Natural conception following total fertilization failure with intracytoplasmic sperm injection in a couple with unexplained infertility: a case report.

With the introduction of intracytoplasmic sperm injection (ICSI), couples with severe male factor infertility have been able to achieve fertilization and clinical pregnancy rates comparable to other in vitro fertilization patients. However, despite the utilization of microsurgical sperm injection techniques, failure of fertilization still occurs in a few patients. How such fertilization failure after ICSI might impact later ICSI treatments is less understood.