The treated antibody-positive women had a miscarriage rate of 3%, similar to the rate in the control group, 2%. But the untreated antibody-positive women had a rate of 14%. The treated women had a premature delivery rate of 7%, similar to the 8% for the control group. That compared with a rate of 22% for the untreated women.
Given those findings, Dr. Mestman recommended that antibody-positive euthyroid women who are pregnant should be treated. The treatment should include a prenatal vitamin with 150 mcg of iodine, because there is some suggestion that many Americans may no longer get adequate iodine in their diet. And they should have their TSH and T4 levels monitored every 4-6 weeks during the first 20 weeks of pregnancy.
After 20 weeks, they should have their TSH and T4 measured once at 28 weeks. In addition, they should be treated with 50-75 mcg a day of levothyroxine. If the patient is already on levothyroxine at the time, the dose should be increased by 25 mcg.
“Early treatment prevents all the known complications,” Dr. Mestman said.