Prospective randomized controlled trial in GnRH antagonist stimulated cycles comparing hcg triggering alone versus hcg triggering associated with GnRH agonist

The detection of differences in the number of metaphase II oocytes after triggering with HCG versus triggering with the combination of HCG and GnRH agonist. A prospective randomized trial was performed comparing two study groups of ICSI patients. A total of 120 patients were included. In group one (n=61), patients were stimulated with recombinant FSH and GnRH antagonist, final oocyte maturation was triggered with HCG. In group 2 (n=59), triggering was performed with HCG and GnRH-agonist, Triptoreline 0.2 mg. Recombinant FSH stimulation started at day 2 of the cycle with a standard dose of 200 IU. GnRH antagonist was associated from day 6 onwards on a daily basis. Triggering took place as soon as 3 follicles of 17 mm. In the first group triggering was performed with 5000 IU of HCG; in the second group HCG 5000 IU was combined with 0.2 mg GnRH-agonist. The number of MII oocytes was the primary endpoint. The secondary endpoints were embryo morphology, number of cryo-embryos and pregnancy rate. The statistical tests used: t-test, X2 or Fisher Exact test, linear regression model; two-sided at 5% significance. The mean number of MII oocytes in the HCG triggered group was 9.2 in comparison to 10.3 in the HCG-GnRH agonist group (p=0.3). In group I, only 21/61 (34,4%) of the patients did have frozen embryos, whereas in group II 33/59 (55.9%) had embryos frozen (p=0.046). In group II significantly more embryos were of excellent morphological quality 45/59 (83%)(p=0.001). In group I only 28/61 (45.9%) were of excellent morphological quality. Ongoing pregnancy rates per started cycle in group I and II were 26 (42.6 %) and 19 (32.2%) respectively. No significant differences in mean number of MII oocytes were detected. Embryo morphology was significantly improved after the combined simultaneous triggering with HCG and GnRH agonist and also significantly more embryos could be cryopreserved.