Embryological indicators in cycles with HCG or different doses of GnRH-a for the final oocyte maturation in IVF-ICSI patients

Abstract

Application of gonadotropin-releasing hormone agonists (GnRH-a) as a trigger for final oocyte maturation in cycles of in vitro fertilization (IVF) substantially decreases the risk of ovarian hyperstimulation syndrome (OHSS). So far there is no consensus on the optimal dosage of GnRH-a when using it as a trigger in IVF cycles. We compared embryological characteristics in IVF-ICSI cycles when applying triptorelin at a dose of 0,2 mg (test group 2), 0,5 mg (test group 3) and human chorionic gonadotropin (HCG) at a dose of 10,000 IU (test group 1). In group 1, the average number of oocytes per oocyte retrieval (11,7±4,8) was lower in comparison with groups 2 and 3, which can be explained by the differences in the selection of the patients’. The number of oocytes per retrieval in group 3 (20,2±6,3) was significantly higher (p=0.02) compared to group 2 (17,0±6,2). The percentage of mature oocytes (MII) and fertilization rate did not differ between the groups. The rate of blastocyst formation in group 3 (71,9±17,1%) was significantly higher (p=0.02) in comparison with group 2 (57,9±24%). We did not found any significant difference in the rate of embryo implantation in cycles with oocyte donation when HCG or various doses of triptorelin were used as a trigger. We conclude that application of triptorelin at a dose of 0,5 mg may be more effective for triggering final oocyte maturation in IVF cycles in comparison with the dose of 0,2 mg, due to the increase in the number of retrieved oocytes and the improved rate of the blastocyst formation.