This version first published online:
October 21. 1996
Last assessed as up-to-date:
July 29. 1997
Abstract
Background
Iodine deficiency is the leading preventable cause of intellectual impairment in the world. Although iodine supplementation is generally considered to be safe, there is a possibility of high doses of iodine suppressing maternal thyroid function.
Objectives
The objective of this review was to assess the effects of iodine supplementation before or during pregnancy in areas of iodine deficiency.
Search strategy
We searched the Cochrane Pregnancy and Childbirth Group trials register.
Selection criteria
All acceptably controlled trials of maternal iodine supplementation during pregnancy with clinical outcomes.
Data collection and analysis
Eligibility and trial quality were assessed by two reviewers.
Main results
Three trials involving 1551 women were included. In two trials, iodine supplementation was associated with a statistically significant reduction in deaths during infancy and early childhood (relative risk 0.71, 95% confidence interval 0.56 to 0.90). Iodine supplementation was associated with decreased prevalence of endemic cretinism at the age of four years (relative risk 0.27, 95% confidence interval 0.12 to 0.60) and better psychomotor development scores between four to 25 months of age.
Authors' conclusions
Iodine supplementation in a population with high levels of endemic cretinism results in an important reduction in the incidence of the condition with no apparent adverse effects.