Some of the working instruments of an embryologist at a fertility clinic laboratory include glass pipettes, sterile tubes and petri dishes. One of the places that patients usually do not have access to is the laboratory in which life is created. This is due to the environmental conditions that need to be met inside the lab. This may be the reason as to why this part of the clinic generates most interest among IVF-Life patients. With this interview in which Leonor Ortega, Director of the IVF-Life group laboratories explains what really happens inside the laboratory of a fertility clinic, we want to figuratively open up our laboratories for you without jeopardising any of our work processes. The patient has already followed the ovarian stimulation protocol and the important day of the egg retrieval and egg retrieval has finally arrived. This is without doubt a very important step in the fertility treatment.

How is the egg retrieval carried out?

The eggs are obtained through follicular puncture which is performed in the operating theatre by a gynaecologist, assisted by a nurse. Using an ultrasound machine, follicles of a certain size (larger than 16 mm) are punctured with the puncture needle and absorbed, one by one. The liquid obtained is placed in a sterile tube and taken to the IVF-laboratory. It has to always be kept at a constant temperature of 37ºC. The contents of these tubes are then placed onto a 90 mm petri dish in the laboratory of our fertility clinic. Using a magnifying glass and a sterile glass pipette the cumulus-corona-ovocyte complexes are passed to another petri dish. The oocytes are cleaned of any remains of cells and blood, to leave them as clean as possible and then left in the petri dish for another hour to be able to adjust to the new environment and stabilise it. Not only the oocytes are an important factor for a successful fertilisation, we are also aware that the male factor contritbutes to 40% of cases of infertility.

What is a sperm preparation?

The semen preparation is an important process in all Assisted Reproduction treatments. Through the sperm preparation we are able to obtain the best spermatozoa which we will use to fertilise the egg. In addition to the semen sample collection, we  also need to perform a centrigutation process as this is the most appropriate means to carry out the sperm washing. Density gradient centrifugation and swim-up are the two preparation techniques. Depending on the sperm conditions, we would choose one or the other technique to carry out the sperm preparation.

What is the environment inside an IVF laboratory of a fertility clinic like in order not to disturb the embryo development?

It is very important to have stable temperature and humidity conditions in the IVF-laboratory. We use positive pressure ventilation to prevent contaminating agents from entering the laboratory. Furthermore, no air enters directly from outside as the air inside the laboratory is purified by various filters. Our laboratory is also equipped with an air purification tower that is operating 24 hours a day. We take further precautions by not using perfume, deodorant nor body lotions with strong odour as to not create volatile compounds that could interfere with the embryo development. The same measures are taking to avoid use of make-up, blush, mascara, etc. that would pollute the air.

Workstation: What does it consist of?

The work station is integrated in a laminar flow cabinet that is equipped with a heated surface so that the gametes and embryos are always kept at a temperature of around 37ºC. All necessary material for each process is found in these work stations, petri dishes, media, pipettes which we use to take the embryos and oocytes, etc. Another key point of a fertility treatment, the fertilisation of the egg with sperm, takes place within the IVF-laboratory.

Conventional IVF or ICSI? What is the difference?

In the in vitro fertilisation laboratory we have two assisted reproduction techniques for the fusion of the oocyte and the sperm. IVF, in vitro fertilisation. The goal of this assisted reproduction technique is to achieve the most natural fusion of the sperm and egg possible. This is done following the egg retrieval by placing the oocytes with its culture medium and a specific amount of about 150,000 spz/ml together on the petri dish. The petri dish is then kept inside an incubator with a specific and constant concentration of gases and temperature. The next day we take and clean these oocytes before selecting those that were fertilized correctly (appearance of pronuclei). To be able to follow their development individually, the fertilised eggs will then be left in the culture. This technique arose at the beginning of the 1980s when egg retrievals began to be performed to help couples who were unable to achieve a pregnancy after intrauterine insemination due to limitations of the technique, such as ovarian obstruction. But not all problems such as failure of fertilisation and cases with severe male factor can be solved, as this technique also has its limitations. ICSI, cytoplasmic microinjection. In this technique the spermatozoon is introduced into the egg in an artificial manner to facilitate the fertilisation. In 1992 Palermo described the first case of cytoplasmic microinjection with a twin birth.

When to use  ICSI ?

