OOLEMMA RUPTURE INSIDE THE INTRACYTOPLASMIC SPERM INJECTION NEEDLE SIGNIFICANTLY IMPROVES THE FERTILIZATION RATE AND REDUCES OOCYTE DAMAGE

Objective: To compare the effect on fertilization, oocyte damage, embr yo freezing, and pregnancy rates of two different techniques for ruptu ring the oolemma during intracytoplasmic sperm injection (ICSI). Desig n: Retrospective study. Setting: Fertility Center, Alliant Health Syst em Hospital. Patient(s): Seventy-nine consecutive IVF-ICSI cases. Inte rvention(s): Patients in group I had ICSI performed by pushing the nee dle into the oocyte until the oolemma was observed to break outside th e needle. In group II the oolemma was aspirated into the needle until it ruptured inside the needle. Main Outcome Measure(s): In group II IC SI resulted in significantly higher fertilization and lower oocyte dam age rates (66% and 13%) than in group I (39% and 29%). There were no s tatistically significant differences in embryo cleavage rates or pregn ancy rates per retrieval between the two groups. A greater number of c ases had embryos cryopreserved in group II than in group I. Result(s): Rupturing the oolemma by aspirating it into the ICSI needle (group II ) improved laboratory outcomes compared with the more traditional tech nique of breaking this membrane by the stabbing action of the needle ( group I). This modification of the ICSI technique also increased the n umber of patients with cryopreserved embryos and therefore could incre ase the pregnancy rate per patient. Conclusion(s): The site and techni que used to rupture the oolemma during ICSI has a significant effect o n the fertilization and damage rates. (Fertil Steril(R) 1998;70:676-9. (C) 1998 by American Society for Reproductive Medicine.).