“…(20) In a recent study conducted in the city of Rio de Janeiro, 41.2% of pregnant women would remain undiagnosed because they did not meet any criteria for selective screening. (21) Thus, thyroid dysfunction during pregnancy presents high prevalence and is usually asymptomatic or oligosymptomatic. On the other hand, the serum TSH measurement, considered the test of choice for the diagnosis of thyroid dysfunction, is a sensitive, simple, robust, low-cost and widely available test, in addition to not offering risks to the patient when applied.…”