A detailed semen analysis helps us to select the most suitable method of egg fertilization. 
Two different methods can be used for fertilization – the classic IVF method or the ICSI method (intracytoplasmic sperm injection).
In Vitro Fertilization 
The classic fertilization method is carried out when the semen analysis shows standard parameters and the IBT asseses the presence of antisperm antibodies. In vitro fertilization takes place after adding sperm concentration into special fertilization medium containg oocytes and it is followed by their fusion – this is so-called ” spontanous fertilization in a test tube.”
ICSI (Intracytoplasmic Sperm Injection)
The ICSI method is used when the semen analysis parameters are not satisfying, the number of retrieved oocyt is low, their quality is not good, the infertility is caused by immunological factors or in the case of patients whose embryos have to be tested by PCR/aCGH method.
ICSI is a micromanipulative technique in which the embryologist injects sperm into an oocyte by micro pipette. The procedure is done under a microscope using a micromanipulator.
A micromanipulator is a device for procedures where a level of precision of movement is necessary that cannot be achieved by the unaided human hand. A part of the device is a holding pipette that stabilizes the mature oocyte and a narrower ICSI micropipette is used to collect a single sperm that fulfills all the important parameters and is then released into the mature egg.
Prior to  the ICSI procedure sperm can be selected on the basis of their functional properties using the PICSI methodMACS method or combination of both of them, or the IMSI method using a very detailed examination of sperm under a microscope.