Production of Human Chorionic Gonadotropin During the Normal Menstrual Cycle

OBJECTIVE: To present a comprehensive study of pituitary human chorionic gonadotropin (hCG) production during the menstrual cycle, investigating its occurrence, timing and the possibility of a separate biologic role for pituitary hCG during the normal menstrual cycle. STUDY DESIGN: Daily urine samples were tested from 185 women during 405 normal menstrual cycles. Levels of hCG and luteinizing hormone (LH) were measured daily. RESULTS: hCG levels were detected at LH peak in 84% Of menstrual cycles. At this time, hCG levels paralleled LH values. The remaining menstrual cycles (16%) had significantly lower LH levels, suggesting lack of detection of hCG as a result of low concentration of LH or very dilute urines. We infer that hCG is produced in all menstrual cycles. CONCLUSION: hCG is seemingly produced alongside LH in all menstrual cycles. hCG has a much greater circulating half-life compared to LH. It may function to extend the short, sharp LH peak in promoting ovulation or in promoting initial progesterone production by the corpus luteal cells. (J Reprod Med 2009;54:245-250)