Comparison between two hCG-to-oocyte aspiration intervals on the outcome of in vitro fertilization

PURPOSE: To determine whether there was any difference in the outcome of in vitro fertilization when retrieval of oocytes was done 34 hr (group A) or 38 hr (group B) after hCG injection. METHODS: A total of 170 patients with tubal failure were randomized into either group A (83 patients) or group B (87 patients). They underwent in vitro fertilization according to described protocols and were compared with regard to the frequency of spontaneous ovulation, number of oocytes retrieved, oocyte cumulus complex quality, embryo quality, and implantation and pregnancy rates. RESULTS: There was no significant difference for any of the parameters tested for in group A and group B. CONCLUSIONS: HCG can be administered at any time within the time interval of 34 to 38 hr before retrieval of oocytes without affecting the results of in vitro fertilization.