Reinsemination by intracytoplasmic sperm injection of 1-day-old oocytes after complete conventional fertilization failure

Abstract

Objective: To analyze the efficacy of intracytoplasmic sperm injection (ICSI) for “rescue” of failed conventional insemination cycles. Design: Retrospective clinical study. Setting: Private infertility clinic. Patient(s): Fifty-four couples with non-male factor infertility undergoing routine IVF within our clinic. Intervention(s): Twenty- to 24-hour-old unfertilized mature oocytes from conventional IVF cycles in which fertilization failure was complete were reinseminated by ICSI to attempt late fertilization and rescue of the otherwise failed IVF cycle. Main Outcome Measure(s): Late fertilization, pregnancy, and embryonic implantation. Result(s): Intracytoplasmic sperm injection reinsemination of 489 unfertilized mature oocytes caused degeneration in 50 (10.2%) oocytes, gave rise to normal fertilization in 215 (44.0%) of the injected oocytes, and allowed ET in 48 of the 54 cycles in which initial complete fertilization failure had occurred. One hundred sixty-four (76.3%) of 215 late-fertilized oocytes either were used for fresh transfer or were frozen-stored. Eight viable pregnancies resulted, yielding a 14.8% pregnancy rate per initiated cycle. Conclusion(s): Barring potential concerns regarding the chromosomal normality of embryos arising from reinsemination, our results suggest that ICSI is a relatively successful means of rescuing conventional IVF cycles in which fertilization fails completely.