The early use of IVF was to help couples when the woman's tubes were removed, blocked or diseased to the point that a pregnancy was unlikely to occur. Today, IVF is also used for couples with infertility due to other causes, male fertility problems or unexplained infertility.

Stimulation of the Ovaries

Normally, a woman produces one egg each menstrual cycle, which is not enough for the high numbers needed during an IVF cycle. So for IVF, drugs are used to stimulate the ovaries to produce many eggs. The woman is monitored closely through blood tests and ultrasound examination to determine the best time to remove the eggs. The fertility clinic is able to:

Assess that the drugs are working to produce the follicles which contain the eggs.
Check that the drugs are not working so well that follicles are becoming too large.
Determine the best time to harvest the eggs.

This is an emotionally and physically draining time for the woman as there is much uncertainty and it requires many visits to the fertility clinic. Some women find it is easier to be off work during an IVF procedure.

Removing the Eggs - Fertilization

The operation is done with the woman under a very light anesthetic so that she is not quite asleep. A special ultrasound probe is placed into the vagina and the ovaries can be seen clearly. A needle is passed through the top of the vagina into the ovaries guided by the ultrasound picture. Fluid from the follicle is sent to a lab, where the scientist isolates the egg if one is present.

When all the eggs have been collected, the male partner provides a semen specimen from which the sperm can be collected. The moving sperm are selected and added to the eggs and the sperm-eggs mixture is placed in an incubator to allow fertilization to take place. This is studied at regular intervals to determine that fertilization has occurred and that cell division is taking place normally. In some situations, the sperm may be inserted right into the egg to cause fertilization to occur.

Embryo Transfer

If the embryo develops, it is placed into the woman's uterus about two days after the eggs are collected. The embryo transfer procedure is simple and not much more uncomfortable than a pap smear. A catheter is placed at the top of the uterus and the embryos are deposited - normally, a maximum of three. If there are more than three available, the rest will be frozen and stored for future use.

Problems with IVF

Unfortunately, as with many procedures, IVF does not always work as hoped.

Not all women respond to the drugs used to stimulate the ovaries.
Some women respond too well to the drugs, which must be stopped to prevent stimulating the ovaries too much.
Eggs may not be obtained.
Eggs may not be fertilized.
Fertilized eggs may not grow into embryos.
Embryos may not implant. This is the most common cause of failure.

Miscarriages and birth defects are no more common with IVF than in normal pregnancies. Long-term problems are not yet known, since the first successful pregnancy was in 1978.

Cryopreservation (Freezing) and Later Replacement of Embryos

Most couples choose IVF with cryopreservation (freezing) and subsequent replacement of the embryos. This means that fewer fertilized eggs are returned to the uterus after the initial IVF cycle. The remainder, if suitable, will be frozen. The frozen embryos are thawed and may be replaced, one or two at a time, in a later cycle. This avoids the need for the costly drug manipulation and egg retrieval procedure. Embryos are only placed in the woman from whose uterus the eggs were first removed.

The major benefit of using frozen embryos is the marked increase in success rate. The Foothills Clinic in Calgary, for one, has a success rate of over 50 per cent over several cycles. Thus, where the couple has tried as many IVF and frozen embryo cycles as they want up to a maximum of three, they have a 50 per cent chance of success. This compares to a success rate of 16 to 18 per cent for one IVF try.

Costs

Costs vary and the infertility clinic will provide you with the cost as part of their counselling service. This service is not usually covered by Provincial Health Plans.

Legal Implications

There are many legal implications, especially with the use of frozen embryos. These should be discussed in detail with health care professionals at the fertility clinic. One issue is what to do with the embryos should there be a divorce or death.

Emotional Implications

IVF is an extremely emotional time for most couples. They know that this may be their last chance for pregnancy and they come into the program quite desperate. Most clinics have professional counsellors to help couples deal with the emotional turmoil they are experiencing.

It is important to many couples to know that they have explored all avenues open to them before giving up on their hopes and dreams. Just the act of trying can be an end in itself for many. For those who succeed, their dreams become reality.

In-Vitro Fertilization Another chance at pregnancy

In-vitro fertilization (IVF) is a technique that gives infertile couples the chance to achieve a pregnancy. It involves removing eggs from the ovaries and fertilizing them in the laboratory. Some of the embryos that develop are placed into the uterus where they may mature.