Pregnancy Thyroid Screenings

Thyroid reduction is problematic for mother and fetus

(RxWiki News) For women who are pregnant, reduced thyroid function can have adverse effects on both the woman's health, and that of her unborn baby. These effects can include the risk of miscarriage and premature birth, but the universal screening of pregnant women for thyroid disfunction is still controversial due to costs.

Thyroid autoimmunity, in which a person's immune system attacks and damages the thyroid, also puts the mother at higher risk of developing postpartum thyroiditis (swelling of the thyroid) and hypothyroidism (low thyroid hormone production).

"Pregnant women should ask their doctor about thyroid screening."

Only women at high risk for developing thyroid dysfunction are recommended for screening traditionally. Chrysoula Dosiou, MD, of Stanford University School of Medicine, and colleagues from several other universities the University developed a computer model to compare the cost-effectiveness of three screening strategies: universal screening with thyroid-stimulating hormone and anti-thyroid peroxidase antibodies during the first trimester, risk-based screening, and no screening.

Patients who receive a positive screening test would receive follow-up testing and treatment with thyroid hormone when indicated, under the developed model. The model takes into account the development of adverse obstetrical outcomes during pregnancy, postpartum thyroiditis, and overt hypothyroidism during a woman's lifetime.

Using the model, researchers found that universal screening for autoimmune thyroid disease in the first trimester of pregnancy is cost-effective compared with screening of only high-risk women. Both the risk-based and universal screening options are cost-effective when relative to no screening.

"Interestingly, the current guidelines do not support universal screening," says Jennifer Mushtaler, MD and an obstetrician in Austin, Texas. "However, the risks associated with untreated hypothyroidism in pregnancy are well-known. It is good to see a model that evaluates the cost-benefit profiles in the general population to show merit to universal screening."

Findings from the model study were presented at the 81st Annual Meeting of the American Thyroid Association in October 2011. 

Review Date: 
November 3, 2011