OOLEMMA CHARACTERISTICS IN RELATION TO SURVIVAL AND FERTILIZATION PATTERNS OF OOCYTES TREATED BY INTRACYTOPLASMIC SPERM INJECTION

The aim of this study was to analyse the various reactions displayed b y the oolemma to the penetrating pipette during intracytoplasmic sperm injection (ICSI) and correlate them with clinical factors, oocyte sur vival and fertilization patterns, Three types of oolemma responses wer e observed: normal breakage, when the injection needle created an inva gination that ruptured at the approximate centre of the egg; sudden br eakage, when the membrane broke without creating a funnel; and difficu lt breakage, when the membrane did not break or broke after several pe netration attempts, A total of 2928 oocytes were analysed with the fol lowing observations: 73.9% (n = 2164) experienced normal breakage, 11. 8% (n = 345) sudden breakage, and 14.3% (n = 419) difficult breakage, The survival rate and number of normally fertilized oocytes were signi ficantly lower and the incidence of digynic oocytes was significantly higher in the sudden breakage group; furthermore, in this group a sign ificantly shorter length of stimulation was observed along with lower serum oestradiol concentrations when compared to oocytes experiencing normal and difficult breakage patterns, These recorded patterns were p redictive of the survival and fertilization ability of the injected oo cytes, as well as the incidence of digyny, The link between membrane b ehaviour and various clinical parameters appears to indicate a correla tion between the modality of stimulation and oolemma characteristics.