We read with interest Dr Melnick’s letter regarding his perspective on the current controversy over routine thyroid screening during pregnancy. There is no dispute that untreated overt hypothyroidism poses significant risks to both mother and fetus, and we agree that it is important to identify and treat such women before or during pregnancy. However, a majority of the women included in his incidence estimates do not have overt hypothyroidism. Rather, most are women with subclinical thyroid disease. Importantly, identification and treatment of these women during pregnancy, in contrast to those with overt disease is very much in dispute. The American College of Obstetricians and Gynecologists currently recommends against universal screening and continues to support a risk-based approach until there is evidence of treatment benefit in women with subclinical hypothyroidism or their offspring.

In his letter, Dr Melnick shares data from his practice on the individual cost of thyroid testing and writes in support of routine comprehensive screening to identify women with variously defined hypothyroidism. Contrary to his view though, a recent cost-effectiveness analysis of routine screening to detect overt hypothyroidism indicated that such a policy does not meet recommended US cost-effectiveness thresholds. Furthermore, a health insurance carrier’s willingness to cover such expenses is not a very compelling justification for routine screening, especially in the light of increasing health care costs across the United States. Finally, a recently completed international multicenter trial of identification and treatment of subclinical thyroid dysfunction during pregnancy did not result in improved cognitive function in offspring at 3 years of age. Studies of treatment benefit on immediate pregnancy outcomes in such women are, to quote Dr Melnick, “conflicting and differ methodologically.” It is anticipated that the findings of the soon-to-be-completed study from the Eunice Kennedy Shriver National Institute of Child Health and Human Development’s Maternal-Fetal Medicine Units Network will help answer the important screening and treatment questions raised in Dr Melnick’s letter.