In vitro fertilization (IVF) is a treatment option used for couples with infertility that cannot be treated using simpler methods. This procedure has excellent success rate but requires significant effort and can be expensive. For all of these reasons, advanced treatment options can be stressful. These natural stresses can be minimized if you understand the nuances of the various procedures. Understanding the applications for each procedure will help you obtain the appropriate treatment and maximize your chance for success.
In Vitro Fertilization (IVF)
Step One – Ovulation Induction
Hormone injections are given to stimulate multiple egg production. This is because the normal cycle usually produces one egg only, and pregnancy rates in IVF are better if a number of eggs can be collected. These injections are usually given subcutaneously (under the skin) and are much less uncomfortable than the previous generations of medication. We then monitor the progress of ovulation induction with ultrasounds and blood estrogen levels over several days.
Step Two – Egg Retrieval
An egg retrieval is performed by placing a special needle into the ovarian follicle and removing the fluid that contains the egg. This is a relatively minor procedure and is performed by visualizing the follicles with a vaginal ultrasound probe. A needle is directed alongside the probe, through the vaginal wall, and into the ovary. To avoid any discomfort, strong, short acting intravenous sedation is provided.
Step Three – Fertilization and Embryo Culture
Once the follicular fluid is removed from the follicle, the eggs are identified by the embryologist and placed into an inubator. The eggs are fertilized with sperm later that day by conventional insemination or by Intracytoplasmic Sperm Injection (ICSI).
During conventional insemination approximately 50,000 sperm are placed with each egg in a culture dish and left together overnight to undergo the fertilization process. The ICSI technique is used to fertilize mature eggs in the event of sperm or egg abnormalities. Under the microscope, the embryologist picks up a single sperm and injects it directly into the cytoplasm of the egg using a small glass needle.
ICSI allows couples with very low sperm counts or poor quality sperm to achieve fertilization and pregnancy rates equal to traditional IVF. It is also recommended for couples who have not achieved fertilization in prior IVF attempts. Special urological procedures are available to you for cases where it is difficult to obtain sperm or for men with no sperm in the ejaculate.
The eggs will be checked the following day to document fertilization and again the next day to evaluate for early cell division. They are now called embryos and are placed in a solution called media to promote growth. Until recently, embryos were cultured for three days and then transferred to the uterus and/or cryopreserved (frozen). We now have the ability to grow the embryos for five or six days until they reach the blastocyst stage. For some couples these blastocysts may have a greater chance of implantation, allowing us to transfer fewer embryos and lower the risk of multiple birth while increasing the chance of pregnancy.
On day two or three after fertilization, the embryos will be evaluated for blastocyst culture. If there is a sufficient number of dividing embryos they will be placed in special blastocyst media and grown for two or three additional days.
Step Four – Embryo Transfer
Embryos may be transferred on day 3, 5, or 6 after egg retrieval. Transfers on day 5 or 6 are called Blastocyst Transfers. They are placed through the cervix into the uterine cavity using a small, soft catheter. This procedure usually requires no anesthesia. It is similar to the Mock Embryo Transfer which will be performed prior to the actual IVF cycle.
Additional Advanced Technologies
(AH) is a procedure performed prior to transfer in selected cases. An embryo needs to escape or “hatch” from it’s protein shell, called the Zona Pellucida, before it can implant in the uterus. In AH, a chemical or a laser can be used to dissolve part of the zona, to facilitate the hatching process later. This technique is often used with prior failed IVF cycles, female age over 38, and with abnormally thick zonae.
Percutaneous Epidydimal Sperm Aspiration and Testicular Sperm Extraction (PESA and TESE)
Some men have no sperm in the ejaculate but still produce them in the testes. This may occur due to a vasectomy, to a congenital obstruction of the sperm ducts leaving the testes, or to inadequate development of the sperm such that they cannot leave the testes. In these situations, a urologist can remove sperm by placing a needle into the testis or the tubes that drain it. These procedures are done under anesthesia and can be very effective when combined with ICSI.
Embryos that are not transferred but continue to thrive in the laboratory can be cryopreserved (frozen). We recommend freezing for any high quality embryos that survive to the blastocyst stage. These embryos are stored in liquid nitrogen and can be thawed at a later date. While the pregnancy rates with frozen embryos are not as high, the procedures involved in preparing for a frozen embryo transfer are much simpler and less expensive. Freezing only embryos that survive to the blastocyst stage maximizes the chance for success in a thaw cycle.
Preimplantation Genetic Diagnosis (PGD)
Genetic testing on preimplantation embryos may be indicated for patients who are at risk for genetic disorders such as Cystic fibrosis or Thalassemia and for patients with infertility related to chromosomal abnor-malities such as recurrent pregnancy loss or repeated unsuccessful IVF.
In many situations, especially when a female patient is in her late 30’s and early 40’s, infertility may result from a decrease in ovarian function and a consequent fall in egg quality. In the event of a severe compromise in ovarian function, successful pregnancy is very unlikely. A treatment that often offers an excellent chance of success is to use eggs from a donor who is capable of producing good quality eggs. This is a complex treatment option from medical, psychological and ethical viewpoints, but one that provides a very good chance for pregnancy.