In Vitro Fertilisation is the most effective assisted reproduction technique with success rates of around 40%, well above those of artificial insemination (20%).

IVF is used for both couples who have fertility problems and single women who have decided to have a child through sperm donation.
With the appropriate procedures, the eggs and sperm cells are obtained separately and the fertilisation process is performed in the laboratory. The embryos obtained are subsequently transferred to the uterus of the mother, where the pregnancy process will continue.

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reproducción asistidareproducción asistidaCauses of infertility

Causes of infertility

Until a few years ago, the responsibility for infertility in a couple was distributed equally between men and women at 50%, but, according to some studies, this is changing and men are the ones who are presenting a higher rate of infertility. Factors such as stress, smoking and pollution have resulted in a decrease in the quality of semen.

In any case, we can make the following distribution:

  • 30% due to the woman.
  • 30% due to the man.
  • 20% due to a combination of causes attributable to the man and to the woman.

Infertility in women

    • Age.- While in the first few years of sexual maturity the vast majority of women are fertile, when the menopause approaches only 5% can conceive naturally. The change in female fertility according to age would be as follows:
      • Between 20 and 24 years-old 86%

      • Between 25 and 29 years-old 78%

      • Between 30 and 34 years-old 63%

      • Between 35 and 39 years-old 52%

      • Between 40 and 44 years-old 36%

      • Between 45 and 49 years-old 5%

    • Ovulation problems.- This is the first problem that women have when it comes to infertility (35%). We may be talking about "dysovulation", i.e. irregular ovulation, or about lack of ovulation "anovulation".
      The causes can be very varied:
      • Polycystic ovaries.- These are very common.
      • Hormonal disorders.- Which may be due to thyroid problems, sudden weight changes, anorexia and even stress, among others.
      • Dysfunction of the hypothalamus or the pituitary gland.- The instruction for ovulation that should arrive does not do so due a malfunctioning of these.

    • Cancer and other conditions

    • Blocked fallopian tubes.- After ovulation disorders, this is the next most common infertility problem in women (15%). The blockage can be due to:
      • Infections.
      • Problems with previous pregnancies.- It is common, for example, when a woman has suffered an ectopic pregnancy or when she has had an abortion.
      • Use of an IUD.- It could be a side effect.

    • Endometriosis: This is a condition of the endometrium, the mucous membrane that lines the uterus. When this membrane develops outside of its natural environment, the uterus, it can result in multiple disorders, including infertility (it represents 5% of infertility problems in women).

      Endometriosis can invade fallopian tubes and ovaries, among other organs, impeding their normal functioning.

    • Other.- There are multiple other causes which result in a woman not being able to conceive, such as uterine fibroids, myomas, venereal diseases, etc.

Infertility in men

    • Testicular conditions.- These represent between 30 and 40% of infertility problems in men. The semen is of poor quality, with the number of sperm cells being low, their motility is reduced, etc.

      The testicles can be affected by:

      • Varicocele.- Veins in the scrotum dilate, obstructing the flow of blood, increasing testicular temperature and harming the sperm production.
      • Physical injuries

      • Hormonal problems.- Alterations in the thyroid, androgen insensitivity, hyperprolactinaemia: an overproduction of the hormone prolactin which is produced in the pituitary gland, etc.
      • Venereal diseases.
      • Other.- Radiotherapy, chemotherapy, diabetes, side effects of medications, etc.

    • Ejaculatory duct obstruction.- This blockage can happen due to various problems in the testicles, the epididymis, the urethra, the prostate or in the vas deferens:
      • Cysts and fibrosis
      • Cryptorchidism.- The testicles do not descend towards the scrotum.
      • Illnesses.- Such as meningitis or mumps that can cause obstruction of the vas deferens.
      • Vasectomy.- The vas deferens have been sectioned voluntarily.

    • Ejaculation problems:
      • Premature ejaculation
      • Erectile dysfunction.- The man is not able to have an erection.
      • ERetrograde ejaculation.- Instead of semen coming out through the urethra, it is sent to the bladder.
reproducción asistidareproducción asistidaStudy of the couple

Study of the couple

When a couple comes to our In Vitro Fertilisation unit, information is gathered about all clinical aspects that may be related to their infertility problem. The couple will be looked after by a multidisciplinary team made up of gynaecologists, biologists and psychologists specialising in assisted reproduction who will advise and give information, in their particular field, about the entire process.

To determine the feasibility of in vitro fertilisation, it will be necessary to carry out a series of tests.


Necessary tests in women:

    • Ultrasound scan.- An ultrasound scan will be done to check that the ovaries are suitable, with no cysts, and that the uterus is in a position to house the embryo, i.e. that it does not present deformities, that the membrane that lines it (endometrium) does not contain polyps, etc.

      This ultrasound scan should be performed during the first few days after the menstrual cycle.

