In Vitro Fertilisation (IVF)

1 In Vitro Fertilisation (IVF)
- 1.1 In Vitro Fertilisation In Detail
- 1.2 Pages from Infertility treatment Guide

In vitro fertilisation (IVF) forms part of a group of similar procedures sometimes called Assisted Reproduction Technology (ART). In fact, IVF forms the main platform on which several other treatments for infertility are based. Essentially in IVF, mature eggs are harvested from the ovary and fertilised with sperm from a male partner or donor and inserted back into the female. Although this sounds simple, it involves a series of complex steps, each of which may fail. As fertilisation occurs in a laboratory, in glass dishes or containers, IVF babies are also known as "test tube babies".

In Vitro Fertilisation In Detail

In vitro fertilisation has been around for almost 30 years. Over 1 million babies have been conceived in this way. IVF is the commonest ART procedure. Success rates for IVF vary greatly but are on average around 15-30%, which is actually very similar to success rates for natural conception. Success can depend on a number of factors. These include;

maternal age: as women get older, the quality of their eggs decreases and the chances of conception also decline,
the cause of subfertility: the more complex and more numerous the reasons for the failure to conceive naturally, the lower the success rates with IVF,
the number of embryos implanted: the right balance must be found between implanting a few healthy embryos to ensure reduction of complications during pregnancy versus insertion of a larger number of embryos to ensure that some will survive even if others perish,
the expertise of the clinic: there are differences between success rates at different clinics depending on their experience and degree of expertise in this field.

Which Couples Should Consider IVF?

To some extent, this decision should be taken only after consulting your infertility specialist. There are a number of other options which are simpler, less expensive and may yield similar success rates for appropriate couples. However, almost any of the causes of female or male (or both) infertility listed in the page entitled "Causes of Infertility" may be suitably treated using IVF. Examples of problems for which IVF can be used include;

older women,
fallopian tube damage or obstruction,
low sperm count or poor quality sperm in men,
unexplained infertility,
failure to conceive using other methods such as ovulation induction or intrauterine insemination (IUI).

When referred to an assisted conception unit, couples will usually be assessed using several different tests, scans and procedures. A more detailed discussion of these tests can be found by reading "Infertility Tests for Women" and "Infertility Tests for Men".

A decision can then be taken as to the most suitable method for assisted conception.

How is IVF done?

IVF is most often carried out in an induced cycle, i.e. ovulation is artificially induced using hormone drugs. Please read "Drugs Used in Infertility" for further details regarding this subject. Using induced cycles, a number of eggs may be harvested from the ovaries at the same time. However, this need not always be the case. A single egg can be collected during natural ovulation and used for IVF in the same way. Obviously, only one fertilised egg can then be inserted into the womb.

To understand the complexities of IVF, it is best to divide the whole process into stages as follows;

1. Investigation

Before anything else can be done, the clinic needs to assess both the male and female in the couple to ascertain the reason for the lack of conception. This is done in the ways described in the previous pages and may take several days or weeks to complete depending on where the various investigations are carried out.

2. Ovarian Stimulation.

Various drugs are used to take control of the menstrual cycle. Other hormonal drugs are then used to stimulate the ovaries into starting the egg maturation process. Several eggs will start to develop simultaneously.

3. Developmental Checks

Blood tests and vaginal ultrasound scans are carried out regularly to assess the development of the eggs. From here on, timing is crucial as an injection of another hormone is given approximately 36 hours before egg collection. This injection forms the final phase of egg maturation, at the end of which, eggs will be ready for harvesting.

4. Egg Collection

This is done immediately after Step 3. If done too early or too late, the chances of successful conception are greatly reduced. Collecting eggs can be done in 2 ways;

Ultrasound guidance: this can be done with a local or general anaesthetic and takes around 30-60 minutes. A vaginal ultrasound scan is used to guide a needle through the vagina and into each ovary in turn. The needle is guided to each egg sac and the eggs are sucked into the needle and retrieved. Generally, this is the favoured approach these days.

By laparoscopy: this is done using a general anaesthetic. A thin telescope like instrument containing a light and camera is inserted through a tiny incision, into the abdomen to view the pelvic organs. A needle is then inserted to the egg sacs to suck out the eggs. This procedure is used less often these days.

5. Sperm Collection

This can be done in 2 ways;

Using your own sperm: a sample is produced by masturbation very close to the time of egg collection. This is done either close to or at the clinic. This is vital as the laboratory requires immediate access to the sperm. Sperm may also be collected using various surgical sperm extraction procedures. They can be extracted directly from the epididymis using methods such as Percutaneous Epididymal Sperm Aspiration (PESA) or Microsurgical Sperm Aspiration (MESA), or from the testicles using Testicular Sperm Extraction (TESA).

Using a sperm donor: if this option is chosen, then sperm will already be available to the clinic. Many samples may be kept by the clinic and a suitable sample is selected. The discussion about donor sperm and which sample to use is usually had at the outset of treatment. Clinics may try to match certain characteristics of the sperm donor to the male partner in the couple. Traits such as hair colour, eye colour, height and build can be matched. These sample are kept frozen for 6 months and tested for various sexually transmitted infections such as Hepatitis B and HIV before being deemed suitable for use.

