In Vitro Fertilization, as known as IVF, is a procedure by which a woman’s eggs are extracted from her ovaries and fertilized by her partner’s sperms in the laboratory. The resulting embryos are incubated for three to five days and are then transferred into the uterus or cryo-preserved for a future cycle.

A woman undergoing IVF will have her ovaries stimulated with Gonadotropin subcutaneous injections (GNT’s) to produce a sufficient amount of eggs. She will be closely monitored through her cycle with blood work and ultrasound to determine the optimal time for the retrieval of her eggs. When her eggs reach maturity, she is given a subcutaneous injection called “Ovidrel” (or HCG) which will begin the process of ovulation. After 35 hours, she will undergo intravenous sedation and her eggs will be retrieved through needle aspiration in the operating room located in our clinic. Her partner will provide a sperm sample which will be used to fertilize her eggs immediately following the retrieval.

Couples diagnosed with any of the following may benefit from IVF treatment: 

  • Damaged, blocked or previous ligation of fallopian tubes
  • Male factor (including low sperm count or previous vasectomy)
  • Advanced maternal age (over 38 years old)
  • Reduced ovarian reserve (low quality or quantity of eggs)
  • Severe Endometriosis
  • Polycystic Ovarian Syndrome (PCOS)
  • Unexplained Infertility

The first IVF baby, Louise Brown, was born in England in 1978. Since then, there have been approximately four million children born through In Vitro Fertilization.

An IVF cycle has different stages:

  1. Study and preparation of the patients.
  2. Ovarian stimulation.
  3. Egg retrieval.
  4. Laboratory fertilization: Oocytes, spermatozoid and embryo culture.
  5. Embryo transfer to the recipient mother.


      1.Study and preparation of the patients

This process ensures that IVF is the correct solution to the patients’ infertility problems and that they are physically and psychologically ready to begin the cycle. If this is not the case, the patients are offered other treatment options.

     2.Ovarian stimulation

In order to maximise the possibility of pregnancy, we need to obtain more than one oocyte, which is the number a woman’s ovary normally produces. In order to stimulate the production of several oocytes and guarantee their quality, we provide a combination of medicines whose response is monitored with vaginal ultrasound scans and occasionally blood tests.

The whole process lasts approximately between 8 and 12 days, depending on each case. The treatment can be cancelled if a low or exaggerated ovarian response is observed.

      3. Oocyte retrieval

Once the oocytes are mature, we retrieve them with the guidance of a vaginal ultrasound scan under local anaesthesia and light sedation so that it is a completely painless. This process only takes 15 minutes and does not require an operation, being hospitalised, stitches or the use of general anaesthesia.

       4. Laboratory fertilization

The retrieved eggs are taken into the IVF laboratory where they are prepared for insemination. At the same time, the semen is activated to improve its fertilization potential. Oocytes and spermatozoids are placed together for several hours within an incubator which provides the ideal conditions for fertilization to take place and the subsequent development of pre-embryos. The number of fertilization eggs will not be known until the next day but the overall fertilization rate is 60%. For this reason several embryos usually develop.

      5. Embryo transfer

The embryo culture stage can last between two and five days. This enables us to observe the embryo development in order to select the ones with the highest quality. Nature will reject the weaker ones. In general, during a longer culture period, there are fewer viable embryos but they are of much better quality than the embryos achieved during a short culture period.

The implantation rate, meaning the percentage of embryos that take hold in the uterus, is generally between 40 and 50%. In order to avoid multiple pregnancies we often propose transferring only one embryo and freezing the rest. The embryos are placed in the uterus through a quick and painless procedure.

Embryo cryopreservation

Any remaining viable embryos are cryo preserved. That is to say, they are frozen to allow for future transfers if pregnancy does not occur after the first transfer and the procedure needs to be repeated or to give the couple the option of having another child at a later date without having to undergo the entire IVF process from the beginning. The pregnancy rate obtained after cryopreservation is 40%.

Having viable embryos does not necessarily mean that a pregnancy will develop. Unfortunately, the implantation rate in human beings is not so high and not all transfers develop into a pregnancy. In most cases it is not possible to know why embryo transfers have not succeeded, because in a natural pregnancy the number of embryos that do not implant is very high. Currently this is the basis of many scientific studies.

Our goal is not to obtain multiple pregnancies but rather to obtain the highest success rate per cycle. Nevertheless, since the embryo does not always implant, in many cases we transfer two or three embryos. Transferring more embryos is not entirely beneficial as there is a risk of multiple pregnancies.


Once gestation has been attained, the pregnancy will develop normally without requiring special controls, except for the usual attention that is paid to highly desired pregnancies. Please note that the possibility of miscarriage, malformations, etc. is the same as for naturally-achieved pregnancies.

If the treatment ends and pregnancy has not been achieved, the Reproduction Committee, represented by the team in charge of the particular case, will re-evaluate the situation in order to advise the patients on the subsequent steps to be taken. For this purpose, we conduct a personal interview with the couple.

The above information may be modified due to the constantly evolving legal and medical changes that occur in Reproductive Medicine and due to the specific characteristics of each case. At Instituto Bernabeu, all our doctors, biologists, nurses, laboratory and administration staff do their best to help each couple achieve our common goal: the birth of a healthy child.