Comparison of outcomes and direct cost between minimal stimulation and conventional protocols on ovarian stimulation in in vitro fertilization

AIM: To determine whether minimal stimulation with clomiphene and gonadotropin provides outcomes and direct costs comparable with those of a conventional GnRHa-gonadotropin stimulation protocol for infertile patients undergoing in vitro fertilization. METHODS: A non-randomized clinical trial was conducted from 1 July 1996 to 31 March 2003 at the Infertility and Assisted Reproductive Unit, Ramathibodi Hospital, Faculty of Medicine, Mahidol University, Thailand. A total of 192 patients were recruited of whom 96 cases underwent ovarian stimulated cycles with minimal stimulation protocol, and 96 controls underwent ovarian stimulated cycles with GnRHa-gonadotropin protocol, with cases and controls matched for age and infertility cause. RESULTS: The median patient age was 35 years. Endometriosis was the most frequent infertility cause (28.1%). The conventional GnRHa-gonadotropin protocol could give more oocyte numbers than the minimal stimulation protocol (7.3 +/- 4.9 vs 4.5 +/- 3.3 oocytes). The fertilization rate and cleavage rate were similar (73.4 +/- 31.9 and 84.9 +/- 32.6 in minimal stimulation protocol, 69.3 +/- 29.6 and 88.4 +/- 28.0 in GnRHa-gonadotropin protocol, respectively). The pregnancy rate per oocyte retrieval cycle in the GnRHa-gonadotropin protocol was similar to the minimal stimulation protocol. (13.1%vs 13.0%, P = 1.000). However, the cost per pregnancy of minimal stimulation protocol was less than that of GnRHa-gonadotropin protocol. (6021.95 US dollars for minimal stimulation protocol per pregnancy, 10,785.65 US dollars for GnRHa-gonadotropin protocol per pregnancy, P < 0.000). CONCLUSION: Minimal stimulation was less effective than conventional GnRHa-gonadotropin on the ovarian stimulation. However, the total costs of minimal stimulation were cheaper than the conventional GnRHa-gonadotropin protocol. The decreased costs of minimal stimulation justifies further evaluation of its role in the treatment of infertility in selected cases.