Iodine Deficiency in Pregnant Women

Iodine is essential to a woman during pregnancy to maintain normal metabolism, as well as to supply sufficient thyroid hormones to the foetus.

An insufficient supply of thyroid hormones to the developing brain of the foetus can result in congenital anomalies and intellectual impairment.

The study, conducted by health professionals in Gosford and Sydney, examined the iodine status of pregnant women and their newborns in the Central Coast area of New South Wales.

The biggest of its kind in Australia, the study looked at the correlation between two indicators of iodine status; maternal urinary iodine concentration (UIC) and newborn whole-blood thyroid stimulating hormone (TSH).

"Few studies have examined the possible correlation between maternal UIC and new-born TSH level," said study co-author Cheryl Travers, Manager of the Central Coast Public Health Unit.

Although the women surveyed were mildly iodine deficient, TSH levels in their newborns were mostly within acceptable limits.

However, Ms Travers cautioned that the finding should not encourage expectant mothers to become complacent about maintaining adequate iodine intake.

"The median UIC in women giving birth at both public and private hospitals was well below the level of optimal iodine nutrition during pregnancy," Ms Travers said.

"Despite the TSH values being within the normal range, it is clear that pregnant women are not getting adequate dietary iodine."

Iodine deficiency may be due to a lack of education about nutrition during pregnancy or insufficient planning for pregnancy, Ms Travers said.

"We support the call to raise awareness of the need for pregnant and lactating women to increase their iodine intake," she added.

The Medical Journal of Australia is a publication of the Australian Medical Association.