The only difference from IVF is in the way the eggs are fertilised. A sperm cell is first immobilised and extracted using an ultrafine needle. This is then introduced into the egg itself.
This technique is recommended if the sperm cells cannot cause fertilisation on their own.
One disadvantage of the technique is possibly the slight increase in the number of congenital disorders in children born after ICSI (+ 0.8% compared with ordinary IVF).
With this technique it will be the biologist who selects the sperm cell to fertilise the egg. In ordinary IVF this takes place by natural selection. There is also the mechanical aspect of piercing the egg. Because of these two elements, it is the centre’s policy to only use ICSI if strictly indicated.