IVF is simply the uniting of egg and sperm in vitro (in the lab). Subsequently the embryos are transferred into the uterus through the cervix and pregnancy is allowed to begin. The process is done inconjunction with ovulation induction through drugs, monitoring of hormone levels and follicle scans with ultrasound.
‘In vitro’ is a Latin term literally meaning ‘in glass’. It refers to the glass container in the laboratory where fertilisation takes place. Although this is usually a dish, in the popular mind it was thought to be a test tube — hence the term ‘test-tube baby’. Thousands of IVF babies have been born worldwide since the technique was first used successfully in 1978.
What are oocyte/egg follicles?
Follicles are fluid-filled sacs that are located inside both of a woman’s ovaries. A woman is born with millions of these eggs follicles, each of which contains an immature egg at its center. Each month, thanks to certain hormones, multiple follicles will begin to develop. The one follicle that is the strongest will attract most of the follicle-stimulating hormone (FSH), a hormone secreted by the pituitary gland, causing it to break open and release an egg while the remain follicles die off. This is ovulation.
Who is Suited to IVF?
Below are some factors for using IVF:
- Tubal problems can mean a woman’s fallopian tubes are blocked or damaged, which can make it difficult for the egg to be fertilized or for an embryo to travel to the uterus.
- Male factor can include a low sperm count, problems with sperm function or motility which can inhibit sperm from fertilizing an egg on its own.
- Severe Endometriosis affecting both fertilization of the egg and implantation of the embryo in the uterus.
- Ovarian issues which prevent the release or production of eggs.
- Abnormal uterus shape, fibroid tumors
- Unexplained infertility
The IVF PROCESS
The IVF process involves various stages.
- Ovulation induction
- Egg retrieval
- Embryo culture and Fertilisation.
- Embryo Transfer
Treament usually begins with ovulation induction.
Ovulation induction is a type of medical therapy often performed alongside certain fertility treatments. Typically, medications that are used to help trigger the development of egg follicles are known as ovulation inducers. Ovulation induction often triggers the development of more than one egg during ovulation.
Ovulation is often induced in order to help women who cannot ovulate regularly produce an egg during their monthly cycle. Ovulation induction is also used in order to trigger the ovaries to release more than one egg during ovulation. Sometimes, inducing ovulation can allow two or three eggs to be released at once, therefore increasing your chances of pregnancy.
A variety of drugs are used and the doctor will decide which combination is most appropriate for you. You will be closely monitored while you are on these drugs as women respond to them in different ways and some have strong side effects.
Timing is extremely important when it comes to the IVF process. If your follicles develop too much, then the egg inside will become too mature for efficient fertilization. This can seriously affect the IVF process. For this reason, your ovaries will be monitored in order to keep an eye on your follicular development. This is typically done through ultrasound. When your follicles reach just the right maturity, egg retrieval can begin.
Egg retrieval is the process whereby a woman’s eggs are removed from her ovaries. These eggs are later mixed with a man’s sperm in order to facilitate fertilization.
At the time of egg retrieval, you’ll be given a sedation anaesthetic. Follicles from both your left and right ovary will be removed in a process known as follicular aspiration.
Follicular aspiration involves inserting a hollow needle through the top of the vagina and into the ovaries. This needle is then used to suction out any follicles that may be present in the ovaries.
In order to guide the needle into the appropriate area of the ovary, you will be given a transvaginal ultrasound. This will allow the doctor to insert the needle into your ovary at just the right place. Because this is done under sedation, you shouldn’t feel any pain.
Once the needle is in the proper position, the doctor will use it to aspirate any follicles inside of the ovary. These follicles will be immediately examined under a microscope to ensure the presence of a viable egg. The follicles will then be placed in an incubator.
Depending upon your age and the effect of your fertility medications, you may have between 5 and 20 eggs removed during the egg retrieval process.
The entire process typically takes between 15 and 30 minutes
Embryo culture is the term used to describe the process immediately follow egg retrieval. It is during the culture process that your eggs and your partner’s sperm will be combined in order to produce a fertilized egg (known as an zygote). Once a zygote has been formed, the culture process will continue in order to encourage the growth of the zygote into an embryo. Lasting from 2 to 5 days, the embryo culture process is vital to the success of any IVF procedure. Without accurate and controlled embryo culture, IVF transfer may not be successful.
