Iodine intake in pregnancy - the effects of the Australia wide public health campaign in regional West Victoria.

Abstract

Iodine, as a building block for thyroid hormones, is vital for the normal development and function of the brain and organ systems. Iodine deficiency is a global health problem, declared by WHO to be the most common preventable cause of intellectual impairment. Dietary iodine intake is of particular importance in pregnant and breastfeeding women given the neurodevelopmental vulnerability of the fetus and child to age three. Despite this, data on the prevalence of iodine deficiency in pregnancy is lacking from most countries. In October 2009 the Mandatory Iodine Fortification for Australia programme was initiated to address countrywide iodine deficiency. Additionally national public health campaigns recommended iodine supplementation of women from the point of pregnancy planning through to the end of breastfeeding. Methods We performed a retrospective cohort study of 747 women in the first trimester of pregnancy attending a private antenatal clinic in Ballarat from November 2005 to July 2013. Iodine concentrations in urinary samples were used as a representative for dietary iodine intake. We compared results between women prior to (Group 1, n = 360) and after (Group 2, n = 387) the commencement of the iodine fortification programme. The WHO epidemiological criteria for assessing iodine nutrition in pregnant women were used for data interpretation. Results Pregnant women in Group1 demonstrated mild iodine deficiency with a median urinary iodine concentration (MUIC) of 83 micrograms/L. A significant increase was noted in Group 2 to a MUIC of 163 micrograms/L (P < 0.0001), corresponding to an adequate dietary iodine intake. Of concern we noted an increase in women with excessive dietary iodine from 2% in Group 1 to 6.1% in Group 2 (P < 0.001). Conclusion This study has confirmed that pregnant women in West Victoria were iodine deficient. We have demonstrated that the Australia-wide pubic health campaigns were successful in increasing the dietary iodine intake in this population. Our study supports the need to continue to educate women and healthcare providers of the importance of iodine supplementation from preconception through to breastfeeding, in iodine deficient regions. In addition we have raised the need for further studies to investigate the perinatal impacts of oversupplementation.