Secretion and excretion of human chorionic gonadotropin during early pregnancy.

Objective: To characterize the profiles of human chorionic gonadotropin (hCG) secretion in blood and its subsequent excretion in urine during conceptive cycles that ended in successful pregnancy and in spontaneous abortion.

Design: A prospective study.

Setting: University fertility clinic and research laboratories.

Patient(s): Healthy, spontaneously ovulating women with regular menses, no history of infertility, and either no male partner or an azoospermic partner.

Intervention(s): Blood and urine samples were collected daily from 63 spontaneously ovulating women during 167 cycles of artificial insemination (AI) with donor semen; hCG concentrations were measured in blood and urine, and luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations were measured in blood by immunoassay.

Main Outcome Measure(s): Fecundity, the day of ovulation, the day of hCG detection, and the concentration of hCG on the day of detection in blood and urine.

Result(s): In 62 conceptions detected, 14 resulted in clinical spontaneous abortion (CAB) and 8 resulted in early pregnancy loss (EPL). When successful pregnancies and pregnancy losses were compared, no significant differences existed between the days of hCG appearance in serum or in urine, the concentrations of hCG on the day of detection, or the incremental change in hCG concentration on the day of detection.

Conclusion(s): These data validate the use of urinary hCG as a biomarker for assessing peri-implantation pregnancy events.