FERTILIZATION
IN VITRO

OVARIAN STIMULATION

One of the reasons why the probability of pregnancy is increased through In Vitro Fertilization is to have more eggs in the same cycle, since the process is optimized by generating more embryos that we can better select to transfer to the maternal uterus and give rise to a healthy baby at home with more success.

In order to have more than one egg, which is what would be usual in a natural menstrual cycle, hormones are administered that act on the ovary. The doses used must be individualized based on several parameters, such as body mass index (BMI), age of the woman, first phase hormonal determinations, ovarian morphology (number of preantral follicles), response to stimulation in previous cycles if any, and the experience of our professionals.

The careful control of ovarian stimulation requires several ultrasound controls (4 or 5) to properly monitor the response achieved in each case. The stimulation process usually lasts between 8 and 12 days. When it is verified that the hormonal levels and the number and size of the follicles are as desired, a final medication is administered to trigger the maturation of the eggs using a hormone called human chorionic hormone (HCG).

EGGS EXTRACTION

The extraction of the eggs or follicular puncture, is carried out in the outpatient minor surgery operating room of the Center itself, under sedation, by means of transvaginal ultrasound control, about 36 hours after the administration of the HCG. The extraction of the eggs is carried out by puncturing the mature follicles and subsequent aspiration of the follicular fluid where the egg should be found. The person responsible for this process is the same gynecologist specialist in fertility who is the one who carries out the technique.

The average duration of this intervention is around 15-20 minutes and is performed with anesthesia (deep sedation) to avoid discomfort to the patient and controlled by one of the Center’s anesthesiologists who will monitor the patient at all times.

The woman’s recovery is rapid, as after 1 or 2 hours, she is discharged home.

At the same time that the operation is being performed in the operating room, the team of biologists is looking for the extracted eggs so that they can be stored in incubators and continue the in vitro fertilization process with them. That is why, when the patient wakes up, she can already know the number of eggs that have been obtained.

IN VITRO FERTILIZATION LABORATORY

Identification and collection of eggs

The follicular fluids obtained in the puncture are taken to the In Vitro Fertilization Laboratory where all the eggs are located and collected while the gynecologist is performing the egg extraction. These are placed in plates with an appropriate culture medium, duly identified and numbered inside the incubator. This is one of the entry points for the traceability control of the eggs, which is controlled by the Witness security system. The incubators maintain them in an appropriate environment in terms of temperature, humidity, proportion and purity of gases.

Semen preparation

In the Andrology Laboratory, the sperm sample will be processed with the most appropriate Sperm Conditioning Technique depending on the quality, which allows us to select and isolate sperm with better mobility, morphology and/or lower DNA fragmentation rate. This is the other entry point for sperm traceability control, which is controlled by the Witness system.

Fertilization Technique

The next step is to facilitate the fertilization of the eggs and sperm. There are mainly two methods to facilitate fertilization:

Conventional Fertilization : is the procedure by which the eggs that are still inside the cumulus (group of cells that surround the egg) are placed in the same medium with the previously treated sperm with the intention that they will carry out fertilization spontaneously. To perform this technique, a minimum concentration of sperm with good mobility of 100,000 sperm per milliliter and per egg is required.

ICSI ( Intra Cytoplasmic Sperm Injection): consists of directly introducing a sperm into a mature egg through micromanipulation. Embriogyn’s teams together with the high training and experience of our embryologists allow fertilization rates of around 75% to be achieved in most cases. Thanks to this technique, only one motile sperm is needed for each mature egg, therefore, this technique can be applied in very low quality sperm samples. (testicular biopsy)

Fertilization assessment

The validation that fertilization has occurred correctly is carried out 16-20 hours after ICSI or Conventional Fertilization. For fertilization to occur, it is a sine qua non condition that the embryo presents its own structures, which are two pronuclei, one that comes from the egg and the other from the sperm. Any variable or the absence of these structures means that correct fertilization has not been carried out and therefore discards these eggs to continue the process.

Embryo culture, the EMBRYOSCOPE

The Embryoscope is a time-lapse culture system that provides us with continuous images of embryos. Since 2011, Embriogyn has joined the reproductive medicine revolution by applying this technology to all patients at the center, which has allowed us to improve pregnancy rates by around 15-20%.

The fertilized eggs, now embryos, are kept in culture in the Embryoscope incubator for between 3 and 6 days before being placed back into the mother’s uterus. This embryonic culture allows the in vitro development of the embryos and allows us to continuously assess the evolution of each one of them and have the information necessary to choose the best ones to be transferred to the mother’s uterus. This information that the Embryoscope provides us is shared with our patients, allowing each one to see their own embryos, thus providing confidence and transparency to the entire process that is being carried out in the in vitro fertilization laboratory, in addition to a higher degree of knowledge and understanding of the evolution of the embryos.

EMBRYO TRANSFER

The ideal time to return the embryos to the mother’s uterus is decided on a case-by-case basis. Depending on many factors such as the characteristics of the embryos, the couple’s medical and reproductive history, the embryologist advises the most appropriate time for transfer (usually on the third or fifth day of embryonic development).

The transfer is a simple and painless procedure, which usually does not require anesthesia. With the help of a very thin catheter, the embryos are deposited in the fundus of the uterus. This process is monitored by abdominal ultrasound.

Currently, between 1 and 2 embryos are transferred, in consensus with the couple and the medical board that assesses the individual history of each case in order to obtain the greatest probability of pregnancy while minimizing the risk of multiple pregnancy.

On some occasions, the transfer of fresh embryos may be discouraged for various reasons, which is why all the embryos obtained in that treatment are frozen to be transferred later in a cryotransfer process.

VITRIFICATION OF THE REMAINING EMBRYOS

Once the transfer of the selected embryos has been carried out, the remaining good quality embryos are frozen, in order to preserve their potential to be transferred at a later date.

The technique used to freeze embryos is vitrification, which gives very high survival rates and the same probability of pregnancy as fresh embryos.

Embryo freezing is therefore a very good fertility preservation system, although one must be very strict in freezing only those embryos that really have fertile potential to give real expectations to parents who later want to use their frozen embryos.

PREGNANCY TEST AND ULTRASOUND

Once the technique is complete, you will rest for a few minutes, we will give you the instructions to follow and we will set a date to take the pregnancy test with the first urine of the morning approximately 14 days after the egg extraction. During this period, we recommend living a completely normal life, maintaining your usual routines and avoiding only high-intensity efforts. We will also give you some guidelines to reduce the stress of waiting and transform it into a positive and empowering attitude to live it in the most natural way possible.

Three weeks after the positive result, an ultrasound will be performed to check the viability of the pregnancy. This ultrasound is performed at week 6-7 of pregnancy, where the gestational sac and yolk sac of the embryo can be seen with a heartbeat. From here on, this pregnancy is like any other and requires the normal monitoring and controls of a pregnancy and together we can celebrate success!