Gonadotropin-releasing hormone agonist and human menopausal gonadotropin (hMG) short protocol, but not hMG alone, rescues the corpus luteum from the preceding cycle.

OBJECTIVE

To determine whether ovulation induction regimens, particularly the short protocol, has an effect on the corpus luteum (CL) from the previous cycle.

DESIGN

Infertility patients were followed in an academic research environment. Patients were treated with either the short protocol (GnRH agonist [GnRH-a] and hMG) or hMG alone in a controlled ovarian hyperstimulation cycle.

SETTING

Infertility center in academic setting.

PATIENTS: Patients requiring ovulation induction.

INTERVENTIONS: The blood samples were drawn on day 2 or 3 as a baseline before initiation of any treatments, generally on day 5 and usually every other day thereafter until ovulation. Serum P, E2, and relaxin were determined.

MAIN OUTCOME MEASURES: Serum P, E2 and relaxin.

RESULTS

Patients receiving hMG alone showed no change in serum P levels in the first few days of treatment whereas most short-protocol patients (18/30; 60%) showed an increase of P within 3 days of the initiation of treatment. The increase in P almost always was associated with an increase in relaxin as a marker of the luteal production of this P.

CONCLUSION

The short protocol with its flare of gonadotropins is able to stimulate the CL from the previous cycle, resulting in an early increase in P that comes from the CL as indicated by its association with an increased relaxin in the same subjects.