Watch the webinar in which Elisa Moya Gutiérrez, an embryologist from UR Vistahermosa, is discussing different techniques to improve IVF results in patients with previous IVF failures.
Elisa Moya Gutiérrez started her talk by explaining that even if the number of embryos is high, very often the quality is not good, and this can lead to implantation failures o miscarriages. Laboratory techniques are constantly being improved and with this better selection of the embryos and even better development. Some of those techniques have increased pregnancy effectiveness by 20-30%.
IVF procedure
The basic procedure for IVF treatment includes the appointment with a gynaecologist specialising in IVF, then the diagnosis of the specific case because every case is different and needs a different protocol. When the diagnosis is made and the treatment protocol chosen, it is time for ovarian stimulation. It lasts approx. 10 or 15 days of medication, the doctors try to increase the number of eggs produced in the ovary, so instead of having one egg in one cycle, they can obtain more so that the chances of pregnancy will be higher. The patient has to come for ultrasound control around 2 or 3 times during this process until the eggs inside the ovaries are mature. Then the eggs will be collected in the egg retrieval process, which is a procedure where the gynaecologist takes the eggs from the patient under sedation. It lasts around 20 minutes, then the eggs will be selected by the embryologist and lab. All the eggs are put in the incubator with a specific media until the sperm is ready because the sperm sample must be prepared also in the laboratory using a sperm capacitation technique.
Depending on the quality and quantity of the sperm, the embryologist will decide if it’s better to do a conventional IVF or ICSI fertilization. Once the fertilization is done even with conventional IVF or ICSI, the embryos are created the next day, then the embryologists watch ass the embryos are developing every day in the laboratory and will classify them accordingly.
If there is a low number of embryos, less than 3, it is recommended to have a culture of 3 days and then do the embryo transfer, but if there are more embryos than 3, it is recommended to take them to day 5 and do a better selection and do the embryo transfer. The embryos that are transferred have the best morphology or classification and in Spain, for example, a maximum of 3 embryos can be transferred, however, this is not a common practice. The recommendation is to do a single or double embryo transfer most of the time.
MACS (Magnetic Activated Cell Sorting)
The seminal quality and its influence on embryo development is a crucial factor when it comes to achieving pregnancy, since it affects both fertilization and subsequent embryo quality. There are some cases in which spermatozoa that have been prepared in the laboratory, fertilize their oocytes correctly, but after 3 days of embryo culture, these embryos begin to lose their quality. This happens because the sperm DNA begins to express itself on day 3 of the embryo culture, so to prevent this from happening, the MACS technique can be used. It’s Magnetic Activated Cell Sorting, it’s an immunomagnetic technique allowing the selection of those spermatozoa that do not show signs of cell or DNA damage or even death of the cell, this is called apoptosis. These damaged sperm can be removed from the sample using this technique because the membranes of damaged cells contain markers that can be detected and then can obtain a fraction that is free of these dead cells, therefore, we have better quality.
The embryologists incubate the selected sperm with Annexin coated with magnetic microparticles and pass it through a column where a magnetic field has been applied. The apoptotic sperm will be retained in the column while the non-apoptotic will be passed through it without being retained, so the fraction obtained will only contain healthy spermatozoa with the best physiological quality.
When is it recommended?
- male patients of more advanced age
- male patients with a high level of DNA fragmentation in their sperm sample
- patients who have had repeated miscarriages with an undefined cause
- patients who have had at least one previous treatment cycle or who have poor embryo quality and which is not attributed to the eggs
This procedure can be used with conventional IVF or ICSI. This non-apoptotic sperm fraction increases the fertilization capacity of the sperm and allows it to achieve a higher gestation rate by approximately 10- 15%.
Time-lapse
It’s a pioneering technique that maintains the culture conditions intact and reduces the handling of the embryo. It allows embryo cell division to be recorded and viewed on a monitor in real-time. We can watch the cell division of the embryos anytime without manipulation. When traditional incubators were used, the embryos had to be removed at certain hours from the incubator to check them and their development under the microscope, although these intervals were very short, the environmental conditions were altered during that time.
Time-lapse incubators offer the possibility to view the morphological characteristics without the need to remove the embryos from the incubator so that environmental stress experienced by the embryo is reduced. The conventional way of monitoring and the evolution of the embryos is to extract the embryos from the conventional incubator every day and morphological parameters will be evaluated under the microscope. Among them, we see the number of cells, the symmetry of the cells, and the fragments of the embryo. With this information a quality rank is assigned to each embryo, in this way, it allows the selection of the best quality embryo for transfer.
Time-lapse technology provides highly accurate information throughout embryologic development, allowing us to select a group of embryos that have the greatest potential to implant and lead to a pregnancy. In addition, it allows us to explain those cases in which good-quality embryos do not implant. This type of incubator can be used for all assisted reproduction patients. It is recommended for all treatments including IVF, egg donation, and embryo donation but especially for those who have a higher number of embryos. When there are more than 2 embryos, the selection of those with the best quality and the highest potential to achieve pregnancy is done more precisely. Thanks to time-lapse, there is between 10-20% higher probability of implantation than using conventional culture and selection techniques.
Pre-implantation genetic testing for aneuploidies (PGT-A)
It’s a genetic test performed on embryos produced through IVF, and it has to be done with ICSI fertilization. PGT-A detects abnormalities in the number of chromosomes in the embryos, also known as aneuploidies. Chromosomes are very important for healthy growth and development. The embryos with the incorrect number of these chromosomes typically do not result in a successful pregnancy or may lead to a birth with a genetic condition, for example, Down syndrome, Turner syndrome, etc. The embryos with the correct number of chromosomes have a better chance of give a successful pregnancy. PGT-A identifies those embryos with the correct number of chromosomes, so the embryologists can select the best embryo with the best chance of leading to IVF success.
When is it recommended?
- women that are over the age of 35
- women after 2 or more failed IVF cycles
- women who suffered 2 or more miscarriages due to unknown causes
- women who went through a pregnancy that involved chromosomal abnormalities
- couples in which men’s sperms reveal errors during meiosis
How does it work? First, the ICSI procedure is done, and then the next day the embryologists will see how many embryos they have and then they will see the embryonic development. There can be an embryonic development until day 3 or 5, if there are a lot of embryos, it’s better to take them to day 5. If there are not so many of them, it’s better to do it on day 3. When the biopsy is done, a few cells are carefully removed from the part of the embryo that will form the placenta and is taken for biopsy. The samples are sent to a genetic laboratory while the embryos remain safe in the culture, or in some cases, they can be frozen. In the genetic laboratory, they have all the techniques to analyse the genetic material present in each embryo, and they will check which embryos don’t have any abnormalities. These are the ones that are going to be transferred because they’re most likely to result in success. If there are more than 1 or 2 embryos without aneuploidies, they can be frozen for future use.
What are the advantages of PGT-A?
- increases the implantation rate of embryos and consequently, higher chances of pregnancy
- lowers the risk of miscarriage
- increases chances of having a healthy baby
- lowers the probability of going through various cycles
