Let’s break down the tricky, life-changing science behind womb transplants: ScienceAlert
The ability to conceive, bear and give birth to a biologically related child is a deep desire for many women and their partners.
Since the introduction of IVF in 1978, many people in countries like Australia have had access to support and resources to help them achieve their reproductive goals.
For some women, the lack of a functioning uterus has held this opportunity out of reach. This includes people with a congenital condition such as Mayer-Rokitansky-Küster-Hauser syndrome and those who have had a hysterectomy for medical reasons.
For these women, the only parenting options were surrogacy or adoption. Access to both is often difficult.
Womb transplants change that. From next year, womb transplants will be trialled in Australia.
However, there are risks and ethical concerns that need to be addressed before it can become mainstream clinical treatment.
How does the process work?
Uterus transplantation is a set of medical procedures in which a donated uterus is surgically removed from a suitable donor and transplanted into an eligible recipient.
Hormones are used to stimulate menstruation in the recipient, and once the uterus is functioning normally, an IVF-created embryo is transferred to the woman’s uterus.
After successful implantation and healthy development, the baby is delivered by Caesarean section.
Indeed, a pregnancy with a uterus transplant is considered high risk and the woman may not feel the contractions. Women with congenital absence of a uterus will not be able to give birth vaginally.
As with all transplants, the recipient of the uterus is prescribed an immunosuppressive drug to prevent rejection of the donor organ. These drugs are given at levels deemed safe for the developing fetus.
Close monitoring continues throughout pregnancy to ensure the safety of the woman and the fetus.
Immunosuppression continues until two healthy babies are born or five years after the transplant, whichever comes first.
The uterus is then surgically removed by hysterectomy, which helps stop the immunosuppression, which carries risks and side effects.
The risks of immunosuppression include infection, low blood cell count, heart disease, and suppression of bone marrow growth. And these risks increase over time.
The uterus transplant is an “ephemeral” transplant: a non-vital temporary transplant, intended only to allow reproduction. These characteristics distinguish it medically and ethically from other transplants.
When did uterus transplants start?
Scientists began developing uterus transplantation in animals in the 1970s. The first attempts in humans were in 2000 (Saudi Arabia) and 2011 (Turkey), both of which failed.
After 14 years of research, Professor Mats Brannstrom and his team at Sweden’s Sahlgrenska University Hospital launched the world’s first human trials in 2013. In 2014, the first healthy baby was born.
With more than 25 countries currently performing or planning uterine transplants, it is estimated that at least 80 procedures have been performed, resulting in more than 40 healthy live births.
Although not all transplants are successful, the live birth rate from a properly functioning uterus after transplant is estimated to be over 80%.
In Australia, two trials have been approved and plan to start in the next 12 to 18 months.
Who makes a donation?
Until now, most uterine transplants have used altruistic living donors, usually a mother donating to her daughter or an aunt to her niece.
But cases using deceased donor wombs have also been successful, with at least four healthy live births reported.
Deceased donor uteri are primarily provided through standard methods of family consent for medical research. But in the future, they may be provided through modified organ donor registration processes to include the uterus.
Currently, only pre-menopausal women can be uterus donors, and living donors must have had a successful pregnancy in order to donate. But that may not be a requirement for deceased donors, potentially allowing for younger donors and increasing the availability of uteri for transplantation.
Of the two approved Australian trials, only one (run by the Royal Hospital for Women, for which I provide independent ethical advice) will perform uterine transplantation from living and deceased donors. The other (through the Royal Prince Alfred Hospital) will only test living donor transplantation.
Participation in these uterus transplant trials will remain limited while uterus transplant is still in the research phase, and will depend on the availability of funding.
What are the risks of living donation?
For recipients, the main surgical risks are organ rejection, infection, formation of blood clots or thrombosis, as well as risks related to the duration of the procedure (5 hours on average) such as blood clots (including in the lungs) and immunosuppression.
Although challenging, these risks have been minimized through close monitoring and early intervention using blood thinners and encouraging recipients to move soon after surgery.
For living donors, the physical risks stem from the duration of the procedure (6 to 11 hours) and the operative and postoperative complications, the most frequent being lesions and infections of the urinary tract.
There are also ethical and psychological risks. These include the possibility that a potential donor will feel pressured to donate to a family member and feel guilty and fail if the transplant is unsuccessful or leads to undesirable results.
These risks can be reduced with appropriate advice and support. But as with all altruistic organ donations, they cannot be eliminated entirely.
What about the deceased gift?
Transplantation from a deceased donor also carries risks, but involves less surgical time than transplantation from a living donor (usually 1–2 hours) and therefore requires fewer medical resources and personnel.
Transplantation from a deceased donor may be less burdensome from an ethical point of view. There is no prospect of pressure, guilt or surgical risk for the deceased donor, who must have been declared brain dead and be suitable for multiple organ donation. Their organs can only be obtained with proper consent, following standard protocols and procedures.
In Australia, as elsewhere, organ donors are rare. But deceased donors can be traced through existing donation registries and consent processes, such as those run by DonateLife and NSW Organ and Tissue Donation Services.
Why investigate both types of donations?
It is important to be able to compare the results of living and deceased donations in similar recipients and settings. This will inform future guidelines and policies regarding uterine donation and whether it can become routine clinical practice.
Emerging evidence suggests that donating from a deceased may yield better outcomes for recipients. Using organs from deceased donors allows for longer veins and arteries to be recovered, allowing better blood flow to the uterus and potentially greater success in transplants and pregnancies.
So, although there are currently fewer cases of deceased donors, there are good medical and ethical reasons for Australian research into womb transplantation with deceased and living donors.
Mianna Lotz, Associate Professor of Philosophy and Chair of the Faculty of Arts Human Research Ethics Board, Macquarie University
This article is republished from The Conversation under a Creative Commons license. Read the original article.