When the sperm meets the egg, the first thing to happen is the egg is activated and responds by releasing calcium from internal storage. In some cases, activation of the egg doesn’t occur.
Artificial Oocyte Activation ‘AOA’ can help activate the egg by using a calcium ionophore which causes an increase in calcium in the egg, improving the chance of fertilisation.
When is AOA used?
AOA can be used in a subsequent cycle after a cycle of ICSI results in no or very low fertilisation (less than 30%) and there is no obvious egg factor that can be corrected.
AOA cannot be used for the eggs after they fail to fertilise. No fertilisation after ICSI is rare – fewer than 2% of ICSI cycles. Often no or low fertilisation is due to an egg factor which may not be seen in another ICSI cycle.
Ask your doctor
If you have experienced an ICSI cycle with no or low fertilisation, your doctor will decide if AOA is a suitable option for a subsequent cycle. Please don't hesitate to ask your medical team about AOA.