Understanding In-Vitro Fertilization

What is In-vitro Fertilization or IVF?

In-vitro fertilization (IVF) is an infertility treatment technique. In IVF, the fertilization of the egg and the sperm take place in a glass dish in the laboratory. Hence the popular term, test-tube babies. The fertilized egg is transferred to the uterus within a couple of days and allowed to grow normally in the woman's womb.

It is an ideal technique for couples with non-functioning fallopian tubes. It can be used as a treatment option for various other infertility problems such as endometriosis, pelvic adhesions, low sperm count and unexplained infertility. IVF can be an expensive and often stressful procedure. So, it is generally used only after most other treatment options have been tried.

Preparing for IVF

A successful IVF procedure needs healthy eggs, sperms and a uterus capable of carrying a pregnancy to full term. The doctor will perform a few tests to evaluate all three before performing an IVF. Some common tests used to evaluate these are

• Sperm survival test

  This is done to check if adequate sperms can be recovered.

• Ovarian reserve test

  Used to check if the woman can produce enough healthy eggs.

• Hysteroscopy

  This is used to check if the uterine cavity is normal.

Other preliminary tests that maybe conducted include blood tests to check for immunity to rubella, Hepatitis B and AIDS. A blood hormone test is used to check the response to fertility drugs.

How is In-vitro Fertilisation or IVF done?

In IVF, the fertilisation of the egg and sperm takes place in a glass dish in the laboratory. After fertilisation, the embryo is transferred into the woman's uterus. The steps that are involved in an IVF are:

• Superovulation

  - The woman is given fertility drugs to induce her ovaries to produce many mature eggs as against the single egg produced in a normal cycle. This is done as the chances of pregnancy are higher if more than one fertilized egg is transferred back to the uterus. The drugs are administered over a ten day period.

• Egg Retrieval

  - During the second phase, the eggs are retrieved from the woman. Timing is very important in an IVF to procure mature eggs. The eggs are scanned frequently with vaginal ultrasound after Day 10 of the cycle. Once the doctor decides that the eggs are mature they are retrieved using minor surgery under intravenous sedation. A needle is inserted into your vagina. The follicular fluid containing the egg is sucked out through the needle into a test tube. All the follicles are aspirated, one by one. It is common to retrieve 5-15 eggs during this process.

• Fertilisation and Egg Culture

  - The eggs are separated from the follicular fluid in a laboratory. They are washed in a medium and the most mature eggs are transferred into an incubator. The incubator has the same temperature as that of the woman's body. The culture medium is simulated with the same conditions as the woman's fallopian tubes. Sperms are added to a dish containing each egg in the ratio of 75000:1. It takes about a day and a half's wait to determine the number of eggs that have been fertilized. Ideally, you have multiple embryos that can be transferred back to the uterus. However, in some cases there maybe no fertilized eggs. This can be due to a problem in either the egg or the sperm. Poor lab conditions can also be the cause for this in some cases. In this case, your doctor may advise you to try again in the next cycle.

• Embryo Transfer

  - After a couple of days, the embryo is transferred into your uterus through your cervix using a catheter. This process lasts for about 10 to 20 minutes. You are usually advised a bed rest after the transfer. The number of embryos that are transferred back into the uterus is decided between the doctor and you. Usually anywhere between 1-4 embryos are used. Using a large number of embryos increases the chances of a pregnancy but also increases the chance of multiple pregnancies. Some hospitals also have facilities to freeze the embryos and use them in a subsequent cycle if needed.So, weigh your options carefully before deciding on this.

Once the embryos have been transferred back to the uterus, it is back to Mother Nature to do her magic. The implantation of the embryo in the uterine lining is a complicated process and we have no control over it. You will find out if you have become pregnant or not within 10-14 days of the transfer. A regular pregnancy test kit or blood test will confirm if you are pregnant. The success rate of IVF largely depends on the couple's fertility problems and their age. Younger women have a higher success rate. A key advantage of IVF is that it has been adopted from a very long time and is therefore quite common. Also, chances of multiple pregnancies are less.

Drawbacks of IVF

One drawback of IVF is that it is costly and time consuming. Its side effects include - The fertility drugs sometimes cause ovarian hyperstimulation syndrome (OHSS) due to excess egg production. Because of this, the ovaries swell greatly causing fluid to accumulate in the abdominal cavity. Some women also suffer from shortness of breath, dizziness, pelvic pain, nausea, and vomiting.

IVF is not advisable in the following cases:

• Women with failing ovaries or a damaged uterus
• Men with sperm count lesser than three million motile sperms