Defective oocytes: a new subgroup of unexplained infertility.

OBJECTIVE

To define a new category of unexplained infertility and its potential treatment.

DESIGN

Normal infertile couples underwent prospectively, cross-fertilization attempts in which the wife's oocytes were inseminated by the husband and donor semen. After recurrent failure of fertilization, cross insemination of donor oocytes was attempted with the husband sperm.

SETTING

In vitro fertilization unit at a teaching hospital.

PATIENTS

Three couples who were diagnosed as suffering of unexplained infertility and treated by in vitro fertilization (IVF).

RESULTS

The female partner of these couples produced morphologically normal oocytes that were demonstrated to be functionally defective and failed to fertilize in vitro with both husband and donor sperm. Donated oocytes inseminated by the husband's sperm were fertilized in all patients, demonstrating the normal fertilizing ability of the husbands' semen. One patient conceived and delivered after an oocyte donation.

CONCLUSIONS

Conclusive diagnosis of defective oocytes as a cause of infertility may be made only after IVF and oocyte donation.