Thyroid function in trophoblastic disease.

Human chorionic gonadotrophin (hCG) levels and thyroid function were monitored in 44 patients receiving chemotherapy for treatment of trophoblastic disease. We observed a strong correlation between hCG and thyroid stimulating hormone (TSH) concentrations measured by radioimmunoassay, and this appears to be due to cross-reactivity between hCG and the anti-TSH antibody used. The concentration of thyroid hormones was little affected by the raised levels of TSH or hCG, except when the concentration of the latter rose to high levels, usually above 100,000 i.u./l. The possible mechanisms of thyroid homeostasis in trophoblastic disease are considered.