Received November 16, 2013
Accepted November 16, 2013

OBJECTIVE: To compare the level of serum HCG 12 hours after application of 10,000 IU hCG intramuscular in patients with GnRH agonists versus GnRH antagonists in ICSI cycle and its impact on the proportion of pregnancy. MATERIALS AND METHODS: A retrospective, observational study at the Mexican Institute of Infertility. Patients were included in ICSI cycle 2010-2012. The stimulation was performed with r-FSH and menotropins, alone or in combination with clomiphene citrate. They were divided into two groups according to the use of GnRH agonist or antagonist. Blood samples were taken for determination of basal serum FSH, estradiol, progesterone and LH on day of HCG administration and a determination of HCG 12 hours after intramuscular administration day in which at least two or more follicles had 18mm. In both groups, patients were excluded with serum progesterone levels > application 2ng/ml day of hCG. STATISTICAL ANALYSIS: We realized t student and considered significant p-value <0.05. RESULTS: There were 199 patients total. Agonists in the group n = 35 and n = 164 in the GnRH (n). The average level of basal FSH was 6.6 (GnRHa) and 6.5mUI/mL (GnRHan) (p>0.05). Average levels of HCG levels were 239 vs 262mUI/mL (p>0.05). The fertilization rate was 72% vs 65% (p >0.05) (Table 1). Conclusion: There were no significant difference in serum levels of HCG for groups, or pregnancy rate.