Review Article

Screening for Maternal Thyroid Dysfunction in Pregnancy: A Review of the Clinical Evidence and Current Guidelines

Box 1

Screening recommendations for thyroid disorders in pregnancy.
Joint Guidelines from the American Association of Clinical Endocrinologists and the American Thyroid Association
(2012) [10]
Universal screening is not recommended for patients who are pregnant or are planning pregnancy, including assisted reproduction. Aggressive case finding, rather than universal screening, should be considered for patients who are planning pregnancy.
The Endocrine Society (2012) [11]
The committee could not reach agreement with regard to testing recommendations for all newly pregnant women, therefore 2 versions were presented.
(1) Some members recommended screening of all pregnant women for serum TSH abnormalities by the ninth week or at the time of their first visit.
(2) Some members recommended aggressive case finding to identify and test high-risk women (see Box 2) for elevated TSH concentrations by the ninth week or at the time of their first visit before or during pregnancy, and they recognize that in some situations ascertainment of the individual’s risk status may not be feasible. In such cases, and where the local practiceenvironment is appropriate, testing of all women by week 9 of pregnancy or at the first prenatal visit is reasonable (see Box 2).
American Thyroid Association (2011) [12]
Universal screening of healthy women for thyroid dysfunction before pregnancy is not recommended. However, caregivers should identify individuals at high risk for thyroid illness (see Box 2) on the basis of their medical history, physical exam, or prior biochemical data.
The Cochrane Collaboration (2010) [13]
Until convincing data from randomised-controlled trials become available, targeted thyroid function testing in pregnancy should be implemented in women at risk for thyroid disease (e.g., pregestational diabetics), those with a family history of thyroid disease and symptomatic women. Consideration could be given to screening women with a personal history of preterm birth or recurrent miscarriage. At present, universal screening would not be based on firm evidence.
Society of Maternal-Fetal Medicine (2012) [14]
Current recommendations include thyroid testing for pregnant women “at risk,” such as those with known thyroid disease, symptoms of overt thyroid disease, suspected goiter, and autoimmune medical disorders such as Type 1 diabetes mellitus.
American College of Obstetrics and Gynecology (2007) [15]
Based on current literature, thyroid testing in pregnancy should be performed on symptomatic women and those with a personal history of thyroid disease or other medical conditions associated with thyroid disease (e.g., diabetes mellitus). Without evidence that identification and treatment of pregnant women with subclinical hypothyroidism improves maternal or infant outcomes, routine screening for subclinical hypothyroidism currently is not recommended.