New tech offers 24/7 monitoring for high-risk pregnancies

By Stephen Beech

A new wearable "baby bump" monitor can provide round-the-clock care in high-risk pregnancies.

The soft, ultrasound patch continuously monitors the unborn baby for hours at a time, say scientists.

And it does so consistently — even as the fetus and umbilical cord constantly move during pregnancy, according to a study published in the journal Nature Biotechnology.

The device, which can spot early warning signs of potentially deadly pregnancy complications such as preeclampsia, was made by engineers at the University of California San Diego.

They say the technology could help doctors detect complications earlier in high-risk pregnancies.

In one case during clinical testing, the patch detected prolonged abnormal fetal signals that prompted medical intervention through an early cesarean delivery, which researchers say may have helped save the baby's life.

The research team say the new technology could also expand access to prenatal care in low-resource settings, where skilled ultrasound technicians and continuous, long-term monitoring is often limited or unavailable.

Study co-first author Geonho Park, a chemical and nano engineering Ph.D. student at UC San Diego Jacobs School of Engineering, said: "Wearable ultrasound technology has the potential to enable continuous prenatal monitoring and improve pregnancy outcomes in ways that were previously not possible."

He explained that most current prenatal ultrasounds usually provide only brief snapshots of fetal health and require trained sonographers to operate the equipment.

But the new wearable ultrasound patch is designed to stay on the body and continuously track a baby's anatomy and blood flow in real time, without requiring someone to manually guide the ultrasound probe.

Study co-author Yizhou Bian said: "To comprehensively monitor mothers and babies over the amount of time needed to catch complications like preeclampsia, you need a system that can work continuously and largely on its own.

"That is why the sensing depth, functional capabilities and autonomy of this ultrasound technology are critical."

The researchers explained that a major challenge in continuous fetal monitoring is that both the fetus and the umbilical cord are constantly moving.

To address that issue, the team developed autonomous tracking algorithms that automatically identify and follow the umbilical cord as it moves.

That enables the device to maintain consistent measurements even while the mother or fetus changes position.

Study co-author Hao Huang said: "With continuous monitoring, we were able to observe dynamic fluctuations in blood flow that would likely be missed with conventional ultrasound exams."

Park added: "Our system even detected an abnormality during one of our clinical visits.

"That pregnancy later resulted in a delivery at 29 weeks, and it demonstrated how continuous monitoring could help identify complications much earlier than we can today."

This project builds on over a decade of research at UC San Diego in the lab of chemical and nano engineering professor Sheng Xu.

His team has led development of wearable ultrasound technology for a range of healthcare applications, including non-invasive monitoring of central blood pressure as well as mobile heart monitoring and efforts to use everyday gestures to reliably control robotic devices.

For the latest work, researchers evaluated the wearable ultrasound patch through a multi-center clinical study conducted at Jacobs Medical Center at UC San Diego Health and the John Radcliffe Hospital at the University of Oxford.

In tests, the patch produced measurements that closely matched those from standard handheld ultrasound devices.

The research team also collected continuous monitoring data for hours at a time across 62 pregnancies, including healthy pregnancies as well as pregnancies complicated by gestational diabetes, preeclampsia, high blood pressure and abnormal fetal growth.

The research team now plans to integrate the patch into a compact electronic system that could eventually allow it to operate wirelessly.