In Vitro Fertilisation

In Vitro Fertilisation (IVF) is an assisted human reproduction technique in which the woman's oocytes are obtained from her ovaries, which have been previously stimulated with hormone treatment, and fertilised in the laboratory with sperm from her male partner to generate embryos which, once they have developed correctly, can be transferred to the patient's uterus or cryopreserved.

FIV

IVF is indicated in the following cases:

• Tubal factor (blocked fallopian tubes)
• Sterility of unknown origin
• Failure of previous inseminations: sterility of unknown cause
• Severe male factor: abnormal semen analysis
• Genetic alteration requiring pre-implantation genetic diagnosis
• Some severe cases of polycystic ovaries

Stages of In Vitro Fertilisation (IVF)

1 - Ovulation stimulation

The woman undergoes hormonal stimulation of the ovaries to achieve oocyte maturation. There are different ovulation stimulation protocols that should be indicated depending on the cause of infertility, the hormonal profile and the age of the patient. Likewise, the dosage of the drugs is also adjusted to each patient's individual profile.

In most cases, the treatment is administered in the form of injections that are given subcutaneously by the patient herself. It is important to have a good number of oocytes, as not all of them will be fertilised and produce a good number of high-quality embryos.

During the ovulation stimulation process, ultrasound scans and blood tests are carried out to monitor the cycle and ensure a good response in terms of the quantity and quality of the eggs we are going to obtain. This stage usually lasts a maximum of about 15 days.

Ovulation-stimulating medication has no significant side effects for the patient. Even so, you may experience fluid retention and/or mild abdominal discomfort. As for risks to consider, basically, ovarian hyperstimulation should be taken into account.

2 - Ultrasound-guided ovarian puncture

Once the eggs have matured in the ovaries, they must be extracted so that they can be fertilised in the laboratory.
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To this end, ultrasound-guided follicular puncture is performed. It is performed under sedation, so it is completely painless.

The follicular puncture usually takes approximately 20 minutes. It is performed in a surgical area, with the collaboration of the gynaecologist who performs the procedure, an anaesthetist, a nurse and the biologists who will collect the oocytes.

The oocytes are aspirated from the ovaries and transported to the laboratory in their own follicular fluid.

After the puncture, the patient remains for a while to recover from the anaesthesia and can then go home, where she is advised to rest for the rest of the day.

3 - Fertilisation

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Once the oocytes are in the laboratory, the sperm sample provided by the male partner or the sample from the sperm bank, if a donor is used, is processed.

There are two forms of fertilisation

• • Conventional insemination, which involves depositing a specific number of sperm next to each egg and allowing fertilisation to occur spontaneously.
  • Intracytoplasmic Sperm Injection (ICSI), indicated in cases of male or female factors that cause us to doubt fertilisation. ICSI involves injecting a single sperm directly into the egg. First, the oocyte is ‘stripped’ of the accompanying granulosa cells to facilitate microinjection, and a morphologically normal spermatozoon is selected for microinjection.

inyeccion

Whenever the male partner has had a vasectomy or the semen sample must be obtained testicular biopsy (Testicular Sperm Extraction - TESE), this step is carried out simultaneously with oocyte retrieval, followed by fertilisation at the laboratory.

After fertilisation, the embryos are monitored in the laboratory. They are supervised by biologists and monitored to ensure their proper development in the initial stages. They are kept in incubators at a constant temperature in culture media suitable for their proper development.

Between two and three days later, they are evaluated and selected for transfer to the patient and/or vitrification. Not all of them develop correctly, so some will stop developing and be discarded for transfer.

In some cases, for various reasons, it is considered appropriate to extend the cultivation of embryos to a more advanced stage of development, known as ‘blastocyst’, and they will be transferred on the 5th or 6th day of development.

4- Embryo transfer

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The patient, who has been undergoing treatment with progesterone since the day of the follicular puncture to promote the embryo's ability to implant in the uterus, goes to the fertility clinic where one or two embryos will be placed in her uterus.

The transfer technique is very simple. It is performed without anaesthesia because it is not painful and is monitored by ultrasound (abdominal ultrasound). A thin catheter is inserted through the vagina and deposits the embryos in a specific location within the uterus where implantation is ideal.

After the transfer, biologists will proceed to vitrify any surplus embryos. The patient remains at rest in the clinic for a period of time and is then transferred to her home, where she is advised to rest for the rest of the day.

In the days that follow, and until the pregnancy test is carried out 13 days later, it is advisable to avoid intense physical exercise. For the pregnancy test, you simply need to go to the centre on the appointed day to have a blood test to determine your β-HCG levels, and a few hours later you will be given the result.