Molly Everette Gibson, an American girl, was born in 2020 from an embryo that had been frozen for 27 years. The girl, who was born completely healthy, holds the record for the longest time a human embryo has remained frozen before being born, according to various investigations.
The little girl was born from a frozen embryo in 1992 that was stored in a cryogenic freezer, as reported by The Washington Post. In 2012, the embryo was sent to the National Embryo Donation Center, a non-profit organization located in Tennessee, United States. In February 2020, the embryo was implanted in the uterus of Tina Gibson (her mother) who was only one year old when the embryo froze.
It is not surprising, therefore, that scientists ask the following question: How long can human embryos remain frozen? According to Barry Behr, a professor of obstetrics and gynecology at Stanford University, these can remain frozen indefinitely as long as they are preserved in optimal conditions.
Cryopreservation process
Through a process called cryopreservation, embryos (a collection of cells found in the earliest stage of human development) are frozen and stored in liquid nitrogen at minus 19 degrees Celsius. This activity stops all biological activity, as the teacher argues. Therefore, when you stop this activity, it pauses until you resume it again.
Even if the activity of an embryo is paralyzed for decades, once it is thawed and implanted it will continue to grow naturally. However, although there is no limit on how long an embryo can be frozen biologically, there are external factors that could damage it. For example radiation can penetrate through any material, even stainless steel thermos where frozen embryos are kept.
On the other hand, freezing methods have come a long way since embryos were frozen in the 1980s. Currently, embryos are frozen with a very fast technique called vitrification. Also, they freeze at a later stage of development, when they have about a hundred cells and are more resistant.
Despite everything, embryos are not usually stored indefinitely as patients reuse them. Additionally, parents can choose to donate their embryos, thaw them, or discard them if they don’t plan to have more children.
