Objective To find the possible factors predicting fertilization failure of in vitro fertilization-embryo transfer （1VF-ET）. Methods The IVF-ET patients with complete fertilization failure （experimental group, n =32） were analyzed retrospectively. The patients whose oocytes retrieved at the same day and cultured on the same incubators with ≥ 50% fertilization rates were matched as the control （n=56）. Results The infertility duration, superovulation days, the rates of primary case, progesterone （P） level 〉3.12 nmol/L rate and rate of severe abnormal sperm （abnormal sperm rate 〉95%） in experimental group were significantly higher than those in the control （6.4 ±3.1 years, 12.6 ±2.2 d, 56%, 43%, 43% vs 4.6±2.9years, 11.6 ±% 1.3 d, 33%, 23%, 23%, respectively, P〈0.05）. Conclusion We should pay attention to these patients with primary infertility, longer infertility duration and superovulation days （〉6.4 years and 〉12.6 d） and having increased level of P on hCG injection day （〉3.12 nmol/L）, abnormal sperm rate 〉95% at the same time. They should be included in such patients at high risk of fertilization failure.
