Chen L, Li D, Ni X, et al. - In the present study, researchers examined how the normal sperm morphology rate affects the clinical and neonatal outcomes of conventional in vitro fertilisation cycles. They performed retrospective analysis of 427 and 2,728 cycles from the normal sperm morphology rate < 4% and ≥ 4% group respectively. They observed significantly higher rate of total fertilization failure in the normal sperm morphology rate < 4% group vs ≥ 4% group (2.8% vs 1.2%). Early rescue intracytoplasmic sperm injection completely resolved total fertilization failure. The two groups were not significantly different regarding the clinical pregnancy, implantation and abortion rates. Observations thus suggest significantly increased total fertilization failure rate in correlation with normal sperm morphology rate < 4% but with no effect on clinical or neonatal outcomes.