Evaluation of different ovarian stimulation protocols for in vitro fertilization

In this study we evaluated retrospectively the efficacy of five different ovarian stimulation protocols in an in vitro fertilization program, in which 512 women were involved. Ovulation was induced by the following protocols: group I (271 cycles): buserelin short protocol (1 mg/day, intranasally) with human menopausal gonadotropin/human chorionic gonadotropin (hMG/hCG); group II (45 cycles): buserelin (short protocol) with pure follicle stimulating hormone (p-FSH)/hMG/hCG; group III (24 cycles): clomiphene citrate (100 mg/day) with hMG/hCG; group IV (122 cycles): hMG (3 ampules/day) and hCG; group V (113 cycles): hMG/hCG and prednisolone (7.5 mg/day) after cycle programming with oral contraceptives. The lowest cancellation rate (3.3%) was noted in group I, followed by group V (9.7%). The highest number of follicles was observed in groups I (8.3 +/- 0.3; mean +/- SEM) and V (7.8 +/- 0.5). Also, more oocytes were retrieved in group I (7.2 +/- 0.3, p < 0.001), which were of good quality based on oocyte maturity as well as on the fertilization rate, and more embryos (4.5 +/- 0.3, p < 0.05) were developed. The correlation between estradiol and the total follicular volume on the day of hCG administration was also examined in the five groups. The best correlation (r = 0.6502) was found in group I, followed by group V (r = 0.5810). Significant differences were observed in the five groups with regard to the number of hMG ampules administered (p < 0.0001, F = 15.393) and the stimulation days (p < 0.0001, F = 35.32). Sixty-six clinical pregnancies were achieved: 37 (17.5%) in group I, seven (25.9%) in group II, one (10%) in group III, ten (15.6%) in group IV and 11 (15.5%) in group V (differences were not statistically significant). In conclusion, all five protocols were satisfactory in ovarian stimulation for in vitro fertilization, and gonadotropin releasing hormone (GnRH) analogs seemed to be more advantageous by reducing the cancellation rate, enhancing the number of oocytes retrieved and embryos developed and by improving the pregnancy rates.