deficiency have on pregnancy?
The data shows that the following effects occur in women and their children when iodine deficiency is present:
- Maternal iodine deficiency can produce severe fetal hypothyroidism, leading to impaired development of the central nervous system − producing developmental problems and a condition called cretinism (a condition of stunted physical and mental growth). Recent studies have indicated that children born to women with iodine deficiency may have a risk of being born with lower IQs. Iodine deficiency has been determined to be the leading cause of preventable mental retardation in the world.
- Increased risk of infertility
- Increased risk of miscarriage
- Preterm birth
What measures should be taken for the near future?
Within the past few years, there have been several studies and organizations beginning to recommend that all pregnant women be tested for thyroid deficiency. Laboratory measurement of iodine has not gained favor at this time, but might need to be considered in the near future for all pregnant women. The World Health Organization now recommends that all pregnant women and breastfeeding women should receive 250 mcg of iodine as a supplement. In the U.S., the Institute of Medicine has recommended giving 220 mcg during pregnancy and 290 mcg during breastfeeding. A study reported in the New England Journal of Medicine showed few prescription prenatal vitamins contained iodine and the ones that had it listed as an ingredient was not bioavailable to the body. A study in South Australia led to recommendations by the Australian National Health and Medical Research Council to treat all pregnant women with 150 mcg of iodine. The American Thyroid Association, the Endocrine Society and the Teratology Society of America have recommended daily iodine supplements for any pregnant woman, breastfeeding woman or woman planning pregnancy.
If you have questions about this, talk to you physician.