Benefits of Frozen Embryo Transfer Technique

Synopsis

Frozen Embryo

Childlessness was considered a social stigma since ages. Millions of couple could see their dream come true with the introduction of in vitro fertilization in 1978 due to the commendable work of Patrick Steptoe and Edwards. Louis Brown was the first IVF baby born in 1978 and her birth paved the way for a revolution in the
field of reproductive medicine and infertility.

IVF involves fertilising an ovum and sperm outside the body in a laboratory , and transferring the formed embryo back into the uterus. The process of placing the embryo in the uterus is called embryo transfer. The embryo transfer can be done fresh ,that means in the same cycle of stimulating the ovaries or frozen that
means in the subsequent cycle after preparing the endometrial lining.

History:

Zoe Leyland is the world’s first baby delivered from a frozen embryo transfer in 1984 in Australia. The embryo was frozen for two months, before being implanted in the woman’s uterus, where it developed normally. The technique of
embryo freezing opened a horizon of possibilities in the field of ART(Assisted reproduction techniques).

Benefits of the Technique:

Before the advent of embryo freezing , surplus embryos had to be discarded after fresh embryo transfer. With improving technology and laboratory conditions, the embryologist became well versed with the technique of embryo freezing , extra embryos could be frozen for further use .

If the first attempt resulted in a failure, the frozen embryos can be thawed and used for transfer in subsequent cycles.

Also it could be used for future pregnancies in a couple who has conceived in earlier attempts and their extra embryos are freezed with the respective ivf centre.

It also conferred advantage in cases where the uterus is not very receptive due to thin endometrium,and waiting for the right endometrium before transfer became possible. The risk of delayed onset ovarian hyperstimulation in PCOS patients was considerably reduced due to frozen embryo transfers. It became possible for genetic testing of embryos and transfer of a genetically normal embryo in case of parents who had some genetic disorder which could be transmitted to next generations.

The longest known duration for which the frozen embryo resulted in a live birth is 22 years.

Techniques of embryo freezing:

There are two methods of embryo freezing.

1. Slow freezing

2. Vitrification

Vitrification has become the mainstay of the embryo freezing technique as there is less damage to DNA as the formation of ice crystals in the intracellular and extracellular space is less leading to increased survival rate
of embryos after thawing compared to the technique of slow freezing.

Studies have also shown that the success rate of IVF is considerably higher in frozen embryo transer. Also there were lesser chances of low birth weight and preterm babies after frozen transfers. But inspite of this, more clinical trials are needed before using frozen embryo transfers in all the patients as
a standard norm.

To summarize, frozen embryo transfer if used wisely and selectively will definitely help in achieving better ivf success rates.