Objective To find the possible factors predicting fertilization failure of in vitro fertilization-embryo transfer (IVF-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 ± 2.9 years, 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.
