In vitro fertilization is an option for many couples who cannot conceive through conventional therapies. Embryos are put back into the female partner's uterus (womb) after 3 to 5 days of being in the incubator, hopefully they will then grow into a baby. The reasons IVF is done include - poor sperm quality and/or quantity, obstructions between the egg and sperm, ovulation problems, and sperm-egg interaction problems. These problems can prevent couples having a baby naturally, and IVF helps to solve this.

How might we benefit from IVF?

IVF is likely to be recommended for the following fertility problems:

•If you have blocked or damaged fallopian tubes or any other problem where IVF has been identified as the only treatment likely to help you get pregnancy.

•If your partner has a minor problem with his sperm. Major problems are better treated using ICSI.

•If you have tried fertility drugs, such as clomiphene, or another fertility treatment such as IUI, without success.

•If you have been trying to conceive for at least two years and a cause hasn't been found to explain why you have not become pregnant.

How is IVF done?

IVF follows a series of steps, starting with fertility drugs to help you produce as many eggs as possible.

Fertility drugs

You will probably need to take fertility drugs to stimulate your ovaries to develop mature eggs ready for fertilisation. During your normal menstrual cycle you release one egg per month. Your odds of getting pregnant are better with more eggs and using fertility drugs increases the number of mature eggs that are released. It's recommended that IVF be offered with fertility drugs to stimulate your ovaries as you have a better chance of pregnancy as a result.

This is called down-regulation and  usually involves drugs called gonadotrophin-releasing hormone (GnRH) analogues (pituitary agonists) to suppress or stop your cycle. You take these daily for about two weeks by tablet or injection.

Other shorter methods of taking control are available. Some involve the use of GnRH antagonists. These drugs can be taken over a few days, usually after pre-treatment with the contraception pill and at the start of ovulation stimulation. This method is not common  but is suitable for women who are at higher risk of severe side effects of fertility drugs.

If you have endometriosis you may take the GnRH agonist Cetrotide for several months to help improve your egg quality and chances of success.

Hormone injections

You will then have daily hormone injections for about 12 days. These stimulate your ovaries to release a greater number of mature eggs than usual (ovulation induction). The hormones used are gonadotrophins follicle stimulating hormone (FSH) and luteinising hormone (LH).

Women respond to these fertility drugs in different ways, and they may have strong side-effects. Your doctor will closely monitor you to make sure that you are cared for if this happens.

Ultrasound scans and possibly blood hormone tests will be offered to monitor how many and how well your eggs are responding. This is for safety and to check when your eggs are mature.

Egg retrieval and sperm collection

Ultrasound is used to detect when your eggs are ready to be retrieved.

Your doctor will then remove the eggs from your ovaries. Your doctor will use a fine, hollow needle attached to an ultrasound scan probe. The probe helps to locate the follicles that contain the eggs. You may feel mild discomfort during the procedure, but if you feel pain later on your specialist will prescribe painkillers.

While your eggs are being collected, your partner will need to provide a fresh sample of semen. If donated sperm or frozen sperm are being used, the sample is taken from the freezer. The sperm is washed and the best-quality sperm extracted ready to fertilise the eggs. The sperm is then combined with the eggs in a dish and left to culture in an incubator.

Fertilisation and embryo transfer

Within one day of combining the eggs and sperm, the dish is checked to see if any eggs have been fertilised. If they have, they'll be kept for between two days and five days before being transferred back into your uterus.

Any fertilised eggs will each have become a ball of cells called an embryo. They may also be referred to by your specialist as blastocysts, if the embryos are being transferred at the later blastocyst stage, at about day five. The healthiest embryos are chosen to be inserted into your uterus.

Some clinics offer a pre-implantation test called comprehensive chromosome screening (CCS). This screens embryos before they are transferred at the blastocyst stage. Only the embryos that are predicted to have a full set of chromosomes are selected.

CCS may boost your chances of getting pregnant and may also reduce your risk of miscarriage when a single embryo is transferred.

