When is In Vitro Fertilization (IVF) necessary?

In vitro fertilization performs part of the reproductive process in the laboratory. This is especially useful in several situations:

1. When the fallopian tubes are affected, that is, they are obstructed or dilated, and are not able to perform their function of transporting the embryo to the uterus. Therefore, it is necessary for this work to be done externally.
2. When the spermatozoa have an important alteration and are not able to reach from the vagina to the tube, where they would meet the ovum.
3. When there is little ovarian reserve. IVF is recommended for women over 38 years of age due to the low efficacy of other reproductive techniques.

IVF is also essential for some treatments, such as preimplantation genetic diagnosis (PGD), the use of vitrified eggs or all treatments with donor eggs.

What are the phases or stages of in vitro fertilization?

Before starting the process of in vitro fertilization, a basic study of the woman or couple must be done to assess whether they are candidates for treatment:

• Blood tests for HIV, Hepatitis B and C and syphilis, as required by law.
• Assessment of ovarian reserve with an ultrasound, to perform an antral follicle count.
• Specific hormone determinations, such as Antimullerian, very useful to see the ovarian reserve.

If there is a male partner, a study must also be performed. As with the woman, a blood test to rule out sexually transmitted diseases and an evaluation of the seminogram must be performed.

Once the study is done, the in vitro fertilization treatment is performed. The main phases are:

1. Ovarian stimulation: the aim is to obtain as many eggs as possible, in order to have raw material to work with in the laboratory. In this phase injectable drugs are used. The treatment begins in the first days of the period. They are subcutaneous injections that are given to the patient at home, although it is necessary to carry out some ultrasound checks during the treatment to evaluate the response of the ovaries.
2. Extraction of the eggs: the extraction is performed in the laboratory, with vaginal ultrasound control and sedation (not general anesthesia).
3. Laboratory process: the following day it is possible to observe if a correct fertilization has taken place. The culture of the embryos is a process that can take 3 to 5 days. The process can be performed in two ways:
   • Conventional in vitro fertilization, that is, by placing sperm next to each egg and letting them alone enter the egg. Although this technique is less and less used.
   • Microinjection technique, i.e., a selected sperm is taken and introduced into the egg. This technique solves situations in which the number of sperm is extremely low or in which the raw material of eggs is also low. This technique achieves better results than conventional in vitro fertilization.
     The day after fertilization is performed in the laboratory is when it is possible to observe whether the process has been carried out correctly and the egg is fertilized. Once the embryo is in the laboratory, a cell culture process begins, which can last up to three days or even five days.
4. Selection and transfer of the embryos: according to the couple and with the advice of the biologists, it is decided how many embryos will be transferred to the uterus. It can be one embryo, two (sometimes) or three (exceptionally and the maximum allowed by law).

And after the treatment, is there any special care to be taken?

The most important thing is to correctly follow the treatment with progesterone supplements and sometimes estrogens that you have been prescribed. All assisted reproduction specialists agree on this.

However, rest, a classic recommendation, has not proven to be effective (embryo quality and endometrial receptivity have a much greater influence on the outcome). It is also advisable to act as if you were pregnant and avoid alcohol and the intake of drugs that may be contraindicated in pregnancy.

What are the success rates of this technique?

The IVF technique is a much more efficient technique than the first-step techniques, such as artificial insemination, and it also provides much more information about what is happening.

With artificial insemination we can expect a pregnancy rate for each cycle performed of 10% or at most 15%, up to 20% in ideal cases when donor sperm is used and in young women. However, in IVF the average rates can be around 40%, plus what can be added with the embryos that can be left vitrified. This is a general figure, since to be realistic this has to be adapted to each specific case. The pregnancy rate for a 33 year old patient with a good ovarian reserve is not the same as that of a 40 year old patient, which can drop to 10% with the use of her own eggs. This is very important for women to keep in mind when it comes to not letting the years go by if getting pregnant is in their plans.