Sterile tubes, glass pipettes or petri dishes are the working instruments of an embryologist in a fertility clinic laboratory. This place, where life is created, is the only one to which patients usually do not have access to, given the necessary environmental conditions of the laboratories. And perhaps for this reason it may be one of the parts of the clinic that generates most interest among IVF-Spain Madrid patients.
We wanted to open our laboratory, figuratively and without jeopardising any of the work processes, through this interview with Leonor Ortega, Director of the IVF-Spain laboratory, who will explain what really happens inside the laboratory of a fertility clinic.
The patient has already followed the ovarian stimulation protocol and the long-awaited day of the ovarian puncture and egg retrieval has arrived. This is without doubt a very important step in the fertility treatment.
What is the egg retrieval process like?
The oocytes are obtained through follicular puncture. This follicular puncture is performed in the operating theatre by a gynaecologist, assisted by a nurse. Using an ultrasound machine, follicles of a certain size are punctured with the puncture needle and follicles larger than 16 mm are absorbed, one by one. The liquid obtained is placed in a sterile tube and taken to the in vitro fertilisation laboratory, always maintaining a constant temperature of 37ºC.
In the laboratory of our fertility clinic, the contents of these tubes are placed onto a 90 mm petri dish. Using a magnifying glass and a sterile glass pipette the cumulus-corona-ovocyte complexes are passed to another petri dish where they are cleaned of any remains of cells and blood, to leave them as clean as possible. To be able to adjust to the new environment and stabilise the oocytes are left in the petri dish for an hour.
We know that it is not only the eggs that are important for a successful fertilisation to take place, as we also know that the male factor intervenes in 40% of cases of infertility.
How is the sperm preparation carried out?
Semen preparation is a basic process in Assisted Reproduction treatments.
Through the sperm preparation we obtain the best spermatozoa which we will use to fertilise the oocyte. For this process we need, in addition to the semen sample, a centrifuge and the appropriate means to carry out the sperm washing.
There are two preparation techniques: density gradient centrifugation and swim-up. Depending on the seminal conditions, we would choose one or the other.
What environment is needed in the laboratory of a fertility clinic in order not to influence the embryonic development?
In the IVF-laboratory it is crucial to have stable temperature and humidity conditions. With regard to ventilation, we use positive pressure to prevent contaminating agents from entering the laboratory. Furthermore, the air inside the laboratory is purified by various filters; it is not air that enters directly from outside. Our laboratory is also equipped with an air purification tower that is operating 24 hours a day.
In addition, we take further precautions by not using perfume or deodorant with odour, nor do we use body lotions with strong smell so that there are no volatile compounds that could interfere with the embryonic development. The same is done with make-up, blush, mascara, etc. to avoid any particles in the air.
What is a workstation and what does include?
The work station is always 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.
In this work station we have all the necessary material for each process. The petri dishes we use, the media, the pipettes with which we take the embryos and oocytes, etc.
Another key point of a fertility treatment takes place within the IVF-laboratory. This involves the fertilization of the egg and sperm.
What is the difference between conventional IVF and ICSI?
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, is an assisted reproduction technique that consists of placing the male and female gamete in a petri dish in the laboratory so that the sperm can fuse with the egg in the most natural way possible.
For this, the oocytes are placed on the petri dish with its culture medium following the ovarian puncture and a specific amount of about 150,000 spz/ml is placed on the petri dish to swim in the medium.
This petri dish is kept in an incubator with a specific and constant concentration of gases and temperature. On the following day we take and clean these oocytes before selecting those that were fertilized correctly. The correct fertilization can be observed by the appearance of pronuclei. After this, the fertilized eggs will be left in the culture to be able to follow their development individually.
This technique arose at the beginning of the 1980s when ovarian punctures began to be performed to help those couples who, with artificial insemination, were unable to achieve pregnancy due to the limitations of the technique, such as ovarian obstruction.
But this technique also has its limitations and does not manage to solve every fertility problem, such as failure of fertilisation and cases with severe male factor.
ICSI, cytoplasmic microinjection, is a technique in which the spermatozoon is introduce into the egg in an artificial manner, facilitating fertilisation. In 1992 Palermo described the first case of cytoplasmic microinjection with a twin birth.
