FAILURE OF OOCYTE ACTIVATION AFTER INTRACYTOPLASMIC SPERM INJECTION USING ROUND-HEADED SPERM

Objective: To examine the outcome of intracytoplasmic sperm injection (ICSI) with round-headed sperm (globozoospermia). Design: Retrospectiv e analysis. Setting: In vitro fertilization laboratory with extensive ICSI experience. Patient(s): A patient couple with infertility because of globozoospermia seeking ICSI treatment. Main Outcome Measure(s): F ertilization, cleavage, and pregnancy rates. Intervention(s): Intracyt oplasmic sperm injection and calcium ionophore. Result(s): This couple experienced only 7% fertilization after ICSI in their first cycle. Tr eatment of the unfertilized oocytes with calcium ionophore 20 hours af ter ICSI-induced fertilization and cleavage of 79% of the oocytes. Emb ryo quality was fair to good. On the second cycle, 8 of the injected o ocytes were treated with ionophore immediately after ICSI and the rema ining 20 oocytes were untreated. Normal fertilization was achieved in 75% of the treated and 10% of the untreated oocytes. Treatment of thes e unfertilized oocytes with ionophore 20 hours after ICSI resulted in fertilization in 73%. Pregnancy was not achieved after either ICSI cyc le. Ultrastructural analysis indicated multiple structural abnormaliti es in the sperm. Conclusion(s): These results indicate that the round- headed sperm from this patient were incapable of oocyte activation aft er ICSI. This may be the reason for the frequent ICSI fertilization fa ilure seen with this condition. Current ICSI procedures may not always overcome the infertility associated with globozoospermia, and further study of the etiology of this condition is needed. (C) 1997 by Americ an Society for Reproductive Medicine.