THE RESULT OF INTRACYTOPLASMIC SPERM INJECTION IS NOT RELATED TO ANY OF THE 3 BASIC SPERM PARAMETERS

High success rates have been reported for the use of intracytoplasmic sperm injection (ICSI) in alleviating essentially andrological inferti lity, However, neither the relationship between any of the sperm param eters and the result of ICSI nor the minimal sperm requirements for IC SI have been investigated so far. In this paper, our objective was the refore to study the relationship between three basic sperm parameters (total sperm count, sperm motility and morphology) and the outcome of ICSI by retrospective analyses of fertilization, embryo development an d pregnancy rates in 966 micro-injection cycles, performed with ejacul ated semen. The results showed that there was no important influence f rom either the type or the extent of sperm impairment on the outcome o f ICSI. Even in the most extreme cases of male-factor infertility, whe re crypto-zoospermia or total astheno- or total teratozoospermia was d iagnosed in the initial semen sample, high fertilization and pregnancy rates were obtained by ICSI. Only one condition had a strongly negati ve influence on the result of ICSI: where an immotile (presumably dead ) spermatozoon was injected into the oocyte. Thus the only ultimate cr iterion for successful ICSI is the presence of at least one living spe rmatozoon per oocyte in the pellet of the treated semen sample used fo r micro-injection.