Shortage of Scalp Electrodes May Harm Fetuses, Clinicians Warn

Mary Chris Jaklevic

May 23, 2023

This story has been updated to include a statement from Philips

A worldwide shortage of fetal scalp electrodes could reduce access to internal fetal heart rate monitoring, potentially leading to more perinatal deaths and other complications, two ob/gyns in Canada are warning.

The shortage resulted from a recall by Philips of 1.7 million electrodes that attach to babies' scalps for monitoring inside the womb. The device maker notified users in November 2022 that electrodes tips could break off and potentially require surgery for removal.

Daniel Kiely, MDCM, MSc, of the University of Montreal, Quebec, and Lawrence Oppenheimer, MD, of the University of Ottawa, Ontario, write in a pending article that although the recall is "presumably intended to improve safety, the resulting shortage poses risks to patients due to inadequate fetal heart rate monitoring."

The researchers called the electrodes "a critical tool in ensuring a consistently interpretable tracing of the fetal heart rate" when high-quality tracing isn't possible by monitoring externally with transducers attached to the pregnant person's abdomen.

Their article will be published in the American Journal of Obstetrics & Gynecology Maternal-Fetal Medicine . Medscape Medical News obtained a draft from the publisher, Elsevier.

Elevated Risks

With external monitoring, a consistent signal may not be obtainable, particularly in patients who have elevated body mass index or are in the second stage of labor, Kiely and Oppenheimer write.

External monitoring also can mistakenly pick up a maternal pulse or, another fetal pulse in the case of multiple pregnancies, the researchers write. Accurate tracing may not be attainable even by taking recommended steps of repositioning transducers and applying a maternal pulse oximeter, they note, yet a bad reading may appear correct due to technology that "smooths out" the signal when it jumps from one source to another.

Signal ambiguity can mask an abnormal fetal heart rate or even fetal death, they write, and is associated with intrapartum fetal hypoxic ischemic encephalopathy, or loss of blood flow to the brain; stillbirth; neonatal death; and unnecessary caesarean delivery for already stillborn fetuses.

ECRI, an independent, nonprofit patient safety organization, sent an alert to its 3000 members, which include many hospitals, on April 27 warning that fetal scalp electrode shortages could lead to higher rates of elective caesarean deliveries.

Supply Chain Problems

The alert, which ECRI shared with Medscape Medical News, said that Cardinal Health, the only US supplier of electrodes that are compatible with Philips's fetal heart rate monitors, has reported supply problems and does not anticipate having stock until August.

According to the ECRI alert, the US Food and Drug Administration determined that given the supply issues, Philips could distribute some of its recalled electrodes on the basis of clinical need. It said that Philips reports having "less than 30 reports" of tip failures that required surgical intervention.

Philips did not respond to email seeking comment.

Jamila Vernon, senior manager of media relations and communications for the American College of Obstetricians and Gynecologists, said that the society "is not aware of a shortage" and did not have a comment. Lisa Black, the media relations manager for the American Academy of Pediatrics, said that she could not locate anyone in her organization who was familiar with the problem.

Kiely and Oppenheimer cowrote a protocol that recommends internal monitoring as the preferred response when clinicians suspect signal ambiguity, with ultrasound being a last resort.

In their new article, they note that Philips advised internal monitoring as a backup in 2009 as it warned about signal ambiguity in a recall of its fetal heart rate monitors.

"Given that Philips monitors are in use worldwide," the researchers write, the current electrode recall "is undermining the solution to a previous recall."

In response to questions from Medscape Medical News, Philips said:

Philips has become aware of low availability of products comparable to the Fetal Spiral Electrode that until recently had been supplied from other manufacturers, following the November 2022 recall and discontinuance by Philips. We are aware that the current shortage of compatible products is due to a number of factors, including supply chain issues, affecting a number of stakeholders.

Philips is presently in discussions with industry stakeholders regarding whether Philips may potentially contribute to addressing this issue for health care providers with urgent clinical needs. Customers may want to evaluate the supply of FSEs that they have available for patients and contact your supplier to determine when additional products may or may not be available. Philips Fetal Monitoring customers with questions regarding low supplies of compatible products may contact Philips for more information. To help ensure continued availability during this time, we recommend our customers not to discard the reusable leg plate adapters that are used to connect the Philips Fetal Spiral Electrode to the Philips Fetal Monitors.

The decision to undertake the recall was based on a limited number of customer reports regarding the possibility of the spiral tip of the device breaking off during use, and requiring surgical intervention for safe removal. At the time of the recall notification, Philips analysis indicated an observed incidence rate of less than 0.01% of device uses of this type, with no reports of patient death related to this issue.

Kiely reported no conflicts of interest. Oppenheimer received payments for expert opinions in legal cases involving maternal heart rate artefact.

Mary Chris Jaklevic is a healthcare journalist in the Midwest.

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