An In Vitro Fertilisation or IVF performed in the natural cycle and without hormonal stimulation for those who are sensitive to medication.


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What does it offer?


The Natural In Vitro Fertilization is ideal for women or couples who do not want to undergo hormonal stimulation to obtain more eggs or those women who have undergone multiple in vitro fertilisation processes and the medication has had adverse effects or they are unable to retrieve more than one or two eggs following stimulation.


In Vitro Fertilisation creates embryos in the laboratory with an egg from the mother and sperm from the male. The embryos generated are finally transferred into the mother’s uterus, where a completely normal pregnancy develops.


The completion of a natural cycle requires a more complicated follow-up for our team and needs the woman to have more follow-up visits to track her natural ovulation. The probability of cycle cancellation due to premature ovulation in these cases is slightly higher than IVF with medication, so our team will never perform egg retrieval in case of suspected or threatened premature ovulation.

Who is it for?

Women who do not want hormonal stimulation

Couples with age-related infertility who retrieve one or two eggs in previous IVF cycles that do not respond to medication

Women or couples in whom inseminations have failed

Female couples


During this first visit, the medical team at Fertty will assess your entire reproductive medical history and review all tests performed or request new tests if they have not been ordered previously (FSH on the third day of the cycle, Anti-müllerian Hormone or Antral Follicle Count by ultrasound). All this will help make it possible to design an exclusive personalised treatment.



When you start your period, you contact our team who will give you an appointment for the first ultrasound check-up. This process lasts between 8 and 14 days, during which time the Fertty team will perform ultrasound checks and, occasionally, analytical controls of E2 or progesterone. Once the follicles have reached an appropriate size an hCG injection is used to mature the eggs and induce ovulation and a GnRh antagonist injection is used to prevent premature ovulation and be able to accurately time the oocyte retrieval.



36 hours after the HCG, we performed the aspiration of the eggs from the ovaries. It involves making a small puncture through the vagina. The medical team performs an ultrasound scan in which they will have attached a needle to the ultrasound machine and, through that fine needle, all the eggs available in that cycle will be aspirated. At the same time, you will be mildly sedated for your comfort. The process takes about 20 minutes.

At the same time the partner will give a fresh semen sample. If this is not possible, the sample of donated semen selected for the process will be checked again. Before leaving the centre, you will be informed of the number of eggs retrieved and you will be instructed to start taking the progesterone that prepares the uterus for gestation. The embryo transfer will take place 3 to 5 days later.



Fertty’s team of biologists unites the eggs with the sperm so that fertilisation occurs spontaneously. In cases where there are few sperm or fertilisation failure is suspected, a sperm is injected into the egg. This process is called Intracytoplasmic Sperm Injection (ICSI).



Our embryologists regularly monitor the embryos for about five days to check that they are developing properly and that they are dividing adequately. The speed of division, the number of cells and their symmetry allows our team to select the highest quality embryos so that pregnancy can occur. Couples with genetic diseases, repeated miscarriages or age-related infertility may consider genetic diagnosis of embryos to select the healthiest embryo.



Three to five days after the puncture the embryo or embryos are transferred into the mother’s uterus. This simple procedure is performed in the laboratory, using a catheter to introduce them through the cervix. This technique does not cause any pain and does not require anaesthesia, so the woman can leave the clinic within a few minutes and go about her normal life from the next day onwards. Pregnancy takes place if the embryo engages in the endometrium. The embryos that have not been transferred are frozen to allow for future implantation.



To help implantation occur, you will continue to take the progesterone for a further two weeks and a few days after the embryo transfer, we will perform a blood pregnancy test. Once pregnancy is confirmed, you will continue to take progesterone for two weeks until your gynaecological team confirms the pregnancy by ultrasound. If the pregnancy has not been confirmed, you can decide with your gynaecologist to start a frozen embryo transfer or repeat a new cycle of In Vitro Fertilisation.

In Vitro Fertilisation is the most effective technique to obtain a baby.
During the phase of Embryonic Development, the Fertty team of biologists will inform you day by day of its evolution and care.


  • Cycle programming
  • Personalised follow-up of every medical process
  • Serial ultrasound checks
  • Egg retrieval + operating theatre costs
  • Seminal Sample capacitation and preparation
  • Oocyte Fertilisation – IVF / ICSI
  • 1st embryo transfer
  • β-hCG pregnancy test and 1st ultrasound pregnancy test


  • Follow-up visit
  • SARS COVID 19 antigen test
  • Embryo culture
  • Medication for ovulatory discharge
  • Anaesthetics
  • Sedation in embryo transfer
  • Donor sperm
  • Donor sperm + matching
  • Sperm freezing
  • Genetic Compatibility Test (GCT)
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