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When Caryn was five months pregnant she was told by her doctor she had an iodine deficiency. Initially she wasn’t unduly worried. She had worked hard to stay fit and healthy during her pregnancy and was taking some supplements. How could it be serious? Tests had shown her to be mildly to moderately iodine deficient, and she was not alone. Most recently, there has been a re-emergence of iodine deficiency in Australia and New Zealand, with around 50% of the population considered to have inadequate iodine intakes. Why is this deficiency such a huge cause for concern? And how can it be treated?
During pregnancy, thyroid hormone requirements are increased by about 50% over pre-pregnancy levels. A lack of iodine during pregnancy can have a significant impact on the brain development of babies both in-utero and after birth. In addition, young children can experience developmental, learning and hearing problems if there is an iodine deficiency. If the deficiency is severe the child may develop a condition called iodine-deficiency disorder (IDD). IDD is a major contributing cause for preventable mental retardation and brain damage in children. Once the damage is done, it is irreversible.
Iodine is used by the thyroid gland to make thyroid hormone – one of the important hormones that drives our metabolism. With insufficient iodine, the mother (or the infant) can’t make enough thyroid hormone to supply the needs of the growing and developing brain. If hypothyroidism, where the thyroid gland is not working effectively, develops early in pregnancy, there is significant risk of miscarriage, premature labour and neurological damage to the fetus.
Given that many pregnant women in Australia and New Zealand have an iodine deficiency, women need to be very pro-active in ensuring they are getting enough iodine.
So how can women prevent this condition? Firstly you cannot do it by diet alone. You would need to eat large quantities of food in order to do so. You need an extra 100 – 200 ug of iodine a day during pregnancy. The Food Standards Australia and New Zealand (FSANZ) have implemented the mandatory use of iodised salt in bread in an effort to help increase levels of iodine in food, but this fortification is insufficient.