The follicular fluid released from the ovaries is transported to the laboratory for a number of different uses:
- Detecting eggs in the follicular fluid and transferring them to a growth platform
- Sperm enhancement
- The insemination process
Insemination is the encounter between the sperm and the egg. This process in a petri dish which contains 3-4 oocytes and about 100-300 thousand sperm cells per plate. The plates are held in an incubator at 37ºC. Each patient has a designated cell in the incubator, and all the dishes are marked for identification.
Tests for egg fertilization are performed in the laboratory:
- Normal fertilization
- Abnormal fertilization
- Lack of signs of fertilization. In these cases it is sometimes possible to perform repeated insemination.
48-72 hours after the puncture, tests are performed to check the quality of the embryos and they are either returned to the uterus, or alternatively frozen. There is a direct relationship between the quality of the embryos and their ability to implant leading to a normal pregnancy. The number of embryos returned are determined on the day of return taking into account the patient's age, medical history and the quality of the embryos. The remaining embryos will be frozen for later use or be raised to the blastocyst stage for return at a later time.
The transfer of the embryos is done about 48-72 hours after puncture of the follicles and is done in an operating room without anesthesia. Afterwards, the patient receives instructions for daily progesterone. A week later, her hormone levels of estradiol and progesterone in the blood will be tested to see if a treatment change is needed. A pregnancy test is performed on the 14th day after the return.
Extra embryos are frozen. The pregnancy success rate from frozen embryos is lower than the rate from fresh embryos (about 25%). The embryos are stored in special test tubes marked with an identification number for each patient.
Prior to freezing, the embryos are transferred to a special growth platform containing antifreeze protective material designed to prevent the destruction of fetal cells when the temperature is lowered in liquid nitrogen. Prior to their return to the uterus, the embryos are thawed through a slow process. Not all embryos survive the freezing and thawing process.
Intra Cytoplasmic Sperm Injection (ICSI)
In order to achieve higher fertilization rates, minimal numbers of sperm are required from the over a million sperm cells moving in the seminal fluid. A microsurgical egg fertilization method has been developed for patients whose sperm count is insufficient. Using ICSI, a single sperm cell is suctioned into a thin, hollow glass micropipette and injected directly into the egg cytoplasm.
Pre-Implantation Genetic Diagnosis
Preimplantation Genetic Diagnosis, PGD, is a technique used in IVF treatments to examine the genetic integrity of embryos before their transfer into the uterus. PGD allows couples and individuals with serious genetic disorders to reduce the risk of having a sick child.
Why Perform PGD?
The method is suitable for couples who already have one child suffering from a genetic problem or couples with a hereditary genetic disorder at high risk of having a child who suffers from the same problem. PGD can also be considered among couples suffering from repeated miscarriages as a result of genetic disorders. Today there are more than 300 chromosomal and enzymatic disorders that can potentially be prevented by PGD.
How is PGD performed?
The embryos are obtained through ivf with micromanipulation. Once the developing embryo reaches a developmental stage of about 8 cells (on the third day after fertilization), a single cell is removed from each embryo. Using this cell, a genetic diagnosis is done to reveal the presence of abnormalities in the number or chromosomes or genes. The diagnosis is usually received on the day of the test and afterwards the embryos that were tested and found healthy are returned to the uterus.
Surgical treatment methods for obtaining sperm cells in men with azoospermia
Men with Azoospermia Caused by Obstruction
In most cases it is possible to suction sperm cells from the epididymis without affecting testicular tissue. There are 3 main methods for this:
- MESA - Microsurgical Epididymal Sperm Aspiration: Exposing the tubular epididymis, cutting it and aspirating sperm cells from within it under the microscope.
- PESA - Percutaneous Sperm Aspiration: Sperm aspiration using puncture of the epididymis with a fine needle.
- TESA - Testicular Sperm Aspiration: Puncture with a fine needle to aspirate the fluid between the cells of the testicular tissue, usually used in cases where no spermatozoa were found from aspirating the epididymis due to blockage or damage from previous operations.
Men with Azoospermia Caused by Testicular Failure
Sperm can be looked for in the testicles by two main methods:
- TESE - Testicular Sperm Extraction: Exposure of the testicular tissue and removing several pieces of tissue for biopsy.
- TEFNA - Testicular and Epididymal Fine Needle Aspiration: A method of piercing the skin of the testicle with a fine needle and extracting sperm cells from the aspirated fluid.