Cessation of low-dose gonadotropin releasing hormone agonist therapy followed by high-dose gonadotropin stimulation yields a favorable ovarian response in poor responders.

PURPOSE: This study is a prospective nonrandomized study to determine the effect of a new protocol of controlled ovarian hyperstimulation (COH) using low doses and a half-period of gonadotropin releasing hormone agonist (GnRHa) followed by high doses of gonadotropin in patients who were supposed to be poor responders to standard long protocols of GnRHa administration.

METHODS

From Dec 1996 to Nov 1998, 50 patients who were classified as "poor responders" were scheduled for 52 cycles of a modified controlled ovarian hyperstimulation protocol. They were categorized into 3 groups: a group of poor responders to COH in the previous IVF or IUI cycles, a group with elevated Day 3 FSH levels, and a group over the age of 40 years. All patients received GnRH agonist from the midluteal phase of the previous cycle to the onset of menstruation in the next cycle. Then high doses of gonadotropins (HMG/FSH) were given. The patients then had standard courses of in vitro fertilization and embryo transfer (IVF-ET) or transfallopian embryo transfer (TET).

RESULTS

Six of the 52 cycles of the modified protocols were cancelled because of poor ovarian response. One premature ovulation was noted before ovum retrieval was performed. In the other 45 cycles, an average of 6.3 mature oocytes were retrieved. The total pregnancy rate and implantation rate were 20.5 and 11.5%, respectively.

CONCLUSIONS

The low dose and half duration of GnRHa therapy lessened the suppression of the response of the ovaries to COH compared with the regular long protocol of GnRHa down regulation therapy. This resulted in a low cancellation rate (11.8%), a favorable embryo implantation rate (11.5%), and an acceptable clinical pregnancy rate (20.5%).