What’s better – using frozen or fresh donor eggs? Is there any difference in success rates? Are different protocols used? Is the quality of frozen oocytes lower than the quality of fresh ones? What are the indications for a frozen embryo transfer? These are some of the questions that many fertility patients ask before their IVF treatment. Would you like to know the answers?
Watch the video recording of a webinar by EggDonationFriends and fertility experts from Assisting Nature to find out the answers to the above questions from experts in the fertility field:
The world of medically assisted reproduction is constantly moving forwards which, at times, can leave patients feeling overwhelmed as to what is the best path forward for them. Advances in medical and scientific technology have greatly changed the way couples conceive, while new processes of freezing oocytes (eggs) and embryos have opened the door for a new generation of IVF.
In this webinar, Assisting Nature co-founders Dr. Papanikolaou MD Ph.D. and Dr. Robert Najdecki MD Ph.D., discuss the use of IVF with fresh and frozen donor eggs. Their Lab Director, Evi Timotheou MSc, explains the practices behind vitrification and looks at whether the use of frozen eggs and embryos can lead to a successful pregnancy. Assisting Nature is a clinic and college of reproduction based in Greece.
When entering the world of assisted conception, many options are presented – especially concerning oocytes. There is the question of donor gamete use and whether the use of frozen eggs might be more beneficial. How, then, can patients understand what the differences are and which choice might offer the best outcome for their situation?
As with all fertility treatments, it is hugely important to remember that not all cases are the same. Therefore, protocols and procedures are different for every patient. Medical experts now have the capacity to freeze eggs, sperm, and embryos.
Every situation is unique and so is every oocyte. Not all eggs will be fertilised, and the route from oocyte to live birth is not always easy or, indeed, guaranteed.
Dr. Papanikolaou explains how historically, a fresh synchronised cycle was the go-to IVF technique; fresh embryos, created from fresh eggs and sperm would be transferred. However, with these fresh cycles, factors such as uterine cysts or bleeding can have a negative impact on implantation. He advises that the ability to freeze gametes offers a more personal approach to assisted reproduction – individually designed protocols can be developed for each patient, allowing for treatment of any conditions which might arise during an IVF cycle. This approach results in unparalleled flexibility, which can be especially useful when seeking treatment abroad.
While gamete and embryo freezing did take place in the past, Dr Timotheou explains, the slow procedure used back then had a low survival rate, leading to a poorer quality of thawed eggs and embryos, caused by the formation of ice on the embryos and oocytes. Ice crystals can be razor sharp and easily damage the cells. Additionally, water in the cells expands as it turns into ice, increasing the risk of a rupture. In order to successfully cryopreserve an oocyte or embryo, biological matter is – in simple terms – cooled to extreme temperature. How, then, is it possible to achieve cryopreservation without forming ice?
Evi Timotheou explains that the development of new vitrification processes has significantly improved previous freezing methods and higher survival rates have been noted as a result. Vitrification is described as the transformation of a substance into a glass-like state, meaning the eggs, embryos, and surrounding solution are directly solidified to a vitreous state. In order to achieve vitrification and ensure ice crystals do not form, cryoprotectants are used; these are substances used to protect biological tissue from damage caused by freezing. The job of the cryoprotectant is to draw the water out of the permeable cells, and then replace it with itself – thus enabling protection from ice damage. The reverse then happens during the thawing process.
Vitrification has led to a revolution in oocyte and embryo cryopreservation. The Assisting Nature clinic noted an increase in survival rates of frozen oocytes and blastocysts as a result of the technique’s adoption. According to their recorded data, out of 580 cycles performed between the years 2013-2016, there was a 91% survival rate of frozen to thawed eggs from donor vitrified oocytes. This then led to a 79% fertilisation rate for their clients, with an accompanying 41% pregnancy rate. In Dr. Najdecki’s view, there is now no better or worse programs; frozen egg and embryo treatments are as viable for patients as fresh ones. Now, it’s simply a matter of choosing the right treatment for each patient.
While ongoing developments in IVF treatments have opened many doors in the world of fertility treatments, the pace of new developments can be overwhelming for patients. For this reason, the co-founders at Assisting Nature are keen to stress that clinics should not treat all cases in the same way. Every situation is unique and individual protocols need to be created in order to generate the best possible outcome – for every patient under their care.- Questions and Answers