IVF and IVF with donor eggs – the more additional procedures you have, the better success rates. Is this true? What is the expert’s opinion and medical evidence? Watch the recording from live webinar and Q&A session with Dr. Yadira Pallás Gálvez, an experienced embryologist from the Reproduction Unit of Hospital Clínica Vistahermosa (PreGen)
in Alicante, Spain.
Do additional lab techniques mean higher IVF success rates?
There is much conflicting and controversial information surrounding additional IVF procedures leaving some patients to approach these laboratory “add-ons” with caution. Questions are inevitably raised regarding the actual techniques used and whether an increase in additional treatments will actually provide an increase in pregnancy rates.
In this webinar, Dr Yadira Pallas Galvez, senior clinic embryologist at PreGen in Alicante, Spain, describes the basic IVF procedure, outlining the various additional techniques currently used and explaining when further treatment options should be recommended for patients.
The object of IVF is to fertilise eggs and create embryos outside of the body. To
optimise the number of potential embryos, the first step of IVF is to increase the
amount of natural eggs produced by the body
, this is known as ovarian stimulation. During this stage of the IVF process, the follicles (the cavity which surrounds the oocyte) are regularly checked by ultrasound to establish the optimal time for their retrieval. An egg collection is then carried out, under sedation, and once any oocytes have been obtained, they are placed in a special incubator until the sperm has been properly prepared in the laboratory.
Finally, either IVF or ICSI is performed using
the fully mature eggs.
For IVF the sperm and egg are placed together in the incubator, whereas with ICSI one specially selected spermatozoa is injected into one egg; this micro injection technique is usually used in cases of male factor infertility.
After 18-20 hours the first phase of fertilisation take place and embryo cultivation begins. As they grow, all embryos are classified by the embryology team according to their development. This grading helps embryologists determine when the transfer will take place and which embryo/s should be transferred or vitrified (frozen).
Embryo transfers are not painful and do not require sedation.
The embryos are inserted into the uterine cavity using a catheter and ultrasound guidance. The number of embryos transferred depends on the patient’s history, the embryonic quality and medical advice; clinics aim to transfer a single, good quality blastocyst (five-day embryo) to achieve the best results however, this isn’t always possible.
So, what else can patients do to try to achieve a good quality blastocyst for transfer?
Where male infertility is a factor, Dr Galvez would recommend a MACS test. All spermatozoa have a limited viability and through the process of Magnetic Activation Cell Sorting (MACS), any apoptotic (dying cells) sperm become separated. This separation of the gametes (sperm) enables embryologists to only use sperm which is alive and healthy for the fertilisation process. Apoptotic sperm are likely to include a higher amount of DNA fragmentation which can result in abnormal embryo development. DNA fragmentation cannot be detected when using basic microscopic methods. Dr Galvez suggests MACS testing for patients who are suffering from recurrent implantation failure, a low fertilisation rate or poor embryo quality, and when male age is increased.
Research into genetics has opened up huge opportunities in the field of assisted reproduction and with the introduction of preconception genetics testing, medical teams now have the possibility of increasing the chances of a genetically healthy pregnancy. Specialists would typically test for any recessive diseases, these include conditions such as Cystic Fibrosis, Spinal Muscular Atrophy and Beta Thalassemia, which occur when both parents are determined to be carriers of mutations for the same disease. Genetics testing allows medical teams to review the compatibility of couples to determine whether they are genetically suited. For couples who are incompatible further tests and options are available and the use of donor gametes may be suggested as an alternative approach.
Genetic screening can also be carried out on embryos by using PGT-A (pre-implantation genetic testing for aneuploidies).
Aneuploidy is the presence of an abnormal number of chromosomes in a cell and is the most frequent cause of implantation failure, miscarriage and congenital anomalies (birth defects). The risk is known to increase with maternal age. Pre-implantation screening can improve implantation and pregnancy rates and maximises the opportunity of transferring only euploid (chromosomally equal) embryos. The aneuploidy testing follows an embryo biopsy, where a small number of cells and removed and then analysed.
The use of time lapse technology is another additional treatment regularly offered to patients, and one which PreGen clinic has recorded a 20% pregnancy increase following their usage.
Time lapse is an optical system within the incubator which allows embryologists greater opportunity to study embryonic development throughout the entire cultivation period.
When time lapse imaging is not used by clinics, embryologists have to physically remove the embryos at least every 24 hours so that their development can be analysed. Removing the embryos from their incubator exposes them to microscopic lights, temperature and humidity changes and human manipulation. Time lapse incubators limit this exposure and instead offer constant, optimal cultivation conditions. As embryologists are afforded around the clock embryo observation, time lapse technology helps them to select only those with the highest implantation potential for transfer and freezing.
Assisted hatching and embryo glue are two other laboratory add-ons which can be performed to aid implantation. In assisted hatching a minor defect is created in the embryo membrane which potentially increases implantation potential. It would typically be recommended for embryos that have morphological issues that might make implantation more difficult. Embryo glue is used as a transfer medium and is enriched with everything an embryo needs to help it implant. As of yet, no clear data has been collated to confirm whether these two techniques have a significant impact on implantation.
Dr Galvez advises that it is important for patients to remember that these are additional treatments and are not always necessary, or applicable, for everyone. Clinics must assess all patients individually and only suggest extra lab techniques which will make a difference in each unique set of circumstances.