The study looked at factors that may predict fertilization failure in IVF patients. They compared 32 patients with complete fertilization failure to 56 matched controls. Patients with longer infertility duration, more superovulation days, primary infertility, higher progesterone levels, and severe abnormal sperm were more likely to experience fertilization failure. Patients with primary infertility, longer infertility duration, more superovulation days, higher progesterone levels, and a high rate of abnormal sperm are at higher risk of fertilization failure.