By now you will have been helping your uterus (womb) to prepare for the embryo by taking progesterone, which helps thicken its lining. You receive this by injection, pessary or gel. If your uterus lining (endometrium) is too thin, the embryos are unlikely to implant. If this is the case, the IVF cycle will unfortunately be abandoned.

Usually, one or two embryos are transferred with a thin catheter (tube) through your cervix into your uterus. Your fertility specialist may use ultrasound to guide him.

To avoid the risk of a high order multiple pregnancy, no more than three embryos can be legally transferred. The number of embryos that are transferred will depend on your age and your chances of success. This in turn depends on your particular fertility problem.

Dr. Dabit  recommends a maximum of two embryos transferred to your uterus whatever your age. If you are 39 years old or under and a suitable candidate, you may be recommended for elective Single Embryo Transfer (eSET) in your first and second cycles. If you have one or more top quality embryos, eSET can increase your chance of having a healthy single baby at term, and improve your and your baby's health.

If you are 40 years or more Dr. Dabit supports the transfer of two embryos per cycle.

Repeated cycles

If there are any extra embryos, these may be frozen for future use. This is in case the first cycle doesn't succeed, or you want another baby after your successful treatment.

IVF normally involves transferring embryos at about two to three days after fertilisation. Another option is to wait until about five days after fertilisation when the ball of cells has developed into a blastocyst. Only the healthiest embryos will reach the blastocyst stage in vitro. You may have a better chance of having a healthy pregnancy after blastocyst transfer.

Most clinics offer blastocyst transfer to all patients depending on quality and number of embryos available. However some clinics offer blastocyst transfer only if:

•you have had previous normal IVF with healthy embryos but they have not implanted

•you are under 40

•you have opted for eSET

You can be up and about quite soon after embryo transfer, as resting for more than 20 minutes immediately afterwards makes no difference to the outcome. In a successful cycle, one or more embryos will implant in your uterine wall and will continue to grow. You can take a pregnancy test in about two weeks.

Once your pregnancy has been confirmed following IVF, you should have an early ultrasound scan at about six weeks. This is to check that the embryo has implanted in your uterus.

How long will IVF treatment last?

One cycle of IVF takes between four weeks and 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 between two days and three days later for the embryos to be transferred to your uterus, or between five days and six days with blastocyst transfer.

What's the success rate of IVF?

The success rates depends on your particular fertility problem and your age. The younger you are, and the healthier your eggs are, the higher your chances of success.

You can improve your chances of success by:

•Reaching a healthy weight for your height before you have treatment. IVF is more likely to be successful if your body mass index (BMI) is between 19 and 30.

•Keeping your alcohol consumption to no more than one unit of alcohol per day, as drinking more than this reduces the effectiveness of IVF.

•Stopping smoking (this includes your partner!) Smoking reduces success rates.

•Keeping your caffeine consumption very low. Even low rates of consumption of 2 to 50mg have been linked to lower success rates.

What are the advantages of IVF?

For most children conceived by IVF there are no long-term problems.

IVF can offer you a chance of having a baby if you are unable to conceive naturally, for example if you have blocked, damaged or missing fallopian tubes.

What are the disadvantages of IVF?

IVF increases your risk of certain complications, such as:

•A multiple birth, when more than one embryo is transferred to your uterus. Many couples consider twins to be a blessing. But a multiple pregnancy increases your risk of having a premature baby or a baby with a low birth weight.

•Side-effects from fertility drugs are usually mild, and include hot flushes, headaches and nausea. However, you will need to be closely monitored for signs of ovarian hyperstimulation syndrome (OHSS), particularly if you have polycystic ovary syndrome (PCOS). Having OHSS may mean an interruption or cancellation of the treatment cycle and a stay in hospital while your over-stimulated ovaries settle down.

•An increased risk of ectopic pregnancy, where an embryo implants in a fallopian tube or in your abdominal cavity. This is more likely if you have previously had problems affecting your fallopian tubes.

Despite these risks, many parents still go on to give birth to much-wanted, much-loved babies through IVF. If you are considering fertility treatment, Dr. Dabit clinic offers advice and contact details for counsellors.