Stick-On Patch Monitors Baby's Movements In Utero

Reduced or altered fetal movement is one of the most common reasons expectant parents seek urgent medical care, yet monitoring outside the hospital remains limited. Most pregnant individuals rely on self-counting movements at home, a method that can be subjective and often causes stress or uncertainty. The lack of continuous, objective monitoring makes it harder to detect early warning signs between clinical visits. Researchers have now shown that a soft, wearable patch can accurately detect fetal movements through the abdomen, enabling continuous, noninvasive monitoring from home.

The system, developed by researchers at Monash University (Melbourne, VC, Australia), consists of a thin, lightweight wearable patch measuring approximately 10–14 cm² that adheres to the abdomen like a Band-Aid. Made from soft, flexible materials, the patch is designed for long-term comfort and everyday use without disrupting normal activities.

The device uses two integrated sensors to capture subtle strain patterns on the abdominal surface created by fetal movements such as kicking, rolling, and stretching. These signals are processed using machine-learning algorithms that distinguish fetal movements from maternal motion. By combining soft sensor design with intelligent signal processing, the system can continuously and automatically detect fetal activity without requiring user input.

The technology was evaluated in a clinical study involving 59 pregnant women at Monash Health. Two patches were placed on the abdomen, and ultrasound imaging was used as the reference standard to validate fetal movements. The wearable system detected binary fetal movements with more than 90% accuracy in the in-hospital trial setting.

Before human testing, the researchers validated the sensors using artificial two-dimensional and three-dimensional abdominal models, simulating fetal kicks from different depths and directions. The findings, published in Science Advances, demonstrate that the wearable can reliably capture a wide range of fetal movements while filtering out noise caused by maternal motion.

The wearable patch is intended to complement, not replace, standard clinical assessments. Continuous at-home monitoring could help parents feel more informed between appointments and support earlier detection of concerning changes in fetal movement patterns. The researchers plan to conduct larger clinical trials in out-of-hospital and home settings and to pursue regulatory pathways for broader clinical and community use.

“Reduced fetal movement is one of the most common reasons patients present to hospital, yet we rely heavily on self-reporting,” said Associate Professor Vinayak Smith. “A comfortable, continuous monitor has real potential to give us clearer information and help expectant parents feel more confident between appointments. This is a promising tool for maternity care.”

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