SUMMARY OF THE STUDY
The investigators administered a questionnaire at the first 12-week appointment of 2198 pregnant women in the Netherlands who did not have a history of thyroid dysfunction, autoimmune disease, twin or in-vitro fertilization pregnancy and who were not taking medications that interfere with thyroid function. The questionnaire used a 5 point scale to assess for the presence of symptoms typical of hypothyroidism. Participants also had blood tests for serum TSH, Free T4 and thyroid peroxidase (TPO) antibody levels measured around the same time. The authors defined “treatment requiring hypothyroidism” as those with high TSH and low free T4 level (called overt hypothyroidism) as well as those with normal T4 but a TSH level over 10mIU/L (called subclinical hypothyroidism). They then compared those who reported high scores based on the questionnaire with those who had treatment requiring hypothyroidism based on the blood tests.
A total of 302 women reported high symptom scores for hypothyroidism based on the questionnaire and 15 women (0.7% of entire group) had treatment requiring hypothyroidism based on blood tests. Only 1 of the 302 women with a high symptom score was actually found to have treatment requiring hypothyroidism. As such high symptom scores for hypothyroidism did not predict true hypothyroidism based on blood tests.
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study suggests that symptoms alone, in the absence of laboratory tests, do not predict hypothyroidism in pregnant women. Many of the symptoms of hypothyroidism overlap with the symptoms of pregnancy and, as such, clinicians must evaluate for other risk factors of hypothyroidism in order to identify pregnant women who should receive screening blood tests.
— Philip Segal, MD
ATA THYROID BROCHURE LINKS
Thyroid Disease and Pregnancy: https://www.thyroid.org/thyroid-disease-pregnancy/
Hypothyroidism (Underactive): https://www.thyroid.org/hypothyroidism/
Thyroid Function Tests: https://www.thyroid.org/thyroid-function-tests/