Comparison of IVF outcome in an oocyte donation program using triptorelin or rhCG as trigger oocyte

Authors: Marco Melo, Cristiano E. Busso, José Bellver, Pilar Alama, Nicolas Garriso, Marcos Meseguer, Antonio Pellicer, José Remohí

(Reproductive BioMedicine Online 2009; 19(4): 486-492)

The use of GnRH agonists for triggering ovulation is still a controversy. Few reports are available on this issue. The primary objective was to evaluate the clinical outcome associated with GnRH agonist in comparison to rhCG to trigger final oocyte maturation. Secondly, to compare the embryo quality and ovarian hyperstimulation syndrome (OHSS) incidence between the two regimens.

We analysed the cycle characteristics of 100 oocyte donors undergoing controlled ovarian hyperstimulation (COS), inducing their ovulation with GnRH antagonist and their 100 oocyte recipients. Donors were prospectively randomized on the last COS day in two groups: Group I- single bolus of 0.2 mg of triptorelin or Group II- 250 µg of rhCG.

No differences were observed in the number of oocytes retrieved and in the proportion of metaphase II oocytes between the groups. Higher OHSS rate was found in donors that received rhCG (P = 0.007). Moreover, fertilisation and cleavage rates, embryo quality and number of embryos transferred were similar between the two groups. Finally, there was no significant difference regarding implantation, clinical pregnancy, multiple pregnancy and miscarriage rates between both groups.

In conclusion, GnRH agonist effectively triggers the final oocyte maturation in oocyte donors without damage in the implantation, pregnancy and miscarriage rates. Moreover, this regimen effectively eliminated the risk of OHSS.

KEYWORDS: GnRH agonist, GnRH antagonist, implantation, IVF outcome, oocyte donation, rhCG.