【Objective】 To analyze the clinical factors leading to total fertilization failure (TFF) after in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). 【Methods】 All couples who underwent IVF (5778)

half-ICSI (146)

ICSI (821)

and PESA-ICSI (274) between January 2007 and May 2011 in our center were involved in the study. Data were analyzed by ?字2 test

multivariate logistic regression or student?蒺s t-test. Some MII oocytes of TFF in group ICSI were detected by confocal microscopy coupling with immunofluorescence. 【Results】 The TFF rates in group IVF and ICSI were 2.1% and 2.3%

respectively (P > 0.05)

while it was 21.9% for those undergoing IVF in group half-ICSI (P < 0.01). The TFF rates were higher if oocyte yield was poor (≤3) in all groups except group half-ICSI (P < 0.01)

asthenozoospermia and oligozoospermia were both high risk factors leading to TFF (P < 0.05)

but TFF with ICSI could not be predicted by teratozoospermia and TFF in a previous IVF cycle (P > 0.05). 【Conclusion】Low oocyte yield is disadvantageous for fertilization in either IVF or ICSI cycle

it is the key for success to get proper number of oocytes in an ART cycle. There is no impact for teratozoospermia on the fertilization rates in IVF or ICSI cycle. For coulpes with TFF in a previous IVF cycle

ICSI will be the first choice.