Iodine is a substance we take for granted in developed countries, but as J. C. Dillon and J. Milliez point out (pages 631–636) deficiency of iodine is an important cause of miscarriage and stillbirth in the developing world. The authors conducted an observational survey of 2490 women chosen by cluster random sampling in two iodine-deficient areas of Senegal. The women underwent clinical examination of the thyroid gland, their weights and heights were measured and the urinary excretion of iodine estimated in order to determine their iodine status. Their obstetric histories were recorded and the number of women with reproductive failure, defined as three or more miscarriages or one or more stillbirths, was estimated.

The most important result of the study was a dose-response relationship between the severity of iodine deficiency and reproductive failure, such that women with severe iodine deficiency had over three times the risk of reproductive failure compared with women without iodine deficiency. There were also associations between malnutrition and illiteracy and reproductive failure, but the risks of reproductive failure in these situations were increased by iodine deficiency, suggesting interactions between iodine deficiency and malnutrition and iodine deficiency and illiteracy.

The results of this survey confirm those of others in Papua New Guinea, Central Africa and the Himalayas, that deficiency of iodine is an important cause of reproductive failure. The remedy seems disarmingly simple: add iodine to table salt; but like most simple remedies in the developing world implementation may hampered by geographical difficulties in distribution.