According to an editorial, these results are consistent with those of the CATS trial, with some important differences. Unlike the CATS cohort, the current trial participants were iodine-sufficient. Also IQ was assessed at 5 years of age, which may be more predictive of long-term outcomes than assessment at 3.5 years of age, as was done in the CATS trial, and follow-up in the present trials was more complete than in the CATS trial. It adds that all the studies were limited by the late initiation of treatment, which is relevant because the foetal thyroid becomes functional at 16 to 20 weeks gestation. It notes that although the findings indicate that screening and treatment for subclinical hypothyroidism, if performed well into the second trimester of pregnancy, are unlikely to be beneficial, because more than 75% of women in US have their first prenatal visit before 12 weeks of gestation, earlier treatment appears to be feasible. The authors of the editorial say that they “continue to endorse the recent guidelines of the American Thyroid Association, since the early initiation of low-dose levothyroxine therapy for subclinical hypothyroidism may be of benefit is inexpensive, and is unlikely to be harmful.”