In 1983, the first baby was born using Frozen and then thawed human embryos. Since then, freezing embryos is an integral part of IVF and Assistive Reproductive Technologies (ART). This technique has undergone a lot of advancements and now it is considered a safe technique for the long-term life of the child born out of Frozen Embryos.
Why and When should you Freeze your embryos?
Embryo Freezing is a boon for PCOS patients. Deferring the transfer of embryos to the next menstrual cycle not only increases your chances of IVF success but also minimizes the chances of OHSS (Ovarian Hyper Stimulation Syndrome).
For a second child: Even if you are planning for a fresh transfer, the extra embryos of good quality (Grade A) can be frozen. They can be used later if you are planning for another baby or in case of IVF failure.
Fertility Preservation: If you want to defer having a baby for a few years because of a career or any other reason, you should get your embryos or eggs frozen. When you are young and less than 30 years, your eggs are generally of good quality and quantity. As egg increases, freezing the embryos or eggs at a younger age minimizes the age-related complications of pregnancy. Also, the chances of losing all good eggs because of increased age are not there.
Stages of the Embryo that can be frozen:
Embryos can be frozen at different stages of their development:
- Day 1 (Pronuclear Stage) when they are just a single cell.
- Day 2 or 3 at Two to Eight-cell Stage.
- Day 5 or 6 in their development i.e. the Blastocyst Stage.
Though embryos can be frozen at any stage of development, the majority of embryos are stored either at Day 2/Day 3 stage or at Blastocyst stage.
In theory, there is no upper limit for embryos to remain frozen once they have undergone Cryo Preservation using Cryo Vitrification. They are stored in special containers (Cryocans) in Liquid Nitrogen where the temperature is -200 Deg C. The usual storage period of embryos is normally 10 years.
In 2020, the news made headlines after a baby was born from an embryo that was frozen 27 years ago!
Are Frozen embryos better than fresh embryos?
It depends on multiple factors like the age of the patient, the stimulation process, the ovulatory status and pre-existing PCOS amongst other factors.
As per a study published in the Fertility and Sterility journal in 2018, Frozen embryo cycles have higher Live Birth Rates esp in PCOS patients (high responders) than fresh transfers. Also, SART (Society for Assisted Reproductive Technologies) found that Live Birth Rates were significantly higher than fresh transfers in women of all age groups.
At Gunjan IVF World, we have also witnessed significantly better IVF results with frozen embryos. Hence, we recommend our patients to opt for frozen embryo transfers esp in previous IVF failures.
When can frozen embryos be transferred?
You can get your frozen embryos transferred in any menstrual cycle at your convenience. Generally, the process of embryo transfer starts from Day 2 of your menstrual cycle when Estradiol tablets or gel are started to develop the Endometrial Lining of the uterus. Usually, the endometrial lining takes about 15-20 days to develop. The lining is continuously monitored by periodic ultrasound scans. The lining should ideally be 8 to 10 mm with a triple-layered appearance for an ideal transfer.
Once the desired parameters are met, we start Progesterone hormone supplements to mimic the Luteal phase. In the meantime, the frozen embryos are thawed (de-freeze) and then transferred. The transfer is done after 3 to 5 days of starting Progesterone depending on whether it is a Day 3 embryo or Blastocyst.
At Gunjan IVF World, we can keep embryos stored for unlimited time as per your wishes with an annual renewal process.
Can Day 3 embryos or Blastocysts be frozen?
Only excellent quality (i.e. Grade A) embryos are considered for freezing. Day 3 embryos should be preferably frozen at 6 to 8 cell stage. Blastocyst embryos can be frozen as well with good recovery rates. If you are planning for PGD/PGS, your Blastocysts are frozen after taking a small sample of the embryos. The sample is then sent for genetic testing.
Percentage of the frozen embryo that can survive during the thawing period
Due to the latest vitrification techniques, 80 to 90% of embryos survive the thawing process and are considered suitable for transfer.
It is beneficial for:
The frozen embryo may be a good option for certain people like:
- The ones who are suffering from genetic disorders that affect reproduction.
- The one who will soon undergo chemotherapy.
- The one who depends on medicines to increase fertility.
- The couples who are of the same gender and want to become parents.
- The ones who are LGBTQ (lesbian, gay, bisexual, transgender, and queer or questioning).
Are Babies born from Frozen embryos healthy?
Yes, the babies born are healthy. You can read in detail in our other blog ‘Are Babies born from Frozen embryos healthy?
How can I be sure that only my embryos will be transferred (and no Mismatch)
At Gunjan IVF World, we have a well-defined process of labelling, freezing and accurately identifying your embryos. These labels are indelible and cannot be manipulated. Before thawing, the embryos are checked by at least 2 designated persons so that no error should ever occur. Multiple tier system of record-keeping is maintained.
Precautions you should take after the Frozen Embryo Transfer (FET)
- Take your medicines as prescribed. Do not skip any dose after the embryo transfer.
- You can continue to maintain your normal day to day activities like easy walking, household chores and light yoga. The strenuous activity of all kinds should be avoided.
- Avoid Stress. Watch comedy shows or do anything that makes you happy.
- Bed rest is not required.
The approach of frozen embryo transfer increases the chances of having a baby compared with fresh embryo transfer. Thus, a frozen embryo proves to be more effective and safe. It leads to a successful pregnancy and delivery.
Frozen embryos offer flexibility in choosing the right time for IVF treatment. You Save Time, Money and also physical and emotional stress involved in doing the entire IVF cycle afresh.