When should the ICSI technique be implemented?
- Causes of infertility due to the male gamete, low sperm motility and low sperm concentration and when it is needed to resort to a testicular biopsy.
- Causes due to the female gamete: when only few oocytes were obtained, poor oocyte quality, previous failure of IVF fertilisation, advanced age.
- Mixed causes; when there is a combination of several causes mentioned above.
With regard to the effectiveness of the techniques, they are both equally effective and have equally successful pregnancy rates. The probability of achieving a pregnancy depends more on the age and quality of the eggs themselves than on how they are fertilised.
Once fertilisation has taken place, the embryonic development phase begins. The correct development can then be followed within the incubator.
What role does the incubator play in the embryonic development?
The incubator plays a fundamental role in the embryonic development, as it is where we place the oocytes after the microinjection and where they will “live” during the first six days.
Inside the incubator determined temperature and CO2 and O2 levels ensure the correct development of the embryos.
If our incubator is equipped with a time-lapse system, it offers the advantage of being able to observe the embryos without removing them from the incubator and, therefore, not needing to interrupt their conditions during the entire embryonic development.
What characteristics should a culture medium have?
A culture medium is a mixture of organic and inorganic compounds that tries to imitate the oviductal fluid and in which the embryos stay throughout their embryonic development.
These media provide the embryos with the necessary nutrients to be able to develop correctly.
How important is the embryologist’s judgement when selecting the best embryo for the transfer?
The embryologist’s judgement is the most important of all. The embryologist is responsible for bringing together all the morphological, kinetic and genetic criteria in order to make the best selection.
On one hand, we have the morphological classification evaluated by the embryologist each day of the embryonic development and together with this we can “recategorize” the embryos through coadjutants like the time of division, reverse or direct divisions, application of algorithms, etc.
If we have additional genetic information of the embryo the selection is much more detailed, since, we are only going to focus on those embryos that are genetically normal to select the best one for the transfer.
One aspect that is of great concern to patients is knowing what happens to their samples in the IVF laboratory.
How is it ensured that no sample is lost in the laboratory?
In the in vitro fertilization laboratories the traceability of the samples is very important.
In every laboratory of our clinics (Alicante, Madrid or San Sebastian) we have an integrated traceability system through which we trace every step of the process “from where it comes to where it goes”.
We cannot carry out the following process without checking the previous one. All the petri dishes, tubes and freezer supports are double-labelled, manually and through a system, so that losing or confusing samples is impossible.
In addition to this system, we carry out double checks in some more delicate processes such as transfers or embryo biopsy.
And when it comes to storing the samples (embryos, oocytes and semen) we have a computer system in which we record the location of the samples in our databank in order to locate them quickly. This location is 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. Therefore, our communication is constant, fluid and empathetic. The laboratory, perhaps, is one of the departments that needs to communicate with the patient the most, since under its care and professionalism are the embryos of our patients.
How is your communication with patients?
Communication with patients is very important at any stage of the treatment, but when the embryos start their cycle in the laboratory, after the ovarian puncture or gamete donation, the communication becomes even more important.
At our clinic we talk about first contact when patients come to make their first visit to our clinic so that they can get to know our staff and our work. If you have any doubts during your stimulation, we are at your disposal to resolve them.
After the microinjection, a key point in the assisted reproduction process that began months ago, it is very important to give clear information so that our patients understand what is happening at all times.
We communicate with our patients daily. First thing in the morning after checking on the embryos, we send them an e-mail or call them, depending on their preference to receive the information.
Until the embryos reach day 6, we inform our patients daily about how their embryos are developing. In this information we include:
- 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 you 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.
We believe that through this type of communication with our patient we can include them in the procedure and that it helps them to understand the process and development.
There are times when patients prefer not to know how the development of their embryos is going but to wait until the end, as it creates too much anxiety and nervousness for them. We leave this decision up to our patients.
A day within a laboratory of our fertility clinic is complex, meticulous and exciting. Thanks to the most advanced medicine and the almost “artisan” work of our embryologists we can help create what really matters: a new life.
You can consult your case and learn about new fertility methods that are completely suitable for you through this module.