Labor and delivery teams in Philadelphia may soon get an early warning when a routine birth starts tipping toward dangerous postpartum bleeding. A local crew of nurses and engineers has built a monitoring system that reads a laboring mother's heart to catch early signs of uterine "myometrial fatigue," a red flag that can precede postpartum hemorrhage. The tool, called Vasowatch, is designed to buy clinicians hours instead of minutes so they can deliver medicine, line up blood and pull in staff before bleeding turns life threatening.
Leading the charge is Stefanie Modri, a Philadelphia registered nurse and clinical instructor at the University of Pennsylvania, who helped spearhead the project. She told WHYY that "in pregnancy, in any type of blood loss, minutes really, really matter." According to the outlet, Vasowatch looks at heart‑rate patterns during contractions to screen for myometrial fatigue and flag patients who might otherwise be labeled low risk when they are admitted.
How Vasowatch spots risk
Under the hood, Vasowatch runs an algorithm on streaming maternal heart‑rate data pulled from standard wearables, then triggers bedside alerts when its myometrial‑fatigue index climbs. According to Vasowatch, the platform can plug into cleared sensors such as Sibel Health's ANNE chest monitor and push continuous risk updates to dashboards at the nurses' station. The pitch is that it slots into existing labor‑and‑delivery routines so clinicians do not have to overhaul how they watch patients.
Early results and what they mean
An early paper on the system's VIBRANT algorithm found that the software alerted clinicians two to eight hours before delivery and was associated with about a 60% reduction in hemorrhage in its study cohort, results the team presented at CHASE 2025. The need they are targeting is sizable: the American College of Obstetricians and Gynecologists reports that roughly 40% of postpartum hemorrhages occur in patients initially assessed as low risk and defines postpartum hemorrhage as blood loss of 1,000 milliliters or more within 24 hours. If those early lead‑time gains hold up in larger trials, they could translate into fewer transfusions and emergency procedures.
Modri told WHYY the team now has new funding from the National Institutes of Health and hopes to launch a large, multi‑site clinical trial that could support market clearance by 2028. Federal award records on SBIR.gov show Vasowatch previously received an NIH STTR/Phase I award to build the prototype, and company materials say the next step is a roughly 300‑patient pilot to shape a pivotal trial and an FDA pathway. The project has also drawn local commercialization support as it lines up health‑system partners to run pilots.
Penn's commercialization arm lists Vasowatch in its portfolio, and the company says it has letters of intent from several health systems to pilot the technology, underscoring how tightly the work is tied to the city's health‑innovation network. For Philadelphia hospitals and smaller community units dealing with staffing squeezes and blood shortages, a tool that reliably buys clinicians hours could reshape how teams prepare for and respond to postpartum hemorrhage, though experts caution that widespread use will depend on strong, multi‑site evidence.
