Analysis of eggs after failed fertilization using ICSI showed that more than half of the failures occurred due to oocyte activation failure. Oocyte activation is an early event in fertilization. It is caused by material in the sperm that is thought to induce calcium release from the endoplasmic reticulum and also from other structures of the oocyte. Various chemical substances have been identified that can induce calcium increase and oocyte activation during in vitro fertilization, such as calcium ionophore. Egg activation using calcium ionophores may be effective at improving fertilization rates in ICSI cycles where the egg and sperm have failed to activate in previous treatment cycles. Egg activation theoretically could cause embryos to have abnormal numbers of chromosomes, which would cause the pregnancy to miscarry. Currently, there is not enough evidence to decide whether these risks are a serious concern, but the use of calcium ionophore is still constrained to cases of repeat IVF cycles.
Sperm Mapping
In some men with non-obstructive azoospermia, there is a small amount of sperm production. However, it is difficult to find and extract it due