This technique is considered as the least intrusive for the normal fertilization of the egg by the sperm. Following the collection process, the eggs are placed together with the sperm under special conditions, similar to the ones in the body of a woman, so that the most suitable sperm is able to fertilize the egg within a few hours.
This process is characterized as the least intrusive one, since the post “capable-healthy” sperm is the one that will fertilize the egg and not another accidental sperm, which may not be ideal for fertilization purposes.
In other words, the ovum is indirectly capable of screening and selecting the fittest sper, a fact that will secure its subsequent development into a fetus.
However, the conventional IVF depends on the quality of sperm. What is evaluated is the mobility, the number and morphology of spermatozoa. If any of these parameters is affected, then one will ultimately need to resort to the ICSI method.