How is hypothyroidism in pregnancy diagnosed?
Like hyperthyroidism, hypothyroidism is diagnosed through a careful review of symptoms and measurement of TSH and T4 levels. Symptoms of hypothyroidism in pregnancy include extreme fatigue, cold intolerance, muscle cramps, constipation, and problems with memory or concentration. High levels of TSH and low levels of free T4 generally indicate hypothyroidism. Because of normal pregnancy-related changes in thyroid function, test results must be interpreted with caution. The TSH test can also identify subclinical hypothyroidism—a mild form of hypothyroidism that has no apparent symptoms. Subclinical hypothyroidism occurs in two to three of every 100 pregnancies.4 Test results will show high levels of TSH and normal free T4. Experts have not reached a consensus as to whether asymptomatic pregnant women should be routinely screened for hypothyroidism. But if subclinical hypothyroidism is discovered during pregnancy, treatment is recommended to help ensure a healthy pregnancy.
