Engineers at the University of California, San Diego, have developed a soft, wearable ultrasound patch that can continuously monitor a fetus for hours at a time while maintaining reliable performance even as the fetus and umbilical cord move throughout pregnancy.

The device could help physicians identify complications earlier in high-risk pregnancies. During clinical testing, the patch detected prolonged abnormal fetal signals in one case, prompting an early Cesarean delivery. Researchers said the intervention may have helped save the baby’s life. The technology could also improve access to prenatal care in low-resource regions where trained ultrasound specialists and continuous monitoring are often unavailable.

“Wearable ultrasound technology has the potential to enable continuous prenatal monitoring and improve pregnancy outcomes in ways that were previously not possible,” said study co-first author Geonho (Tom) Park, a chemical and nanoengineering PhD student at the UC San Diego Jacobs School of Engineering. Park co-led the study with fellow UC San Diego Jacobs School of Engineering co-first authors Yizhou Bian, Hao Huang, and Sai Zhou.

Autonomous Tracking Overcomes Fetal Movement Challenges
Most prenatal ultrasounds provide only a brief look at fetal health and require trained sonographers to operate the equipment. In contrast, the new patch is designed to remain on the body and continuously monitor a baby’s anatomy and blood flow in real time without the need to manually position an ultrasound probe.

“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,” Bian said. “That is why the sensing depth, functional capabilities, and autonomy of this ultrasound technology are critical.”