Total fertilization failure in intra-cytoplasmic sperm injection cycles--classification and management

In this retrospective cohort study we intended to propose a classification and preliminary management strategy for couples exhibiting total fertilization failure (TFF) in intra-cytoplasmic sperm injection (ICSI) cycles. Sixteen couples with a total of 27 cycles exhibiting TFF, age <40 and/or more than four M2 oocytes aspirated were enrolled. While TFF occurred in 4.3% of all 3723 ICSI cycles, in women younger than 40 with at least 5 M2 oocytes the TFF rate was 0.7%. Indications for ICSI were severe male factor and unexplained infertility. Of the 16 couples with TFF, 4 demonstrated a single episode of TFF, with either subsequent or former normal fertilizations, thus implying possible sporadic faulty laboratory conditions. Ten couples demonstrated repeated total or very low fertilization rates, hinting at a gamete defect not overcome by ICSI. Two couples experienced TFF in the first and only cycle performed at our unit. We conclude that initial and repeated TFF hints at severe gamete defects for which only donor gametes may prove successful while sporadic TFF events could simply imply a technical modifiable condition.