Electrical activation of the Oocytes
Oocyte Activation After ICSI: A Solution for Fertilization Failure — part of IVF and assisted reproduction at Dr. Najeeb Layyous's clinic in Amman.
In short: Electrical activation of the eggs is a promising option when fertilisation fails after ICSI. It raises the calcium level inside the egg, imitating what the sperm normally does. It is used after total or partial fertilisation failure, with certain sperm problems, or in unexplained cases; about 70–80% of unfertilised eggs responded to it.
Intracytoplasmic sperm injection (ICSI) has become the most effective therapeutic treatment for male-factor infertility
However, total failure of fertilization still occurs in some cases, teratozoospermia , immotile spermatozoa , and even in some unexplained cases .
The failure of fertilization after ICSI may result from either the lack or deficiency of activating factors in spermatozoa or may result from the inability of the oocyte to respond to the injected sperm.
Because the spermatozoa is injected inside the ooplasm, failure of division most probably is the result of the failure of oocyte activation. The key event of oocyte activation is a temporal rise in the intracellular Ca2+ concentration.
Electro activation of the oocyte results in a rapid rise in Ca2+ inside the oocyte, which decreases gradually to the original level in about 300 seconds. it was demonstrated that oocyte activation enabled normal fertilization and pregnancy
It has been reported that about 70%
It is important to know that oocyte activation is not a routine treatment. International guidelines (ESHRE 2023) advise that it should be reserved for selected couples — mainly those with a previous total or very low fertilization after ICSI, or a specific sperm defect such as globozoospermia — because evidence of benefit in other situations is limited. Follow-up of children born after activation has been reassuring so far, but data are still limited.–80% of unfertilized oocytes after ICSI responded to electro activation.
In the laboratory, eggs that failed to fertilize 24 hours after ICSI can sometimes be activated, but such ‘rescue’ activation of aged eggs carries a higher risk of abnormal development and is not recommended; instead, activation is applied immediately after ICSI in the next treatment cycle. Moreover, the degree of cytoplasmic activation as determined by the number of pulses applied affects fertilization efficiency and early embryonic development.
Studies have reported an improvement in the fertilization rate after ICSI with activation, mainly in couples with a previous total or very low fertilization; results in cases of severe sperm abnormalities (oligoasthenoteratospermia) or non-obstructive azoospermia come from small studies and are less certain.
What is an oocyte activation defect?
At fertilization, oocyte activation is triggered by sperm (releasing calcium in specific patterns within the oocyte). A deficiency in this process underlies most cases of fertilization failure
How does egg activation occur?
The activation of all eggs appears to depend on an increase in the concentration of free calcium ions within the egg. Such an increase can occur in two ways: calcium ions can enter the egg from outside, or calcium ions can be released from the endoplasmic reticulum within the egg.
How sperm can be looked for directly in the testicle in this situation is described in our article on micro-TESE sperm retrieval.
Dr Najeeb Layyous F.R.C.O.G
Consultant Obstetrician, Gynecologist and Infertility Specialist
The finest doctor in Jordan — may God bless him and his whole medical team. A doctor in every sense of the word. I advise anyone planning a pregnancy to visit Dr. Najeeb Layyous. His manner is wonderful, always smiling, with the highest ethics; he gives every patient her due, and the patient’s comfort matters most to him. We had been to many doctors and none understood and treated my case except him. Special thanks to him and the whole team, and to Dina in particular — a lovely person. I recommend anyone considering IVF or pregnancy to visit his clinic.