Once a semen sample is obtained, sperm are separated from the plasma (consisting of seminal fluid), washed to remove chemicals and infections and spun using a centrifuge at high speed so that the "best" sperm can be selected.

6. Fertilisation

The collected eggs and selected sperm are mixed together in a glass dish and left for 16-20 hours. They are then assessed to see if any of the eggs have been fertilised. Eggs which remain unfertilised or those that show abnormalities are discarded. The remaining healthy fertilised eggs (now embryos) are left to incubate for another 24-48 hours.

7. Preparing the Womb

2 days after egg collection, women are given a dose of progesterone by pessary, gel or injection. This starts the process of preparing the womb (uterus) to receive the embryo by thickening the womb lining (endometrium).

8. Transferring the Embryos to the Womb

Between 2-5 days after fertilisation has taken place, 1-3 of the best and most healthy embryos are selected for transfer. This is done by inserting a catheter into the vagina, through the cervix and into the inside of the uterus. The appropriate number of embryos are then injected through the catheter and into the womb. Implantation occurs naturally. Following embryo transfer, women are often advised to stay lying down for several hours.

The decision as to the number of embryos to insert is a complex one. If not enough are inserted, the chance that none will survive is greater. But if many are inserted, the chance of a multiple pregnancy with all of it's complications is greater.

9. Dealing with the Remaining Embryos

Once the correct number of embryos are inserted into the womb, a decision is made on the remainder. The choices include;

discarding the embryos if no further attempts at IVF are to be made,
freezing the embryos for use in another IVF cycle. In these cases, steps 1-6 are eliminated as embryos are already present,
the embryos are donated to another couple.

10. Confirming Pregnancy

A pregnancy test can be performed 2 weeks after embryo transfer, either at home by using a urine pregnancy test or at the clinic by either a urine pregnancy or blood test. If pregnancy is confirmed, the usual antenatal care will be initiated in most cases. In some, there will be extra input and closer monitoring of the pregnancy if it is deemed to be at higher risk. Higher risk cases include;

women aged 40 years or over,
multiple pregnancy,
a history of previous complications of pregnancy including recurring miscarriage, stillbirths or developmental anomalies,
a history of maternal complications such as pre-eclampsia.

What are the Complications and Risks of IVF?

1. Side Effects from the Use of Fertility Drugs

Side effects can include: abdominal pain and discomfort, flushing, breast pain, mood swings and headaches as well as many other symptoms. Although most of these symptoms are mild, some may by troublesome and require treatment such as pain killers.

2. Pain

Some procedures can by uncomfortable, especial egg collection, after the anaesthetic wears off. This again requires pain killers sometimes.

3. Infection

This is rare these days as meticulous preparation of sperm takes place before fertilisation. All instruments used are sterilised in the usual way and invasive procedures are done in sterile operating theatres.

4. Ovarian Hyper-Stimulation Syndrome (OHSS)

This is a well recognised potential side effect of trying to artificially stimulate the ovaries to produce eggs for ovulation. It occurs with the use of some infertility drugs. OHSS can be dangerous and usually requires hospital assessment and monitoring in severe cases.

Fertility drugs over react and excessively stimulate the ovaries. Multiple cysts develop on the ovaries and fluid builds up in the abdomen. In more severe cases, the ovaries swell and fluid fills the abdomen and chest cavities. There then develops a risk of blood clots and kidney damage.

Symptoms include;

abdominal swelling or distention
nausea and vomiting
abdominal pain
breathlessness
feeling faint

Women who are taking infertility drugs and who experience these symptoms should contact their clinic immediately. Treatment for infertility will usually be stopped. In severe cases, you may require urgent admission to hospital.

5. Ectopic Pregnancy

An ectopic pregnancy is where the embryo attaches to the wall of a fallopian tube rather then the wall of the womb. This unfortunately leads to a non-viable pregnancy as the fallopian tubes are not able to sustain the growing embryo beyond 8-10 weeks. If left untreated, the tube will rupture, causing bleeding inside the pelvis. This is a potentially fatal situation for the mother. The embryo must therefore be surgically removed. It is sometimes possible to save part or all of the fallopian tube though generally, the tube is also removed.

Symptoms of an ectopic pregnancy include; vaginal bleeding, lower abdominal pain, shock and death. The chances of ectopic pregnancies seem to be higher in women undergoing IVF, possibly as a result of their tubes already being damaged, thus necessitating the need for IVF in the first place.

6. Multiple Pregnancy

The chances of having multiple pregnancies is considerably higher with IVF than with natural conception. The more embryos are transferred, the greater the risk. Also, the greater the number of embryos that succeed in implantation, the greater the complication rate for the pregnancy as a whole. Problems include;

an increased risk of miscarriage,
an increased risk of low birth weight,
an increased risk of stillbirths.

7. Emotional Problems

This can be a long standing issue contributing to the lack of natural conception or it may be as a result of going through the sometimes difficult and psychologically traumatic process of assisted conception. Either way, most well run and successful clinics will offer counselling for couples before and throughout the IVF process. Couples should feel free to discuss their fears and concerns. They should also be encouraged to be open with themselves and discuss how they feel with their partners. Having access for both males and females in a couple to counselling is vital for the process of assisted conception to be successful.