Fertilization and early embryology: Intracytoplasmic sperm injection does not overcome an oocyte defect in previous fertilization failure with conventional in-vitro fertilization and normal spermatozoa

A cohort comprising a total of 447 oocyte aspirations due to male factors (n = 258) or to previous fertilization failure by IVF in the presence of normal sperm parameters (n = 189) was studied. We found a significantly reduced implantation and pregnancy rate per transfer in the group with previously failed IVF attempts compared to the male factor group (P < 0.001). No differences were found in age, number of oocytes retrieved, number of embryos transferred or quality of embryos scored at the time of transfer. However, the fertilization and cleavage rates were found to be reduced in the group with previous failed IVF cycles. It is therefore concluded that previous fertilization failure despite normal sperm parameters in an IVF cycle may not be alleviated by the intracytoplasmic sperm injection (ICSI) procedure. These patients might suffer from oocyte defects as well.