Oocyte aspiration

During oocyte retrieval, the follicle fluid is aspirated from the follicles and examined in the laboratory for eggs. At the time the egg is inside a cloud of cells called granulosa cells. Granulosa cells support oocyte maturation and development inside the follicle. After a couple of hours the oocyte is mature enough to be fertilized.

When performing IVF, the laboratory staff adds sperm to the oocyte at 12 o'clock, after which the spermatozoa themselves must find their way through the zona pellucida into the oocyte and fertilize it. The fertilization process itself is normal. It does not just take place in the fallopian tube but in the incubator, which mimics the conditions inside the body. Two hours later, the embryologist controls that the cloud of support cells are collapsed. It is a sign that fertilization has occurred and surplus sperm are removed from the eggs.

When performing ICSI (micro-insemination), the procedure is done shortly after 12 o'clock. The embryologist looks for a sperm with normal morphology and progressive forward motility and catches a sperm with a very thin glass tube called a pipette. She sucks the sperm into the pipette and then gently places the sperm inside the egg. In this way we have sought to optimize the possibility that fertilization can take place.

However, the fertilization process is a complex biochemical process by which egg and sperm chromosomes must be paired. Therefore, it is not certain that all eggs can be fertilized properly, although the sperm entered the egg. Press the video link if you want to see how ICSI is performed.