Restoration of the gonadotrophin response to LH-RH and oestrogen administration in patients after molar abortion

Abstract

The relation of the hypothalamic-pituitary effect on gonadotrophin secretion and the concentration of serum hCG after molar abortion was investigated. Gonadotrophin release after a bolus injection of LH-RH or conjugated oestrogens was observed in 17 women until 5 months after molar abortion. Little if any response of gonadotrophin was observed at a hCG level of 100 mIU/ml or more, but the response of LH and FSH to LH-RH were restored to normal when the serum hCG level decreased to below 100 mIU/ml. A normal response of LH to conjugated oestrogens was observed at a serum hCG level of 20 mIU/ml or less. These findings suggest that a high level of hCG interferes with pituitary gonadotrophin secretion, that the threshold hCG levels for normal responses of gonadotrophins to LH-RH and oestrogen are 100 and 20 mIU/ml, respectively, and that secretion of gonadotrophins is restored even in the presence of a low hCG level.

PIP: The effect of serum human chorionic gonadotropin (hCG) level on gonadotropin response to a single intravenous injection of luteinizing hormone-releasing hormone (LH-RH) or conjugated estrogen (Premarin) was investigated in patients after abortion of a hydatidiform mole. 17 women (aged 23-29 years) with an aborted mole without theca lutein cyst were examined until 5 months after molar abortion. Response to gonadotropin was little at a hCG level of 100 mIU/ml or more, but the response of LH and follicle stimulating hormone (FSH) to LH-RH was restored to normal when the serum hCG level decreased to below 100 mIU/ml. A normal response of LH to conjugated estrogens was observed at a serum hCG level of 20 mIU/ml or less. Apparently, a high level of hCG interferes with pituitary gonadotropin secretion. The threshold hCG levels for normal responses of gonadotropins to LH-RH and estrogens are 100 and 20 mIU/ml, respectively. The secretion of gonadotropins was restored even in the presence of low hCG with either LH-RH or conjugated estrogen induction.