Prevalence of overt and subclinical hypothyroidism during pregnancy in antenatal care - cross-sectional study, Jeddah, Saudi Arabia

Objective To estimate the prevalence of subclinical and overt hypothyroidism in antenatal care clinics To evaluate the performance of targeted screening approach based on the risk stratification as recommended by the U.S. Preventive Service Task Force (USPSTF) and adopted by the American Thyroid Association (ATA) Method: This was a multicenter, cross-sectional study conducted in 386 pregnant women attending routine antenatal visits at 4 antenatal clinics from September 2019 to August 2020. All participants underwent clinical and thyroid function test (TFT) including TSH and T4 levels. Based on risk factor assessment, participants were categorized into low-risk versus high-risk patients. The performance of targeted screening was assessed by comparing the two categories regarding the prevalence of subclinical and overt hypothyroidism and calculating the associated sensitivity, specificity and accuracy. Result: Overall, the prevalence of dysthyroidism was 11.7% (95% CI=8.6-15.3%) with 10.4% subclinical hypothyroidism and 1.3% overt hypothyroidism cases. No difference in the prevalence of dysthyroidism was found between low-risk and high-risk patients. The performance of the risk stratification-based screening approach in detecting subclinical or overt hypothyroidism showed sensitivity (73.3% and 86.7%), specificity (30.2% and 13.2%), and accuracy (35.2% and 21.8%), using the USPSTF alone and combined with the ATA criteria, respectively. Conclusion: The application of the targeted screening for subclinical and overt hypothyroidism using the USPSTF and ATA criteria performed poorly in the studied population. Thus, universal screening appears to be a better option.