• Infertility caused by female gamete: when only few oocytes were obtained, poor oocyte quality, previous failure of IVF fertilisation, advanced age.
• Infertility caused by male gamete: low sperm motility, low sperm concentration, when it is needed to resort to a testicular biopsy.
• Mixed causes; when there is a combination of several causes.

Both techniques are equally effective and have equally high pregnancy rates. The chances of achieving a pregnancy depends more on the age and quality of the eggs themselves than on the method used to fertilize the eggs. The embryo development phase begins once fertilisation has taken place and the correct development can then be followed within the incubator.

How important is the incubator for the embryo development?

As it is where the oocytes are left after the microinjection and where they will “live” during the first six days, the incubator plays a fundamental role in the embryo development. The correct development of the embryos inside the incubator is ensure by determined temperature and CO2 and O2 levels. Is the incubator equipped with a time-lapse system, it offers the advantage of being able to observe the embryos without removing them from the incubator. This way we don’t need to interrupt their conditions during the entire embryo development.

What is culture media?

A culture medium is a mixture of organic and inorganic compounds that tries to imitate the oviductal fluid. The embryos stay in this culture medium throughout their entire embryo development. It provides the embryos with the necessary nutrients to be able to develop correctly.

Selecting the best embryo for the transfer; How important is the embryologist’s judgement?

The embryologist’s judgement is the most important of all since they are responsible for bringing together all the morphological, kinetic and genetic criteria in order to make the best selection. We have the morphological classification evaluated by the embryologist each day of the embryo development. Together with this and through coadjutants like the time of division, reverse or direct divisions, application of algorithms, etc. we can “recategorize” the embryos. The selection is much more detailed if we have additional genetic information of the embryo. In that case, to select the best one for the transfer, we only focus on those embryos that are genetically normal. However, one thing that is of great concern to patients is wanting to know what happens to their samples in the IVF laboratory.

How do you make sure that no sample is lost in the laboratory?

Traceability of the samples is crucial in IVF-laboratories. In every laboratory of our clinics in Alicante, Madrid or San Sebastian we have an integrated traceability system. Through this system we can trace every step of the process from beginning until the end. Without checking the previous step, we cannot carry out the following. All the petri dishes, freezer supports and tubes are double-labelled, manually and through a system. This way, it is almost impossible to lose or confuse samples. In some more delicate processes such as transfers or embryo biopsy we carry out double checks in addition to this system. We also have a computer system in which we record the location of the samples such as oocytes, embryos or semen in our databank in order to locate them quickly. This location is then also documented on paper in the laboratory protocol for double control. At our fertility clinic, we know the stress and anxiety our patients go through. This is the reason why we ensure our communication is constant, fluid and empathetic. Perhaps the laboratory is one of the departments that communicates with patients most frequently since under the care and professionalism of our team are the embryos of our patients.

What is the communication with your patients like?

At any stage of the treatment communication with patients is key. But after the egg retrieval or gamete donation, when the embryos start their cycle in the laboratory, this communication becomes even more important. When patients make their first visit to our clinic, they usually want to get to know the medical team and how we work. We are always open to resolve any kind of doubts patients have during this first contact with our fertility clinic. If you have any doubts during your stimulation, we are at your disposal to resolve them. Also, after the microinjection, a key point in the assisted reproduction process, it is crucial to give clear information so that our patients understand what is happening at all times. We communicate with our patients daily until the embryos reach day 6. Depending on their preference to receive the information, we contact our patients first thing in the morning after checking on the embryos, via an e-mail or call. This communication includes the following information:

• How many embryos were fertilized correctly.
• How they are developing.
• How many are still developing.
• How many embryos are of good quality.

On day 5 and day 6 we inform our patient about how many embryos we have been able to vitrify or, if a transfer is planned, we inform you, right before the transfer, of the result of the cycle. Not all patients prefer to know how the development of their embryos is going as it creates too much anxiety and stress for them, but rather wait until the end. We leave this decision up to our patients. We are convinced, that by having such a great communication with our patient we can include them in the procedure taking place in the laboratory and that it helps them to understand the process and development. As you can tell, a day within a laboratory of our fertility clinic is complex, meticulous and exciting. But thanks to the most advanced medicine and the almost “artisan” work of our embryologists we can help men and women fulfill their dream and create something amazing: a new life.