Cover Story: Avoiding 5 common mistakes in FHR monitoring

Key Points

It's hard to imagine a more basic component of obstetric care than fetal monitoring. While there's little evidence that continuous electronic fetal heart rate monitoring (EFM) during labor improves clinical outcomes, when compared with intermittent auscultation, EFM has essentially replaced auscultation in most American Labor and Delivery units. As a labor-saving device for nursing care and as a way to generate a permanent record of fetal heart rate (FHR) patterns, it would appear EFM is here to stay.^1.2

Given this reality, it is very important to follow certain standard procedures when using EFM. In our highly litigious society, the L&D unit is often the target of malpractice suits. And since EFM does produce a permanent record, the "strip" becomes a critical piece of evidence in many of these cases, with experts for all parties arguing over the significance of the various changes in the FHR.

To provide the best patient care, while at the same time avoiding the nightmare of litigation, clinicians need to avoid at least five common errors, which we'll discuss further on.

Most women receiving EFM during labor are connected to an external device that records both uterine activity and FHR. The technology in the newer fetal monitors has improved significantly; for many patients an excellent recording of both the FHR and uterine contractions is obtained with external monitoring. Of course, the tracing may be lost with changes in the mother's position, but it's readily re-established.

Often patients and caregivers would prefer to avoid internal monitors because they're invasive, unnatural, and have certain inherent risks, and in fact they are frequently unnecessary. Keep in mind, however, there is one clinical setting in which an internal monitor should be considered: for the patient who has progressed to the second stage and begins pushing. During this period of time, an external monitor often will only intermittently record the FHR. Despite various nursing efforts, an adequate continuous tracing may be difficult or impossible to obtain.

Despite this fact, clinicians frequently do not place a fetal scalp electrode. Doing so would eliminate the difficulties involved in external monitoring and more importantly, one can obtain a continuous FHR tracing both between as well as during maternal pushing efforts. This allows for prospective review of the tracing with the ability to better gauge fetal status and tolerance to labor. And finally, replacing external with internal monitoring sidesteps the problem of missing periods of fetal heart tracing that occur with external EFM. When an adverse outcome occurs with the newborn, those gaps can easily lead to allegations of negligent monitoring directed against both the physician and the nurses.

2. DISCONTINUING the MONITOR TOO EARLY

In this scenario, the patient is progressing to a point where delivery is thought to be imminent. The health-care team decides to remove a previously placed fetal scalp electrode or external monitor. However, for whatever reason, the patient doesn't deliver for several minutes and many subsequent pushing efforts. Then an unexpectedly depressed newborn is delivered and the caregivers realize that there's been no fetal monitoring at all for a protracted period.

This sequence of events raises several questions regarding possible acute and unrecognized changes in fetal status and it also means there may have been a lost opportunity to have identified a need to shorten the second stage of labor. In addition, the option to have neonatal and respiratory support for the depressed newborn at the time of delivery never was thought necessary, as such an outcome was not expected.

3. CONFUSING the MATERNAL and FETAL HEART RATES

Because external EFM uses ultrasound and interprets the changes in frequency of the reflected energy, it is not uncommon for the monitor to actually record the maternal and not the FHR. This fact is well-known by those who have been taught fetal monitoring, and it is usually readily recognized and corrected. Indeed, basic to such monitoring is the continuous need to distinguish the maternal heart rate from the FHR.³ This is a problem unique to external monitoring, assuming a living fetus.