Purpose: The chance of recurrence of poor fertilization in a second in vitro fertilization (IVF) cycle was assessed.
Methods: Total fertilization failure was defined, and the relationship between the fertilization rate and the number of motile sperm cells per milliliter of semen was assessed. Patients with a total fertilization failure or poor fertilization (20% or less of the oocytes fertilized) were divided into three subgroups with different chances of fertilization and were followed in a subsequent IVF cycle.
Results: The recurrence rate of total fertilization failure was high in all three groups (45-70%), and poor fertilization frequently occurred in the second cycle (50-75%).
Conclusions: Poor fertilization frequently recurs in the second IVF cycle. The use of intracytoplasmic sperm injection could be considered after fertilization of 20% or less of oocytes in the first cycle, irrespective of the number of motile sperm cells per milliliter of semen.