IVF fertilization takes place in vitro i.e. outside the body. Fertilization takes place in an incubated Petri dish.
The resulting embryo is transferred back to the uterus on Day 3 at the 6-8 cell stage.
Sometimes the embryo transfer is done at the blastocyst stage on Day 5. The embryo is drawn into a specialized catheter along with a small amount of culture medium and is transferred into the uterus.
