The 'worst test in medicine'? Doctors know it doesn't work—so why are we still using it?

Every clinician knows the pattern: A test becomes standard practice, embeds itself into workflow, and persists for decades—even after evidence shows it doesn’t do what we thought it did. Few examples illustrate this better than continuous electronic fetal monitoring (EFM), one of the most enduring and outdated tests still used routinely in American medicine.

Here’s the uncomfortable truth: The most ubiquitous screening tool in U.S. labor units has an abysmal track record of improving outcomes—and a stellar record of driving up interventions.

The New York Times recently called it “the worst test in medicine.”^[] Hyperbolic? Maybe. Inaccurate? Not really. Let’s talk about why.

The history behind continuous fetal monitoring

First widely adopted in the 1970s, fetal heart monitoring was intended to help doctors identify signs of fetal distress, such as oxygen deprivation, which could lead to life-threatening complications.

The case against continuous fetal monitoring

Emmet Hirsch, MD, an obstetrics professor at the University of Chicago, has gone so far as to label fetal monitoring “the worst test in medicine.” ^[] The core problem is the high variability of fetal heart rates.

Healthy babies often exhibit fluctuating heart rates, which can easily be misinterpreted as distress, prompting unnecessary interventions such as emergency C-sections. These surgeries, while intended to protect the baby, come with significant risks, including infection, hemorrhage, and complications in future pregnancies.

Why do we still use continuous fetal monitoring?

Despite these well-documented shortcomings, continuous fetal monitoring remains the standard of care in US hospitals, largely due to legal and financial pressures.

Simply having the monitor in place can serve as a protective shield for doctors in litigation, regardless of its actual efficacy in improving patient outcomes.

What the future holds

This reliance on fetal monitoring has sparked criticism within the OB/GYN community. Jennifer Lincoln, MD, an advocate for evidence-based medicine, has spoken out against the technology, calling it something that many obstetricians are “stuck with,” despite its lack of proven benefits.

In an Instagram post, Dr. Lincoln explains how some practitioners continue to use fetal monitoring out of habit or fear of litigation, while others are beginning to question its value and push for more individualized, evidence-based care.

While continuous fetal monitoring remains widespread in the US, other countries, such as Canada and the UK, have moved away from its routine use, especially in healthy pregnancies.

As the debate continues, it’s evident that a shift in obstetric care is necessary. The overuse of fetal monitoring is contributing to an increasing number of unnecessary C-sections, which pose significant risks to both mother and baby.

The obstetric community must re-evaluate the role of continuous monitoring, placing a higher priority on patient safety and birth outcomes rather than legal and financial concerns. ^[]

Steven Clark, MD, an obstetrician at Baylor College of Medicine, sums it up aptly: “We may be the only specialty that continues to do major abdominal surgery without a shred of evidence of benefit.” ^[] It's time for a more thoughtful and evidence-driven approach to childbirth.