World-first twin-to-twin transfusion syndrome study offers treatment hope

Twin‑to‑twin transfusion syndrome (TTTS) can be a frightening diagnosis for families expecting identical twins. For years, the only effective treatment has been fetoscopic laser surgery – a procedure that saves many babies, but is invasive and carries risks.

Now, a world‑first study led by Professor Christoph Lees and colleagues at Imperial College London and Imperial College Healthcare NHS Trust has shown that a completely non‑invasive alternative may be possible. And Twins Trust has been part of the journey from the very beginning.

A non-invasive approach to treating Twin-to-Twin Transfusion Syndrome

The study tested high‑intensity focused ultrasound (HIFU) – a technique that uses powerful soundwaves from outside the body to heat and close the abnormal blood vessels on the placenta that cause TTTS.

Researchers used Doppler ultrasound to pinpoint the tiny vessels connecting the twins’ circulations, then applied a precisely targeted beam of energy to block them. In this early feasibility trial:

• HIFU successfully blocked blood flow in 90% of the treated vessels
• None of the women or babies experienced adverse side effects
• The procedure took around 15 minutes, with follow‑up scans over the next few weeks

Because this was a phase 1a safety study, it wasn’t designed to prove full clinical effectiveness. Some families still needed laser treatment, and sadly not all babies survived – a reminder of how serious early‑onset TTTS can be. But the results show that HIFU can be used safely, and that it has genuine potential as a future treatment option.

How Twins Trust supported the research

When the study was first being developed – around seven years ago – Twins Trust helped the research team connect with fetal medicine units who might refer eligible patients. We also supported recruitment for the parents’ PPI group, ensuring families’ voices shaped the study from the outset.

We’ve continued to share updates with our community and we’re proud to have played a part in helping this innovation reach its first‑in‑human milestone.

Helen Peck, Head of Healthcare Engagement and Research at Twins Trust, said: “We are delighted to have supported this study. Any procedure that is non‑invasive and can potentially identify TTTS earlier and improve outcomes for our families with this life‑threatening condition could be a turning point.”

One family’s experience of the HIFU trial

One of the parents who took part in the trial, Brioney Garrett from Cornwall, discovered she had advanced TTTS at just 12 weeks. Laser treatment wasn’t possible, and she faced the devastating prospect of losing one of her babies.

After being referred to Queen Charlotte’s & Chelsea Hospital, Brioney chose to join the HIFU trial. The procedure worked, and she later gave birth to her daughters, Margo and Nancy – now thriving and about to start primary school.

Her words capture what this research means: “It really means the world to me to have been part of the trial – not just for my family but for other women and babies who may be able to benefit from this in the future.”

The next clinical trial will test whether HIFU can stabilise TTTS

The research team is now planning a much larger clinical trial involving 50–100 women to understand whether HIFU can reliably stabilise or reverse TTTS. If successful, this could become a safer alternative to laser treatment – especially for very early cases where current options are limited.

This work has been made possible through long‑term collaboration between Imperial College London, Imperial College Healthcare NHS Trust, The Institute of Cancer Research, and partners across the UK and Europe. Funding came from the Medical Research Council, The Wiseman Trust, the UK Focused Ultrasound Foundation, and support from patient organisations including Twins Trust.

Why this TTTS research matters for families

TTTS affects 300–400 pregnancies every year in the UK. Families often face urgent decisions, frightening uncertainty, and invasive treatment. A safe, non‑invasive option could transform care – offering earlier intervention, fewer risks, and new hope.

We’ll continue to follow this research closely and keep our community updated as the next phase begins.