Background: The use of GnRH analogue medication is essential in reproductive medicine to
avoid premature ovulation by pituitary suppression for the duration of ovarian stimulation by gonadotrophins.
The type of pituitary suppression by either GnRH agonist analogues versus GnRH antagonist
analogues may result in different embryological hence clinical results. Preimplantation genetic
diagnosis is a subtype of IVF in which embryos are created for genetic diagnosis of hereditary disorders
in order to avoid genetically affected children. Embryological quality hence ovarian stimulation in
preimplantation genetic diagnosis is crucial as genetic selection will reduce the number of available
embryos to a fraction of the total.
Objective: The aim of this study was to assess the efficiency of GnRH antagonist versus GnRH agonist
treatment for pituitary suppression in ovarian stimulation for PGD, by proxy of number and quality of
embryos at cleavage stage available for biopsy.
Method: We conducted a prospective randomised controlled trial comparing pituitary suppression by
GnRH antagonist versus GnRH agonist in ovarian stimulation for PGD. The primary outcome measure
was the number of embryos of sufficient quality for biopsy at cleavage stage. Secondary outcome parameters
were the number of blastocysts available of top quality, and clinical pregnancy rate.
Results: There was no difference in number of oocytes retrieved, embryos at cleavage stage available
for biopsy or embryo quality. The clinical pregnancy rate was higher in the GnRH agonist group; however
the sample size was insufficient to allow conclusions.
Conclusion: The use of GnRH agonist versus antagonist treatment does not result in differences in a number
of oocytes, embryos or embryo quality in ovarian stimulation for preimplantation genetic diagnosis.