It has been over 30 years since Lindsey and Tim Pierce's baby was conceived. But it wasn't until this July when Thaddeus was born. The embryo that is now over a month old is actually the child of Linda Archerd and is one of the four resulting from the in vitro fertilization procedures that this American woman underwent in 1994.
Yes, this embryo has broken current records and was successfully thawed three decades after its conception in a laboratory. This was possible thanks to Linda's determination to ensure that the three embryos she couldn't gestate had a happy ending. Linda managed to give birth to one of them. Today, her daughter has given her a grandson who is 10 years old. However, she never got to carry any of the others as her marriage ended sooner than expected.
The entire process took place at the Rejoice Fertility Clinic. John Gordon, the director, explains to this newspaper that this is the second time they have carried out this type of treatment. "In 2022, we already did it with embryos frozen since 1992. Ridgeway became parents of twins," he points out. Gordon emphasizes the value of adoption. "There are thousands waiting to be 'welcomed,' and this is an example that it can be carried out without fear."
Here, the embryo adoption program through Open Heart is key. Gordon highlights the desire of both couples, Pierce and Ridgeway, to be adoptive parents. "We believe so much in adoption that we want the embryos that no one else has adopted, not because we want to be famous or break a record, but because our faith drives us to give these embryos that no one else has wanted to adopt the opportunity to be part of our family." And so they did, although not without subjecting them to genetic testing to rule out anomalies.
Gordon also highlights the challenges that the Head Embryologist, Sarah Atkinson, faced in carrying out the process. "The thawing process was more laborious and very different from how it is done today [three decades have passed]. When Atkinson showed me how they were frozen back then and how she carried it out, I was amazed by the techniques that we now consider almost homemade," details Gordon.
Regarding the long-term cryopreservation of the embryo, Antonio Requena, chief medical officer at the Valencian Institute of Infertility (IVI RMA), states that "it reinforces the idea that, if a couple no longer wishes to use their embryos and meets the requirements to donate them, they are providing an option to other infertile couples, like they were at some point, to have a child or start a family."
What happens to embryos that are not implanted?
In our country, as in others, there are three legally contemplated scenarios to cover situations where a couple no longer intends to gestate the embryos conceived in the laboratory, either because they have already created the desired family or for other reasons. Donating them to other couples, for research, and destroying them. Requena explains each one. In the first case, as in Linda's situation, "certain requirements must be met, the same as those applied to gamete donors, according to the Spanish Assisted Reproduction Law."
Tim and Linsey Pierce, the couple who adopted the over 30-year-old embryo.Courtesy of Rejoice Fertility Clinic
If they decide to donate them for research, "this option is highly regulated," assures Requena. "Any study involving embryos needs to go through a series of approvals before being carried out. In this case, the couples who donated for research are always informed about the project in which their embryos will be used, as they must be aware of it." A recent example is the achievement of the Institute of Bioengineering of Catalonia (IBEC): recording for the first time how a human embryo implants in real-time. Samuel Ojosnegros, the team's leader, explains that "thanks to the generosity of the informed families, this breakthrough was possible."
The third option is the one Linda never wanted, especially when she reached menopause, hence her determination to find adoptive parents for her children. Linda used to pay over a thousand dollars a year to preserve her "little ones." In our country, as Requena comments, there are established protocols. "The requirement is that the woman has a report from two independent gynecologists stating that the patient is no longer fit to use those embryos. Only in that case does the law allow for their destruction."
The details of this science fiction-like story of the baby have been published in MIT Technology Review and "highlight the cryobiology as a fundamental tool within assisted reproduction techniques," emphasizes Luis Quintero, medical director at Next Fertility. And no, there is no time limit. "In our country, there is no maximum time," Requena confirms.
Cryopreservation techniques without time limit
"We know that as embryo cryopreservation techniques have improved, the survival rate is increasingly higher," adds the IVI RMA spokesperson. And their viability, regardless of how long they have been frozen, "is ensured as long as the appropriate conditions are maintained," specifies Quintero.
Quintero recalls that 44 years ago marked a milestone that would change assisted reproduction. In 1983, the prestigious scientific journal Nature published "the first human pregnancy after the transfer of a thawed embryo, radically changing assisted reproduction techniques, offering solutions to multiple problems faced by many couples with fertility issues."
The embryos that were implanted in Linsey Pierce.Courtesy of Rejoice Fertility Clinic
This advancement marked a turning point. "It not only allowed the safe freezing of embryos but also the preservation of eggs and sperm, which is of great importance to preserve fertility in men and women who wish to postpone parenthood, which would otherwise be impossible, forcing them to reproduce at certain vital moments that may not be the most convenient," argues the director of Next Fertility.
How does embryo cryopreservation work?
Experts explain that human embryos are kept frozen in liquid nitrogen at a constant temperature of -196º Celsius, "this being the ideal method for their maintenance given their particular characteristics, especially that it does not require an external power source that could fail due to uncontrollable factors, as is the case with other energy-dependent freezing methods like electric or similar," Quintero explains.
Once the embryo is conceived, its life is paused until the moment it moves to a uterus, and the survival rate throughout this process is over 95%, with failures occurring during thawing. "This ensures stable conditions without variations. In theory, it maintains the same conditions from day one until they are thawed, regardless of the time that has passed," Quintero adds.
Embryos "do not suffer while they are cryopreserved," details Requena. The risk lies in the previous and subsequent stages. "It is the processes of freezing and thawing that could potentially cause damage to the embryo." Their morphology can also be evaluated. In this case, "the embryologist assesses the characteristics that are used to classify it. If there are significant alterations, it is considered that it has not survived," explains the spokesperson for IVI RMA.
To determine if the embryo has suffered any damage, Requena explains in detail how they observe embryonic survival. "That is, the embryo is thawed, and depending on the moment it was frozen, it is left for a period to observe if it continues to evolve correctly. If so, we consider it a viable embryo."
The freezing of embryos has enabled the development of other processes that would be impossible without their involvement, such as all techniques of embryonic genetic diagnosis, which help couples and/or women fulfill their dream and should be their clear objective: "To have a healthy baby," concludes Quintero.