What is ICSI?
The abbreviation ICSI stands for “intracytoplasmic sperm injection”. This means that a single sperm is injected directly into the interior of the cell (cytoplasm) of the previously retrieved egg using a fine pipette. The procedure mimics the natural penetration of the sperm into the egg. However, the entire process takes place outside the body (extracorporeal) and is monitored under a microscope.
How does ICSI work?
Ovulation and egg collection
Semen sample
On the day of egg collection, fresh or processed, frozen sperm must be available – for example from a sperm donation. Based on appearance, shape and motility, the reproductive physician selects a suitable sperm cell for ICSI.
Variant PICSI
Sperm injection and transfer
ICSI: Duration
The entire procedure takes a maximum of 20 days. For a first pregnancy test after ICSI you have to wait about five weeks. If ICSI was successful, you can use special pregnancy calculators to determine the date of birth. Whether ICSI or IVF: the date of egg collection or the day on which a cryopreserved sample was thawed is used as the basis for calculation.
For whom is ICSI suitable?
Reasons for this can be antibodies against sperm, missing vas deferens, blocked seminal ducts or impaired sperm production in the testicles. If there are no sperm cells in the ejaculate (azoospermia), they may be obtained from the testicles or epididymis by surgery (TESE or MESA). ICSI also promises success after cancer therapy, when only frozen (cryopreserved) sperm cells are available.
Chances of success of ICSI
In principle, one egg and one sperm cell are sufficient for ICSI. Therefore, even in men with few sperm in the ejaculate or poor sperm quality, the ICSI success rate is good. Fertilization occurs in more than 70 percent of the eggs.
Assisted Hatching
A new method to improve the chances of success of ICSI (or in vitro fertilization, IVF) is “assisted hatching”. After the egg has been artificially fertilized and the embryo has been created by cell division, it must implant in the uterine lining on about the fifth day. However, this can only succeed if the envelope surrounding the embryo (the so-called zona pellucida) is thin enough for the embryo to hatch out of it.
In some studies, assisted hatching increased the pregnancy rate. However, there are also studies in which no such advantage of laser treatment was demonstrable.
Advantages and disadvantages of ICSI
For the woman, ICSI treatment begins with hormonal stimulation of the ovaries. This can be physically very stressful. In the worst case, an overstimulation syndrome develops, which can become life-threatening. There are also small risks of infection or injury after the puncture of the ovaries – i.e. the removal of the eggs for ICSI.
