treatment strategy changed

The use of antagonist controlled ovarian stimulation protocols has allowed the use of GnRH agonist to be used for final oocyte maturation. The use of GnRH agonist as ovulation trigger has been shown to reduce the risks for ovarian hyperstimulation syndrome (OHSS), but its sole use results in reduced embryo implantation due to luteal phase insufficiency. The combination of GnRH agonist and variable doses of hCG for final oocyte maturation has been shown to overcome the luteal phase insufficiency effecting endometrial receptivity.

In this study the investigators will test the hypothesis that using GnRH agonist (0.2mg Triptorelin) and a full dose of hCG (6500IU Ovitrelle) for final oocyte maturation in normoresponders will increase oocyte maturity, embryo quality and embryo implantation and reduce ovarian hyperstimulation syndrome, as compared to the traditional hCG (full dose) alone trigger.

Inclusion Criteria:

• Age; < 40 years
• Cycle number; cycles 1 or 2
• Antral follicle count; >10 and <25
• BMI; >18 and <30
• Normogonadotrophic cycle length; 24 to 25 days
• Male; ejaculated semen only

Exclusion Criteria:

• Presence of endocrine disorders; (diabetes mellitus, hyperprolactinemia, thyroid dysfunction, congenital adrenal hyperplasia, Cushing syndrome, or polycystic ovary syndrome)
• Previous major uterine surgery (that would affect endometrial receptivity)

Secondary exclusion criteria

• <5 follicles at the time of trigger
• <2 full formed blastocyst on day 5 of embryo culture