Posthemithyroidectomy Pregnancy Thyroid Function Surveillance: Frequency, Adherence, and Guideline Impact

Abstract

Objective: Posthemithyroidectomy women are at an increased risk for gestational subclinical hypothyroidism. Therefore, the American Thyroid Association (ATA) recommends increased thyroid function surveillance for this subgroup of pregnant women. The purpose of this study was to evaluate the frequency of thyroid function surveillance during pregnancy in posthemithyroidectomy women and to evaluate the adherence to the 2017 ATA guidelines and its possible impact since being published on thyroid function surveillance rates.

Methods: A retrospective study of pregnant posthemithyroidectomy women operated at our institution between 1997 and 2020 was performed. The study cohort was subdivided by pregnancy dates before 2018 and 2018 onward to evaluate the impact of the 2017 ATA guidelines. Adherence to the guidelines was defined as at least 1 thyroid-stimulating hormone test in each trimester.

Results: After exclusions, a total of 120 pregnancies conceived by 66 women who underwent hemithyroidectomy surgeries were included in this study. Overall, serum thyroid-stimulating hormone examinations were performed during the first, second, and third pregnancy trimesters in 86.6%, 40%, and 16.6% of pregnancies, respectively (P <.005). The examination rate since 2018 was 88%, 40%, and 8% for the first, second, and third trimesters, respectively (P <.005).

Conclusion: Adherence to the latest ATA guidelines is low, and its publication in 2017 did not increase the thyroid function surveillance rate in posthemithyroidectomy women. Better patient education regarding the risks of gestational hypothyroidism following hemithyroidectomy and improved communications among treating surgeons, obstetricians, and endocrinologists may improve these rates.

Keywords: TSH; hypothyroidism; pregnancy; pregnancy trimesters; thyroidectomy.