Patients who failed to conceive after gonadotropin stimulation in in vitro fertilization treatment were classified into normal, high, or poor responders. They were routinely offered another cycle with a combination of a gonadotropin releasing hormone agonist and gonadotropin therapy (in order to evaluate whether this combined therapy could improve their response). The gonadotropin-induced cycle was compared with the combined therapy cycle. With the combination treatment, in the normal responders the phase of ovarian stimulation was significantly (P < 0.001) prolonged, and the number of follicles and oocytes collected (5.7 +/- 0.7 vs 3.1 +/- 0.4) was increased, without any change in serum estradiol level compared to the control cycle. In high responders the number of oocytes was not modified by the combined treatment compared with the control cycle. However, serum estradiol level was significantly (P < 0.005) decreased. The combined therapy did not modify any parameter of response in poor responders. We conclude that the response to combined agonist/gonadotropin therapy is dependent on the patient's own basal response. No improvement in response was expected in poor responders.
