Let’s break down the delicate and life-changing science behind uterus transplants: ScienceAlert

The ability to conceive, carry 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 such as Australia have access to support and resources to help achieve their reproductive goals.

For some women, not having a functioning uterus has kept this option out of reach. This includes those 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. Both are often difficult to access.

Womb transplants change that. From next year, the uterus transplant will be trialled in Australia.

However, there are associated risks and ethical considerations that need to be addressed before it becomes a 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 a suitable recipient.

Hormones are used to stimulate menstruation in the recipient, and once the uterus begins to function normally, the embryo created through IVF is transferred into the woman’s uterus.

After successful implantation and healthy development, the baby is delivered by caesarean section.

This is because a uterus transplant pregnancy is considered high-risk and the woman may not be able to feel contractions. Women with a congenital absence of a uterus will not be able to give birth vaginally.

As with all transplants, the recipient uterus is prescribed immunosuppressive medication to prevent rejection of the donor organ. These drugs are administered at levels considered safe for the developing fetus.

Careful monitoring continues throughout pregnancy to ensure the safety of both the woman and the fetus.

Immunosuppression continues until the birth of up to two healthy babies or five years after transplant, whichever comes first.

The uterus is then surgically removed through a hysterectomy, allowing the immunosuppression – which carries risks and side effects – to be discontinued.

Risks of immunosuppression include infection, reduced blood cell counts, heart disease, and suppression of bone marrow growth. And these risks increase over time.

A uterus transplant is an “ephemeral” transplant: A temporary transplant that is not life-saving and is intended solely to enable reproduction. These characteristics make it medically and ethically different from other transplants.

When did uterus transplants begin?

Scientists began developing uterus transplants in animals in the 1970s. The first human trials were conducted in 2000 (Saudi Arabia) and 2011 (Turkey), both of which were unsuccessful.

After 14 years of research, Professor Mats Branström and his team at Sweden’s Sahlgrenska University Hospital began the world’s first human trials in 2013. In 2014, the first healthy baby was born.

With more than 25 countries now performing or planning uterus 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 uterus that functions successfully after transplant is estimated to be over 80 percent.

Two trials have been approved in Australia and are scheduled to start in the next 12-18 months.

Who donates?

Most uterus transplants to date have used altruistic living donors, usually a mother donating to her daughter or an aunt to her niece.

But cases using uteruses from deceased donors 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 made available through organ donor registration processes modified to include the uterus.

Currently, only premenopausal women can be uterus donors, and living donors must have had a successful pregnancy to be eligible to donate. But this may not be a requirement for deceased donors, potentially allowing younger donors and increasing the availability of uteri for transplant.

Of the two approved Australian trials, only one (led by the Royal Hospital for Women, for which I provide independent ethics advice) will perform uterus transplants from both living and deceased donors. The other (via Royal Prince Alfred Hospital) will try a transplant from a living donor only.

Participation in these uterus transplant trials will remain limited while the uterus transplant is still in the research phase and will depend on the availability of funding.

What are the risks of live donation?

For recipients, the main surgical risks are organ rejection, infection, and blood clots or thrombosis, as well as risks arising from the duration of surgery (average 5 hours), such as blood clots (including in the lung) and from immunosuppression.

Although challenging, these risks are minimized by careful monitoring and early intervention using blood thinners and encouraging recipients to ambulate soon after surgery.

For living donors, the physical risks stem from the length of surgery (6-11 hours) and operative and post-operative complications, the most common being urinary tract injury and infection.

There are also ethical and psychological risks. These include the possibility that a potential donor may feel pressured to donate to a family member and experience guilt and failure if the transplant is not successful or results in adverse outcomes.

These risks can be reduced with appropriate counseling and support. But as with all altruistic organ donation, they cannot be completely eliminated.

How about a donation from a deceased person?

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 less demand on medical resources and personnel.

Transplantation from a deceased donor may be less ethically fraught. There is no prospect of pressure, guilt or surgical risk for the deceased donor, who must have been declared brain dead and suitable for multiple organ donation. Their organs can only be procured with proper consent, following the usual protocols and procedures.

In Australia, as elsewhere, there is a shortage of organ donors. But deceased donors can be found through existing donation registries and consent processes, such as those run by DonateLife and NSW Organ and Tissue Donation Services.

Why study both types of donations?

It is important to be able to compare living and deceased donation outcomes in similar recipients and contexts. This will inform future guidelines and policies regarding uterine donation and determine whether it can become mainstream clinical practice.

Emerging evidence suggests that deceased donation may lead to better outcomes for recipients. Using organs from deceased donors allows longer veins and arteries to be harvested, allowing for better blood flow to the uterus and potentially greater success in transplants and pregnancies.

So, although there are fewer cases of deceased donors at present, there are sound medical and ethical reasons for investigating uterus transplantation in Australia with both deceased and living donors.

Mianna Lotz, Associate Professor of Philosophy and Chair of the Human Research Ethics Committee, Faculty of Arts, Macquarie University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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