Debunking Myths About Embryo Freezing

There are various reasons why the reproductive medicine specialist decides for embryo freezing during the IVF treatment.

It has been more than 40 years since the first successful IVF birth. It is estimated that worldwide there are more than 5 million embryos on ice. Advancements in the field of IVF are progressing at a rapid phase. Recent developments in the field of tissue freezing have enabled embryos to be frozen safely without compromising on the quality. The discussion about Embryo freezing invariably comes up in the due process of counselling infertile couples in fertility centres. There are various reasons why the reproductive medicine specialist decides for embryo freezing during the IVF treatment. In addition, the idea of marriage relationships today has also been transformed by progressive generation. Many couples these days are seen delaying their childbearing considering many responsibilities come along with having children which in turn might become a hindrance to their career . Owing to the same, many couples are in fact seen freezing their embryos(Social freezing ) .

Women should be given the freedom to make choices regarding their timing of marriage and childbirth. Egg/ Embryo freezing comes as a relief for such women. However, more importantly, they should be aware of all the available options including pros and cons of each.

Embryo Freezing:

It is a process where in the embryos obtained during IVF procedure are stored at sub-zero temperatures (as low as -196 degrees centigrade) in liquid nitrogen containers called cryotanks. Scientific terminology for this process is known as “Embryo Vitrification”. The embryos can be stored at this low temperature in the labs for many years without altering the property of the cell. At a later date, these frozen embryos can be thawed to the room temperature and transferred into the woman’s uterus so as to achieve pregnancy.

Every woman who undergoes IVF need not freeze her embryos, rather it depends on each case. Embryo freezing is recommended by a fertility specialist based on the following indications.

Indications of freezing embryos:

· Women with polycystic ovarian syndrome (PCOS). These women tend to hyper stimulate with the drugs used during IVF and are at a high risk of developing a complication called OHSS (ovarian hyper stimulation syndrome). Hence all embryos are frozen and transferred a month or two later when the hormones in the body normalise to physiological levels

· Women aged between 35-40 who have had repeated miscarriages or previous IVF failures in whom a genetic testing on the embryo is warranted to rule out chromosomal abnormality. Results of the genetic test takes few weeks and hence the embryos are frozen in the interim period.

· Women whose uterine lining is suboptimal (Thin /too thick )

· Fertility preservation for cancer patients. Drugs used for treating cancer often destroys the ovaries and reduces egg number/quality. Such woman can undergo IVF, get the embryos frozen and then safely go ahead with the cancer treatment.

· Social embryo freezing – women who are not ready to have children as of yet but are quite concerned about their declining egg quality and number.

Myths and facts about embryo freezing:

Myth: Embryos cannot be frozen for a long time.

Fact: Embryos can be frozen for many years without compromising the quality. But as a general norm usually in fertility clinics they are frozen for about 8-10 years because with each adding year, there will be a financial burden added to the couple. However, depending on each scenario, the duration can be extended. Molly Gibson – a baby girl born in 2020 in Tennessee from a 27 year old frozen embryo broke the record for the longest frozen embryo to result in a live birth.

Myth: Embryo freezing and thawing lowers the quality of the embryo.

Fact: During the process of freezing the embryos, the temperature is lowered to -196 degree Celsius. Unfortunately there is a chance of losing 1 or 2 cells in the embryo due to cold shock. However, as a thumb rule if the embryo is of top quality at the initiation of the freezing, then there is a very high chance of these embryos sustaining the process of freeze-thaw cycle. On the other hand, if the embryos are of an intermediate quality, they may not tolerate the freeze-thaw cycle well and hence there is a potential chance that we may lose those embryos during this process. Overall, the survival rate of embryos with modern techniques of freezing is around 95-98 %.

Myth: Frozen embryo transfer is not safe.

Fact: Frozen embryo transfer is a safe and effective procedure. The success and pregnancy rates between a fresh and a frozen embryo transfer are almost comparable. So one need not worry.

Myth: Babies born out of frozen embryos may develop complications.

Fact: There is no reason to believe that babies born of frozen embryos are any different from babies born naturally. However, statistics shows that babies born out of frozen embryos tend to be larger (Big babies) in comparison to babies born naturally. Scientists claim that there might be a potential role of cryprotectants (chemical solution used during freezing process which protects cells from any damage due to extreme change in temperatures) on the embryo because of which there is some amount of genetic re-programming that occurs during the baby’s development inside the womb leading on to macrosomic babies. Research is still underway in unravelling the mystery behind this

Myth: Undergoing a frozen embryo transfer will impact the long term health of the mother.

Fact: Women who undergo frozen embryo transfer have a higher incidence of pregnancy related hypertension and bleeding when compared to the others. However, by periodic and vigilant monitoring during the antenatal period these risk factors can be addressed.

Myth: There is transmission of Covid-19 across embryos in the IVF lab.

Fact: Amidst this Covid pandemic a lot of couples who freeze their embryos are quite apprehensive about transmission of Covid – 19 infection across the embryos through the liquid nitrogen containers. As a matter of fact, all fertility centres follow strict Covid protocols and the embryos are placed in high security straws and are isolated from one another. Hence, the chances of Covid 19 virus getting transmitted across the embryos through the liquid nitrogen is very negligible.

Frozen embryos –“ICE BABIES “:

From a doctor’s perspective an embryo is perhaps just a bunch of cells. In fact, it is a beautiful amalgamation of the couple’s genetic material that is so microscopic to begin with and has the potential to magically transform into a human being. For the couple, this unconditionally evokes an intricate sense of emotional bonding with the embryos the moment they are formed. They’re tiny, smaller than a speck of sand and yet stir big emotions. Research shows that figuring out what to do with surplus embryos after the family is complete is a huge ethical dilemma. While around one third of the couple willingly donate their embryos for research, the others do an altruistic embryo donation to childless couple. There are of course couple who do not choose to do the former or the latter and are left with the option of discarding their embryos due to financial constraints. But is it as simple as it sounds? To discard excess embryos? Medically we know what an embryo is. But what kind of moral and legal status does it have? Are they persons? Property? Or something in between? The debate goes on…