Normal fertilization and embryo development by intracytoplasmic sperm injection of round-headed acrosomeless sperm.

OBJECTIVE

To investigate the ability of round-headed acrosomeless sperm to bind to the human zona pellucida (ZP) and oolemma and to fertilize human oocytes by intracytoplasmic sperm injection.

DESIGN

Oocytes that had failed to fertilize in IVF were used for sperm-ZP and spermoolemma binding tests. Sperm from a fertile donor was used as a control for oocyte variability. Intracytoplasmic sperm injection was used for assisted fertilization.

SETTING

University- and hospital-based reproductive research laboratory and tertiary referral IVF program.

PATIENTS

Case study of a couple in which the man has 100% round-headed acrosomeless sperm in the ejaculate.

MAIN OUTCOME MEASURE

Fertilization and embryo development and the ability of sperm to bind to the ZP and oolemma.

RESULTS

No ZP or oolemma binding was achieved, but normal fertilization and embryo development was obtained after intracytoplasmic injection of round-headed acrosomeless sperm. However, no pregnancy was achieved after the transfer of two cleaving embryos.

CONCLUSIONS

Normal fertilization and embryo development from round-headed acrosomeless sperm is possible with intracytoplasmic sperm injection. However, it remains to be reported whether pregnancy can result from fertilization with this type of sperm defect.