Background:
Gestational trophoblastic disease (GTD) is a rare complication of pregnancy, ranging from molar pregnancy to choriocarcinoma. Occasionally, GTD is complicated by hyperthyroidism, which may require treatment. This is thought to occur due to molecular mimicry between human chorionic gonadotrophin (HCG) and thyroid-stimulating hormone (TSH), and hence cross-reactivity with the TSH receptor. Hyperthyroidism develops in 5-10% cases of GTD and an incidence up to 78,8% is reported in Indonesia. Hyperthyroidism usually resolves as the GTD is successfully treated and correspondingly HCG levels normalise.
Objective:
This study aimed to determine clinical thyrotoxicosis and hormonal characteristics in patients with GTD in our hospital.
Methods:
A retrospective study was carried out from January 2013 to November 2017 in Hasan Sadikin General Hospital Indonesia. All the relevant data were collected from medical records.
Results :
Ninety three patients with GTD were identified, consisted of 64 complete moles, 24 partial moles, 1 persistent gestational trophoblastic tumor, 1 choriocarcinoma, and 3 invasive moles. Median distribution was at 34 years of age. Eighty-five percents patients had TSHs level <0.3 uIU/mL (both clinical and subclinical hyperthyroidism) and 15% had TSHs > 0.3 uIU/mL (no hyperthyroidism). Among patients with TSH level <0.3 uIU/mL, βhCG levels >300.000 uIU/mL, 100.000-300.000 uIU/mL, and <100.000uIU/mL were 43.33%, 23.33%, and 33.33% respectively.
Conclusion:
Concomitant biochemical thyroid disease in patients with GTD is relatively common. Measurement of thyroid function in patients with persistent GTD is important. Extremely high levels of HCG are typically required for the development of clinical hyperthyroidism as the relative potency of HCG for the TSH receptor is low. As a result, only a minority are clinically hyperthyroid and require treatment, although rarely the thyroid stimulation can have potentially lifethreatening consequences. However, a GTD may have a normal hCG level with suppressed TSHs.
Keywords: Gestational trophoblastic disease, hyperthyroidism