    • Analysis of hormones.- Where the parameters LH, FSH, PRL and 17β-Oestradiol will be checked. The anti-Müllerian hormone is sometimes also checked.

    • Analysis of viral diseases.- The parameters HIV antibodies, HBsAg, RPR and hepatitis C antibodies will be checked.

If the cause of the infertility has not been identified with the above tests, the doctor may be able to indicate other alternative tests:

    • Karyotype.- Blood is drawn to obtain the karyotype. This is done to see if there is any abnormality in the chromosome pattern that may be the cause of the reproductive problems.
    • Hysteroscopy.- A small camera is inserted into the uterus to check if there are polyps and fibroids. If so, it would be possible to insert with the camera microsurgical instruments with which to operate on them.
    • Other.- Other tests may be indicated, such as a Hysterosalpingography (HSG).

Once it has been decided to proceed with In vitro fertilisation (IVF)...

    • Catheter test.- It is necessary to know which catheter will be the most suitable for the insertion of the fertilised egg before its implantation. For this, the gynaecologist does a test using an ultrasound scan to take measurements and determine the way in which it is going to be placed.

Necessary tests in men:

    • Spermiogram.- This is an analysis of the semen in which the number and function of the sperm cells will be checked. In addition, other significant factors for fertility will be assessed, such as the pH, viscosity, coagulation and agglutination of the semen.

After checking the spermiogram, some complementary tests may be ordered:

    • Analysis of hormones.- Unlike that which is carried out on women, it is usually only FSH which is measured to check testicular function.
    • Analysis of viral diseases.- This is similar to that carried out in women, HIV antibodies, HBsAg, RPR and hepatitis C antibodies.
    • Testicular Echo-Doppler.- With this, it is possible to observe if the testicles have cysts, varicose veins or other abnormalities that can affect fertility.
    • Karyotype.- Blood is drawn to obtain the karyotype. This is done to see if there is any abnormality in the chromosome pattern that may be the cause of the reproductive problems.
    • FISH test in semen.- This test is usually only carried out when others have failed. This makes it possible to observe if there are abnormalities in the chromosome number of sperm cells.
    • Other.- Other tests that determine the cause of male infertility may be indicated, such as a testicular biopsy, the CFTR gene test, etc.
reproducción asistidareproducción asistidaIVF Procedure

IVF Procedure

Once the study of the couple has been done, checking the feasibility of in vitro fertilisation and the legal terms have been approved, the IVF procedure itself starts.

  • Ovarian stimulation:

EIn this first phase, which lasts a couple of weeks, a series of hormones will be administered every day to the woman in an injection normally via the subcutaneous route.

With these extra hormones, it is sought to achieve a greater development of the follicles containing the eggs, and, therefore, to obtain a greater number of eggs. The process is observed and monitored through vaginal ultrasound scans and blood tests in which the level of oestradiol is controlled. If this step is not carried out, the chances of pregnancy would fall below 5%.

  • Obtaining semen and eggs:

    • El semen: It should preferably be obtained on the same day that the eggs are extracted, although it would also be possible to have it frozen beforehand. About three days of sexual abstinence beforehand are recommended.

      The semen is deposited in a sterile container and is delivered immediately to the laboratory, which processes it within one hour.

    • Eggs: Once they have matured, they are extracted through an ultrasound-guided follicular puncture. The procedure, which lasts about 20 minutes, is performed in an operating theatre under sedation.

      The extracted eggs are taken to the laboratory together with their follicular fluid.



  • Fertilisation in the laboratory:

        There are two ways of carrying out fertilisation in the laboratory:

    • Conventional fertilisation: This consists of incubating at 37ºC a culture of about 100,000 sperm cells selected for their motility together with the eggs obtained.

    • Sperm injection: An expert biologist will inject one of the sperm cells into the cytoplasm of the egg using a microscope. This is the most advanced technique.

      The day after the fertilisation attempt, it will be possible to observe under the microscope if this has been successful. The egg should have two pronuclei. After 48 hours, an embryo will be observed with several cells. One of the 4 cells that are regular will be considered as good.

      On the fifth day, after successive cell divisions, the blastocyst will have formed. This will be composed of an inner layer that will form the embryo and an external layer that will be the future placenta. Around 60% of the embryos reach this blastocyst phase.

      This is the point when one or several embryos may be vitrified (frozen) for future attempts.

    • Embryo transfer.- On the fifth day a blastocyst is selected (two in exceptional cases), the one in the best condition. This embryo is loaded into a catheter and, using ultrasound, it is guided through the vagina to the uterus, where it will be deposited at approximately one centimetre from its base. Anaesthesia is not necessary for this operation.

      Beforehand, progesterone therapy will have been administered to improve the conditions for implantation in the uterus.

      After removing the catheter, the woman must remain lying down for about 5 minutes, with her legs bent and at rest.

      A pregnancy test will be done 13 days later by means of a β-HCG blood test.