Abstract
A total of 1,923 follicular human ova were collected for use in intracytoplasmic sperm injection (ICSI). Timed ovulation was induced by means of a standard ovarian stimulation protocol involving set dosages of follicle stimulating hormone (FSH), human menopausal gonadotrophin (HMG) and human chorionic gonadotrophin (hCG). Prior to performing ICSI, all of the ova were subjected to thorough examination which led to the discovery of only two parthenogenetic oocytes, also referred to as parthenogens, out of the total 1,923. These oocytes were retrieved from different patients. Although genetic analysis revealed that one of the parthenogens had a haploid number of chromosomes, it was impossible to analyze the second because it had not yet reached the metaphase stage. The 0.1 percent incidence of spontaneous parthenogenesis in this study clearly indicates that this phenomenon is extremely rare.