Alert for TSH Measurement in High-Risk Pregnancies in Brazil

Introduction: The hypothyroidism during pregnancy can lead to alterations in fetal neurological formation and has metabolic impact on pregnant women. If not diagnosed and treated it can cause complications during pregnancy and childbirth, besides causing changes in fetal formation. The TSH test is not part of routine examinations of the pregnancy monitoring care in Brazilian public health system (SUS). The test is not requested in low-risk pregnant women like those at high risk. The Overt Hypothyroidism (no subclinical) is prevalent in 0.3% to 0.5% of pregnant women and is asymptomatic in 70% of these patients. Thus, in order to avoid risks to the mother and fetus health due absence of early diagnosis, it would be ideal for pregnancy monitoring care examinations in the public health system to request a TSH test, especially in high-risk pregnancies. Method: A cross-sectional observational study was approved by the Ethics Committee (CAAE 22906619.2.0000.0062) to review 83 medical records of high-risk pregnant women in a Brazilian public hospital, State of São Paulo, Brazil in 2020. Inclusion criteria: All patients who are being followed up in high-risk childbirth or are hospitalized in the high-risk sector on the maternity during the year 2020. Complete medical records containing the data proposed to be researched and results of exams to be analyzed in the research. Results: The study included the review of 83 medical records of high-risk pregnant women with average age of 30 years old, average gestational age of 31 weeks and average weight of 84 kg. From these 11.4% (n = 10) declared that they had hypothyroidism and 2.4% (n = 2) hyperthyroidism in the first consultation. The 47% (n = 39) had their TSH measured during pregnancy, of which TSH had changed 30.8% (n = 12), 5.1% (n = 2) with suppressed TSH and 25.6% (n = 10) with TSH above the limit for pregnancy. Of the pregnant women who had a diagnosis prior to the pregnancy of hypothyroidism, only 1 did not have their TSH collected during pregnancy. Of the pregnant women who had hyperthyroidism, all had TSH collected during pregnancy, but kept TSH suppressed and free T4 at the upper limit throughout the pregnancy. 10% (n = 8) had gestational bleeding, of which only 25% (n = 2) had TSH measured at some point during pregnancy, of these, one had an altered TSH, but no medication was prescribed or the test repeated. Conclusion: Recognizing that the evolution of pregnancy depends on the normal thyroid eixo, we believe that for high-risk pregnant women they should have their thyroid eixo evaluated in the first trimester.