Prognostic value of oocyte denudation on fertilization and embryo quality in patients undergoing intracytoplasmic sperm injection

A retrospective analysis of data obtained from 2034 oocytes collected from 157 patients with unexplained infertility was performed. Two groups were planned according to the diameters of flexible polycarbonate pipettes used in denudation. Group 1: Partial denudation of oocytes using a 140µm diameter pipette and Group 2: Complete denudation of oocytes using a 135µm diameter pipette. The data obtained were evaluated using statistical methods. It was aimed to investigate the possible effects of denudation on oocyte maturation, oocyte degeneration rate, fertilization rate, embryo quality, embryo development rate, abortion and live birth rates. After partial and complete denudation, there was no statistically significant difference between Group 1 and Group 2 in terms of oocyte maturation, normal fertilization rate, early embryonal development, embryo transfer numbers, blastocyst stage embryo numbers and morphology. In the third day embryos obtained from Group 2 oocytes, the rate of blastomeres incompatible with the day of development, the rate of degeneration among oocytes and the number of patients whose pregnancies ended due to pathologic reasons were found to be high (p=0.036, p=0.037, p=0.035). Live birth rate was higher in pregnancies developing from group 1 oocytes (p=0.039). It was concluded that granulosa cells left around the oocyte by pipettes with standardized diameter opening during denudation increased the success of live birth.