What does Vitrification mean in IVF?
Vitrification comes from the Latin word for glass, vitrum. In the context of fertility and IVF, vitrification is essentially the rapid freezing process so that the water molecules do not have time to form ice crystals and instead instantly solidify in a glass-like structure. This technique is much more complicated than the earlier ‘slow freezing’ procedures and has yielded good results. Over the years, the pregnancy success rates through vitrification have become equivalent to fresh IVF cycles, a remarkable achievement.
To better understand the difference between vitrification and slow freezing, imagine getting food out of your home freezer. Sometimes, do you see tiny crystals of ice on your food? That is somewhat like what scientists used to see inside the cells in the laboratory when they formed ice crystals, which fragmented, fractured, and destroyed most of the specimens, frozen slowly.
Conversely, vitrification uses an exceptionally rapid freezing rate (about 15,000 ℃/min) to achieve near-instantaneous freezing. Additionally, vitrification preserves the crystalline lattice structure, which prevents ice crystal formation. Multiple studies have found that any vitrification procedure causes minimal damage. Furthermore, vitrification technology keeps specimens indefinitely with no or little detrimental impact on sample storage duration. Vitrification brought about exceptional results.
In What Situations Is Vitrification Process Suitable?
- Women who, for one reason or another, wish to delay childbearing.
- Cancer patients, as well as others who will receive gonadotoxic therapies.
- Women who have undergone multiple ovarian surgeries, such as endometriosis.
- Individuals for whom it is desirable to perform embryo transfer in a cycle other than the one in which follicular stimulation takes place because of the risks of ovarian hyperstimulation syndrome (OHSS), the development of polyps, hydrometra, or hydrosalpinx, or inadequate spermatozoa.
- Those who do not respond well to ovarian stimulation or have adequate oocytes, especially if they are going for a pre-implantation genetic testing cycle.
What is the Process of Vitrification Step-by-Step?
The process of egg and/or embryo vitrification encompasses three key parts:
First, the eggs and/or embryos are made in high concentrations with a substance known as cryoprotectants that supports a fast dehydration of the cells.
The eggs and/or embryos are placed in small storage devices (usually straws) that will enable ultra-fast cooling to preserve and keep the egg during freezing effectively.
Third, the straws holding the sperm, eggs, or embryos are frozen as quickly as possible, in many instances at several thousand degrees per minute. Such fast freezers and cryoprotectants allow the straw to undergo vitrification, resulting in a glass-like structure instead of ice. Thus, ice formation is prevented, and cells are efficiently shielded against damage.
This process for vitrification normally yields survivals greater than 90 % because it maintains the embryos or eggs and allows easy warming and transferability.
Revival of Cryopreservation process Vitrification
Whenever people wish to use their vitrified eggs and/or embryos, the above-described vitrification process is reversed to allow warming to room temperature, followed by 37℃ and rehydration. The process warms the eggs/embryos in about 20 minutes, and then they are place d in the incubator at 37℃ in the laboratory.
Embryos can be transferred to the uterus immediately, and an egg can be injected using a single sperm three to four hours later, known as intracytoplasmic sperm injection (ICSI).
Applications of Vitrification in IVF
1. Assisted hatching
The cryoprotectants used in vitrification can also harden the zona pellucida, a glycoprotein shell that surrounds the egg and embryo.
Since the embryo must hatch out of the zona pellucida after warming and uterine implantation, a hole is cut before transferring it. This is done using an exact laser, which makes it possible to transcend the hardening of the zona characteristic of the vitrification procedure. A small hole for escape is made on the zona. This part does not hurt as it is not a living component of the embryo.
2. ICSI
It is a procedure whereby one sperm is injected straight into an egg. This technique is usually carried out on patients with poor-quality sperms or if it is anticipated that sperms will fail to fertilize eggs on their own. However, as the zona pellucida is stiffer in vitrification, all the vitrified eggs are fertilized by ICSI. The alterations in the zona do not allow sperm to penetrate through the usual way; therefore, every egg needs to be injected individually with one sperm only.
What are the Advantages of Vitrification Cryopreservation?
The following are the advantages of the cryopreservation through vitrification:
- Vitrification has significantly improved embryo and egg survival rates (survival preservation), leading to more successful embryo transfer or IVF treatment.
- Vitrification has significantly improved overall successful pregnancy rates and the safety of assisted reproduction.
- Vitrification directly leads to the extensive use of elective single embryo transfer, which results in a drastic reduction in pregnancies associated with the IVF treatment.
- Patients who have more embryos from an IVF cycle can freeze them for later use to conceive.
- If a fresh embryo transfer fails, a frozen embryo is ready, so no complete IVF cycle is needed.
- Frozen embryos do not deteriorate with time. If you freeze an embryo at 30 and use it at 35, the cell quality and structure remain intact.
What are the Challenges and Limitations – Risks & Potential Long-Term Effects of the Vitrification Process?
Even though vitrification is a more reliable freezing procedure than slow freezing, with significantly higher survival rates, remember that:
- Not every frozen embryo or egg may survive the warming process. Not every frozen egg will fertilize, and not every embryo will develop further.
- Just as fresh embryos and eggs do not always develop as anticipated, frozen embryos and eggs have the same natural boundaries.
- There has been minimal concern over the amount of cryoprotectants used in vitrification and their possible impact on frozen cells. There is always an interest in minimizing risks related to the toxicity of cryoprotectants.
However, frozen embryos have the benefit of being screened for specific genetic variations and chromosomal defects such as trisomy 21, a condition that causes Down’s syndrome, among others. The ability to de-select defective embryos offers an opportunity to increase live births even more.
Why Choose Tender Palm IVF & Fertility Center for Vitrification in IVF in Lucknow, India?
Tender Palm IVF & Fertility Center offers best vitrification services in Lucknow, India for safe and effective preservation of eggs and embryos. Our state-of-the-art laboratory uses advanced cryopreservation technology to ensure rapid freezing, preventing ice crystal formation and preserving cell quality. With high survival rates and excellent outcomes, our experienced embryologists provide personalized care for women undergoing fertility preservation, IVF cycles, or genetic testing. We ensure precision, safety, and success in every vitrification procedure.