Targeted thyroid testing during pregnancy in clinical practice

Area of Science:

• Endocrinology
• Obstetrics
• Public Health

Background:

• Thyroid dysfunction in pregnancy can impact maternal and fetal outcomes.
• Current clinical practice often employs targeted thyroid testing based on symptoms or risk factors.

Purpose of the Study:

• To evaluate the effectiveness of a targeted thyroid testing strategy in pregnant women within a real-world clinical setting.
• To compare the prevalence of thyroid dysfunction markers between women who underwent targeted testing and those who did not.

Main Methods:

• Retrospective cohort study of 5,254 pregnant women in Uppsala County, Sweden.
• Analysis of thyrotropin (TSH), free thyroxine, and thyroid peroxidase antibodies in targeted tested (n=891) and randomly selected untested women (n=1,006).
• Comparison of trimester-specific TSH levels against International Endocrine Society Guidelines.

Main Results:

• No significant difference in the proportion of trimester-specific elevated TSH between targeted tested (12.6%) and untested (12.1%) groups (P=.8).
• Similar prevalence of overt hypothyroidism in both groups (1.1% vs. 0.7%, P=.4).

Conclusions:

• Targeted thyroid testing in clinical practice is insufficient for identifying pregnant women with elevated TSH or overt hypothyroidism.
• Universal thyroid testing may be a more appropriate strategy if evidence supports treatment for elevated TSH in pregnancy.