Immediately following your IVF retrieval, any aspirated follicular fluid will be transported to our laboratory. Here, your follicular fluid will be examined under a microscope, in order to identify all eggs that are present. Each egg and it’s surrounding cells will then be washed in a special medium, in order to remove any toxins and impurities. These eggs will then be transferred, in separate dishes, to a special incubator containing carbon dioxide. The eggs will remain in this incubator until fertilization is ready to take place. This usually happens between two and six hours after egg retrieval, depending upon the maturity of the eggs.
When the eggs are matured, they will each be combined with some of your partner’s sperm. His sperm will have been washed and divided up into specific amounts.
The sperm and egg will be combined in a dish that contains special culture medium. This culture medium, is designed to help the embryo during the first days of division. The dish is then placed back inside of the incubator.
Monitoring the Embryos
Your developing embryos will be monitored carefully by an embryologist
After 24 hours of development, the embryologist will make the first check on your embryos. By this stage, your embryos will still be single cells. However, they will contain two clear bubbles (known as pronuclei) inside. These pronuclei are evidence that the embryo contains genetic material from both you and your male partner. Embryos without pronuclei are discarded.
Your embryos will then be left to develop for another 24 hours. At this point, embryos will be monitored for cell division. Most embryos have developed into two or four-cell embryos at this point.
Embryo transfer is one of the most important parts of the IVF process. It is during this final stage of the IVF procedure that your embryos will be transferred into your uterus, in the hopes that you will become pregnant. Embryo transfer is completed after your eggs have been fertilized by your partner’s sperm and they have been through the embryo culture process.
How Many Embryos are Transferred?
Generally, between two and four embryos are transferred during each IVF cycle. The exact number of embryos that you have transferred will depend upon a number of factors, including:
- the number of embryos that were formed after egg retrieval
- the health of your embryos
- your age
- your risk level for multiple pregnancy
Your embryo transfer will be performed at the clinic. It is a completely painless procedure, so you will not have to receive any type of anaesthetic during the transfer. You may receive some medication to relax the uterus.
You and your partner will be asked to come in an hour before the transfer procedure. Your embryologist will also discuss with you which embryos are the healthiest to have transferred into your uterus and how many embryos should be transferred. You and your partner will be able to see pictures of your embryos before the procedure begins.
Once your embryos have been selected, they will be immersed in a fluid and stored in a special catheter. You will be asked to lie down on an examination table and a speculum will be inserted into your vagina. This allows the doctor to access your cervix. Your cervix will be cleaned of any cervical mucus, which could interfere with the placement of the embryos. A flexible, rubber catheter will then be inserted into your cervix and up into your uterus. The catheter containing your embryos will then be placed inside of this rubber catheter.
The doctor may perform an abdominal ultrasound in order to determine the best place inside of your uterus to deposit your embryos. This is usually in the space at the very top of your uterus. Once this location has been found, the embryos will be pushed out of the catheter and into your uterine lining.
After Embryo Transfer
It is usually recommended that you take it easy for a couple of days after the transfer. After 48 hours though, you can resume your normal activities – these will not affect implantation in anyway. You will be given progesterone supplementation which is to be used timeously. In 12 days, you and your partner will return for a blood test to find out if you are pregnant.
Typically, most couples have leftover embryos remaining from the IVF process. You and your partner will need to decide what you would like to do with your embryos. There are a number of available options, including embryo cryopreservation and embryo donation. These options allow you to store your embryos for your own future use or to help other couples who are suffering from infertility to conceive
How long will treatment last
One cycle of IVF takes four to six weeks to complete. You and your partner can expect to spend about half a day at your clinic for the egg retrieval and fertilisation procedures. You’ll go back two to three days later for the embryos to be transferred to your uterus.
What’s the success rate?
Outcomes vary greatly depending on your particular fertility problem and, more importantly, on your age — younger women usually have healthier eggs and higher success rates. The national average success rate is around 35-40 per cent. This represents your average chance of delivering a healthy baby for each cycle of treatment