The pregnancy rate was found to be higher when GnRHa was used in a long protocol as compared to a short or ultrashort protocol. There was no evidence of a difference in live birth rate, but this outcome was only reported by three studies. There was no evidence of a difference in the outcomes amongst various long protocols; nor that stopping or reducing GnRHa at the start of stimulation was associated with a reduced pregnancy rate. For all comparison, except a long versus short protocol, there was a lack of power.
A comparison between a standard and reduced dose of D-Trp-6-luteinizing hormone-releasing hormone administered after pituitary suppression for in-vitro fertilization.
A randomized prospective study was undertaken to compare low and standard luteinizing hormone-releasing hormone agonist (LHRHa) dosage used in combination with gonadotrophins in ovarian stimulation for in-vitro fertilization (IVF). A total of 42 ovulatory patients with mechanical infertility were administered 0.5 mg/day LHRHa (Decapeptyl) from day 21 of their cycles for 14 days. Following down-regulation, patients were randomly allocated to continue with the same dose of LHRHa (22 patients, group A) or to receive a lower dose of 0.1 mg/day LHRHa (20 patients, group B) during folliculogenesis. Luteal phase was supported by daily i.m. progesterone (50 mg) injections and human chorionic gonadotrophin (HCG; 1500 IU) every 4 days. Ovarian response, human menopausal gonadotrophin (HMG) dosage used for induction of ovulation, evidence of premature luteinization, and clinical and laboratory IVF outcome, were compared between groups A and B. The two groups were comparable in respect of: age (32.6 +/- 0.7 and 33.0 +/- 0.9 years), HMG dosage (33.0 +/- 1.6 and 36.0 +/- 2.5 ampoules), day of HCG (11.2 +/- 0.3 and 12.2 +/- 0.4), oocytes/patient (13.3 +/- 1.0 and 12.9 +/- 1.3), fertilization rate (68.5 and 65.2%), cleavage rate (95% for both), pregnancy/embryo transfer (32 and 35%) and implantation rate (10.8 and 10.5%), for groups A and B respectively. There was no evidence of premature luteinization or luteolysis in either group. It was concluded that lowering the dose of LHRHa to 0.1 mg/day during folliculogenesis had no adverse effect on ovarian response or clinical results. However, it had no advantage in reducing the HMG dose used for ovulation induction.