Wearable ultrasound patch could help doctors spot danger signs in pregnancy earlier

Now, in a major advance published in Nature Biotechnology, researchers led by Professor Antoniya Georgieva at the University of Oxford and founder of Safer Birth Ltd, have provided first demonstration of the feasibility of a small, wearable patch that can monitor a baby’s blood flow throughout pregnancy. In the future, it could mean that instead of having to attend hospital for a one-off ultrasound appointment which will only give doctors a snapshot of her baby’s wellbeing, a mother might be able to wear it while she’s going about her everyday life.

Professor Georgieva leads the Oxford Labour Monitoring research team at the Nuffield Department of Women’s and Reproductive Health with a focus on innovation and novel tools for monitoring pregnancies and births. To specifically develop the Ultrasound Patch (UPatch), she teamed up with Professor Sheng Xu (a world leader in novel soft electronics development), Tom Parks (a PhD student in his lab) in their stellar team at the University of California San Diego and Stanford University.  The truly multidisciplinary study involved close collaboration across the Atlantic, built on decades of complementary expertise at both teams.

The soft UPatch went through 14 prototype iterations within the study. It sits on the mother’s abdomen and captures the baby’s anatomy and blood flow over time.  Software automatically tracks the blood vessels as the baby or mother moves, providing information about the baby’s blood flow over many hours, without the need of an expert sonographer.

The technology was first designed to be attached to the necks of adult coma patients in Intensive Care Units to monitor their blood pressure. Those patients were immobile though so researchers had to adapt and improve the patch for a moving baby inside a moving mum.

The device was tested in 62 pregnancies against standard clinical ultrasound systems and showed strong agreement with routine fetal biometry measurements commonly used in obstetric ultrasound reporting and clinical decision making. Researchers then used the patch for continuous monitoring sessions lasting between one and six hours in 52 pregnant women, including pregnancies affected by pre-eclampsia, gestational diabetes, hypertension and poor fetal growth.

The study found that the device could continuously detect important changes in fetal blood flow that may indicate placental insufficiency or developing fetal compromise. In one case involving severe pre-eclampsia, the patch identified concerning blood-flow abnormalities that prompted intensified monitoring and delivery by caesarean section four days later.

Researchers say the technology could eventually help clinicians distinguish between short-lived fluctuations and sustained signs of fetal distress. This has the potential to enable earlier intervention while reducing unnecessary admissions or appointments and repeated scanning.

Professor Antoniya Georgieva, senior author and researcher at Oxford’s Nuffield Department of Women’s & Reproductive Health, said: 'Babies in the womb still cannot be monitored reliably which is a major gap in maternity care worldwide, with huge implications. Solutions are needed urgently. The UPatch technology opens the possibility of monitoring the most important signals of fetal health over much longer periods, gain essential new knowledge of how babies’ oxygen supply and wellbeing adapt inside the womb, and ultimately helping clinicians identify problems earlier. We thank all members of the wider team for their hard work on this project, and we are particularly grateful to the wonderful pregnant volunteers who made this incredible achievement possible.'

Professor Sheng Xu, senior author and engineer, now based at Stanford University, added: 'This work shows how advances in soft electronics, ultrasound engineering and clinical science can come together to address one of the most important unmet needs in pregnancy care.'

Dr Tom Park, first author and main engineer who designed and fabricated the UPatch said: 'This technology could expand access to prenatal imaging in healthcare deserts and low-resource settings, where shortages of trained sonographers often delay care for high-risk pregnancies.'

Mariana Tome, obstetric doctor and co-author, based at the Nuffield Department of Women’s & Reproductive Health, said: 'This is the kind of technology obstetrics has been waiting for, with the potential to transform pregnancy care by helping women feel safer, more reassured and better supported throughout pregnancy, while also reducing unnecessary hospital visits, repeated scans and avoidable interventions.'

The researchers say the technology could have particular value in in detecting and monitoring complications high-risk pregnancies affected by conditions including fetal growth restriction, hypertension and pre-eclampsia, where reduced oxygen and placental dysfunction can lead to serious complications including stillbirth. Researchers say this could help women feel safer and better supported, particularly in high-risk pregnancies where concerns about fetal health can cause significant anxiety.

The work was supported by Wellcome Leap through its In Utero programme, which aims to develop scalable technologies to better understand fetal development during pregnancy.

Although the current system still uses a wired backend setup, researchers say future miniaturised electronics could allow the device to become fully wireless and more widely deployable in both hospitals and community settings.

The paper, 'Fetal monitoring for high-risk pregnancies using a wearable ultrasound patch', is published in Nature Biotechnology.