ABSTRACT
The purpose of this cross-sectional study was to determine the correlation of beta subunit human chorionic gonadotropin (beta-hCG) level in the serum and first morning urine samples of patients with gestational trophoblastic disease (GTD). A total of 81 paired serum and first morning urine samples from 24 patients diagnosed with GTD, who had their follow-up at the Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University. The paired serum and first morning urine samples were measured for beta-hCG level, using enzyme-linked immunosorbent assay (ELISA). After logarithmic transformation, serum beta-hCG level was strongly and significantly correlated to those of first morning urine samples, with the correlation coefficient of 0.97 (p < 0.01). Among the disease-remission group (serum beta-hCG of less than 5 mIU/ml), the correlation coefficient was 0.52 (p < 0.01), which was still statistically significant. Stronger statistical significance was found in the disease-active group (serum beta-hCG of 5 mIU/ml or higher), with the correlation coefficient of 0.95 (p < 0.01). We concluded that the level of serum beta-hCG was strongly and significantly correlated with those of first morning urine samples, especially in patients with active disease. Determination of beta-hCG level using first morning urine samples can be used as an effective mean in the follow-up of patients with GTD.