Reinsemination of one-day-old oocytes by use of intracytoplasmic sperm injection.

OBJECTIVE

To evaluate the possible advantages of reinseminating oocytes by use of intracytoplasmic sperm injection (ICSI).

DESIGN

Clinical study.

SETTING

In vitro fertilization unit with research facilities.

PATIENTS: Fifty-seven couples who were part of our regular IVF program.

INTERVENTIONS: Nonfertilized oocytes from IVF cycles with no or very low fertilization were microinjected with spermatozoa approximately 25 hours after oocyte pick-up.

MAIN OUTCOME MEASURES: Fertilization and pregnancy rates.

RESULTS

A mean fertilization rate of 46.5% was obtained when reinseminating the oocytes on day 2 using the ICSI procedure. Of 57 cycles with completely or almost completely failed fertilization, 29 patients received ET after reinsemination by ICSI. Two of these transfers resulted in pregnancies (6.9% per ET) and two healthy babies were born.

CONCLUSION

Despite this relative success, considering both the extra work involved and the potential genetic risk, it is doubtful whether ICSI on day 2 should be recommended as a routine procedure. For training and research purposes, however, this approach can be of value.