The effect of the dose of human chorionic gonadotropin and the type of gonadotropin stimulation on oocyte recovery rates in an in vitro fertilization program.

The effect of the dose of human chorionic gonadotropin (hCG) on oocyte retrieval in an in vitro fertilization (IVF) program was studied. Following ovulation induction using clomiphene citrate and either pure follicle-stimulating hormone (FSH) or human menopausal gonadotropin (hMG), hCG was administered at a dose of 2000 IU (n = 88), 5000 IU (n = 110), and 10,000 IU (n = 104). There was a significantly lower successful oocyte recovery in patients who received 2000 IU of hCG (77.3%) compared with patients who received either 5000 IU of hCG (95.5%) or 10,000 IU of hCG (98.1%; P less than 0.001). There was no significant difference between 5000 or 10,000 IU of hCG. In patients who received 2000 IU of hCG, successful oocyte recovery was significantly lower when pure FSH was used (60%) compared with those who received hMG (84.1%; P less than 0.03). Patients have different thresholds for follicular response to hCG and the recommended minimum dose of hCG should be at least 5000 IU.