Step 5: Embryo Selection and Transfer

Embryo quality is a critical factor affecting the success of IVF. The best embryos are transferred to the uterus based on grade and cell number. In some instances, assisted hatching is used to increase pregnancy and implantation rates by enhancing the embryo's ability to escape from the zona pellucida at the blastocyst stage.

Embryos are transferred into the uterus through a small tube or catheter. This procedure does not require anesthesia, as it is usually painless. The embryos are placed in a small amount of fluid inside the catheter, which is threaded through the cervix during a speculum examination.

The embryos are implanted so that they reach the top part of the uterus. Abdominal ultrasound is used to confirm the correct placement. Depending on the patient's wishes and age, one to five embryos may be transferred in one treatment cycle.