J Tesarik1, M Sousa. 1. American Hospital of Paris, Neuilly sur Seine, France.
Abstract
OBJECTIVE: To analyze the mechanism by which modifications of the intracytoplasmic sperm injection (ICSI) technique influence success rates. DESIGN: Prospective clinical study supplemented with an experimental analysis of Ca2+ fluxes provoked by the injection procedure. SETTING: Private hospital and public research center. PATIENTS: Patients treated by IVF and ICSI. INTERVENTIONS:Intracytoplasmic sperm injection. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates and intracellular free Ca2+ concentration. RESULTS: The inclusion of vigorous aspiration of oocyte cytoplasm improved outcomes of ICSI. In a series of 100 consecutive cases treated with this technique, the fertilization and pregnancy rates were 87% of total metaphase II oocytes injected and 52% of total treatment cycles, respectively. Enhanced Ca2+ influx into the injected oocytes and dislocation of the oocyte cytoplasm, including the development of a focus of persistent Ca2+ discharge around the injected sperm head, were the main characteristics of this highly successful technique. CONCLUSIONS: Vigorous aspiration of oocyte cytoplasm may facilitate fertilization after ICSI by increasing the oocyte Ca2+ load at the time of injection, by establishing a more intimate contact of the injected sperm head with oocyte intracellular Ca2+ stores, or by a conjunction of these mechanisms.
RCT Entities:
OBJECTIVE: To analyze the mechanism by which modifications of the intracytoplasmic sperm injection (ICSI) technique influence success rates. DESIGN: Prospective clinical study supplemented with an experimental analysis of Ca2+ fluxes provoked by the injection procedure. SETTING: Private hospital and public research center. PATIENTS: Patients treated by IVF and ICSI. INTERVENTIONS: Intracytoplasmic sperm injection. MAIN OUTCOME MEASURES: Fertilization and pregnancy rates and intracellular free Ca2+ concentration. RESULTS: The inclusion of vigorous aspiration of oocyte cytoplasm improved outcomes of ICSI. In a series of 100 consecutive cases treated with this technique, the fertilization and pregnancy rates were 87% of total metaphase II oocytes injected and 52% of total treatment cycles, respectively. Enhanced Ca2+ influx into the injected oocytes and dislocation of the oocyte cytoplasm, including the development of a focus of persistent Ca2+ discharge around the injected sperm head, were the main characteristics of this highly successful technique. CONCLUSIONS: Vigorous aspiration of oocyte cytoplasm may facilitate fertilization after ICSI by increasing the oocyte Ca2+ load at the time of injection, by establishing a more intimate contact of the injected sperm head with oocyte intracellular Ca2+ stores, or by a conjunction of these mechanisms.
Authors: K Yamanaka; N V Sofikitis; I Miyagawa; Y Yamamoto; T Toda; S Antypas; D Dimitriadis; M Takenaka; K Taniguchi; K Takahashi; S Tsukamoto; H Kawamura; M Neil Journal: J Assist Reprod Genet Date: 1997-01 Impact factor: 3.412