NORMAL FERTILIZATION AND EMBRYO DEVELOPMENT BY INTRACYTOPLASMIC SPERMINJECTION OF ROUND-HEADED ACROSOMELESS SPERM

Objective: To investigate the ability of round-headed acrosomeless spe rm to bind to the human zona pellucida (ZP) and oolemma and to fertili ze human oocytes by intracytoplasmic sperm injection. Design: Oocytes that had failed to fertilize in IVF were used for sperm-ZP and spermoo lemma 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 reprod uctive research laboratory and tertiary referral IVF program. Patients : Case study of a couple in which the man has 100% round-headed acroso meless sperm in the ejaculate. Main Outcome Measure: Fertilization and embryo development and the ability of sperm to bind to the ZP and ool emma. Results: No ZP or oolemma binding was achieved, but normal ferti lization and embryo development was obtained after intracytoplasmic in jection of round-headed acrosomeless sperm. However, no pregnancy was achieved after the transfer of two cleaving embryos. Conclusions: Norm al 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.