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Interviews with 12 obstetricians recognized for their scientific and clinical contributions in the use of electronic fetal monitoring EFM revealed notable areas of agreement and disagreement in the interpretation and use of these methods. Fetal Monitoring In Practice 2e For the set of FHR patterns studied, scalp blood pH sampling was recommended more often to confirm conservative management of labor than to verify the need to intervene. The obstetricians may be classified by their degrees of 1 alarm and 2 interventionism, and by their 3 frequency of and 4 motivation for scalp sampling. Associations among these four dimensions of behavior were limited.
All Rights Reserved. Leer en Espanol. The information that health care providers get from fetal heart patterns during labor helps them decide whether or not to intervene in the birth process.
In this article, we cover the evidence for the different types of fetal monitoring and their pros and cons. We also explore the history of fetal monitoring, barriers to evidence-based care, and ways to improve the current situation. Continuous electronic fetal monitoring usually means you have to stay on or near the hospital bed. The monitor is assessing the baseline fetal heart rate and how it changes with contractions.
Many hospitals routinely use continuous electronic fetal monitoring during labor. Some people interpret this language to mean that hospital staff should actually watch EFM tracings continuously. If the person giving birth has risk factors, then assessment and charting of the EFM tracings may be done as frequently as every minutes. Monitors are also usually set to alarms, so staff are notified when the heart rate is abnormal or the monitor is not picking up the heart rate.
Some hospitals have wireless, waterproof electronic fetal monitors. Unlike traditional fetal monitors, some wireless monitors like the Novii are water resistant can be used in the shower Fetal Monitoring In Practice 2e while the birthing person is laboring in upright, active positions away from a hospital bed. Intermittent means using something at regular time intervals, and not using it continuously. Intermittent electronic fetal monitoring, although fairly common, hardly has any research evidence backing its use.
Some hospitals have their own definitions of intermittent EFM; however, we could not find any professional guidelines that recommend how to use intermittent EFM during labor. Another fetal monitoring option is intermittent Fetal Monitoring In Practice 2ewhich we call hands-on listening. With hands-on listening, the care provider listens to the fetal heart rate for short periods of time at regular intervals. They document the fetal heart rate, rhythm regular or irregularany fetal heart rate accelerations, and the depth, timing, and duration of any decelerations Smith et al.
Most guidelines state that hands-on listening should be done for at least 60 seconds at a time, at least every minutes during the active phase of the first stage of labor and at least minutes during the pushing phase of the second stage of labor ACNM The Society of Obstetricians and Gynecologists of Canada proposes that hands-on listening be done at first assessment and about every one hour during early labor Liston et al.
See the list of resources at the end of this article for links to several professional guidelines for hands-on listening protocols. Hands-on listening with a fetal doppler can be done in any laboring position, even under water with some devices. There are several different devices that can be used for hands-on listening during labor Lewis et al. The most popular option in the U. The fetal Doppler detects the fetal heart motion and converts it to sound, which can be heard out loud.
Fetal Monitoring In Practice 2e features of Fetal Monitoring In Practice 2e fetal Doppler include:. The Cascade Allen Type fetal stethoscope is another option for hands-on listening.
The metal headband allows the listener to be hands-free. So instead, he rolled sheets of paper into a tube and listened through this device. The paper listening tool was later made in wood to become the first wooden stethoscope. The first fetal electrocardiogram EKG recording took place in Heelan InDr. Continuous electronic fetal heart rate monitoring was introduced into hospitals in the s without evidence from clinical trials, but with a strong marketing push from the monitoring industry Obladen The machine was marketed as a scientific breakthrough that could predict fetal distress and bring an end to cerebral palsy—still the most common motor disability in childhood CDC It was embraced by most obstetricians and nurses.
Women were not informed at the introduction of EFM in the s that its use was totally experimental.
Today, the use of continuous EFM machines is widespread, although, as you will see, it is still lacking evidence of benefits Sartwelle et al.
As the use of EFM during labor increased, so did the Cesarean rate, and it is possible that these two trends are connected. Between andthe Cesarean rate in the U. ACOG InCochrane researchers combined the results of 12 randomized, controlled trials including more than 37, participants Alfirevic et al. Most of the studies were of poor quality and took place in the s and s. Both technology and clinical practice have changed over the years and we do not know what effect this would have on the results if these studies were re-done today.
In all of these studies, people were randomly assigned to receive either continuous EFM or hands-on listening during labor. The researchers found no differences between the continuous EFM group and the hands-on listening group in Apgar scores or cord blood gases, rates of low-oxygen brain damage, admission to the neonatal intensive care unit, or perinatal death.
They also found no difference between groups in the percentage of people using medication for pain relief during labor. The overall findings were consistent for people with both low-risk and high-risk pregnancies. When the researchers removed the poorer quality trials from the analysis it did not change the overall findings.
The risk of a newborn seizure was 0. The overall Cesarean rate varied widely between the different studies—it ranged from a low of 2. However, two-thirds of the data on Cesarean rates in the meta-analysis came from the study with an extremely Fetal Monitoring In Practice 2e Cesarean rate of 2.
In the meta-analysis, the absolute risk of Cesarean was 3. Of course, the overall Cesarean rate is much higher in most settings today. This means that there would be one additional Cesarean for every 11 women monitored by continuous EFM. In addition, as many as women would have to be monitored with continuous EFM to prevent one newborn seizure. This amounts to an estimated 61 unnecessary Cesareans from continuous EFM in order to prevent one newborn seizure event.
As you can see, the risk-benefit debate focuses on preventing Cesareans vs.
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They found that in hospitals where there are higher Cesarean rates, continuous EFM leads to an even higher risk of Cesarean. The Cochrane review did not find a difference in the rate of cerebral palsy between the continuous EFM group and the group who received hands-on listening. Other researchers have found that continuous electronic fetal monitoring is a very poor test for Fetal Monitoring In Practice 2e potential cerebral palsy.
False positive rates for predicting cerebral palsy are as high as Put another way, most positive test results will be wrong. The false positive rate is so high that for every 1, fetuses with an abnormal heart rate pattern that indicates cerebral palsy is at risk of occurring, only one or two will go on to develop cerebral palsy ACOG A poor screening test for a rare outcome could be considered unethical, since it can cause healthy people to think they are sick, lead to unnecessary medical tests and procedures with harmful side-effects, and waste money and other resources.
The rate of cerebral palsy has stayed the same over time, despite the widespread adoption of using EFM during labor. About one out of children have been diagnosed with cerebral palsy since Van Naarden Braun et al. A review published in looked at 23 studies to determine how often birth asphyxiaor a lack of oxygen during birth, is linked to cerebral palsy Ellenberg and Nelson They found that only a minority of cerebral palsy cases are linked to birth asphyxia.
In other words, most cerebral palsy cases are due to prenatal factors before labor begins, and cannot be prevented by EFM.
Some researchers think that another basic assumption of EFM may also be faulty Lear et al.
Med Decis Making. ;2(1) Electronic fetal monitoring and clinical practice. A survey of obstetric opinion. Cohen AB, Klapholz H, Thompson MS.
A healthy fetus may be able to adapt to brief but repeated periods of low oxygen during contractions by triggering something called the peripheral chemoreflex. This theory would help to explain why many babies are born healthy despite repeated brief decelerations during labor. If this theory is correct, it means that what qualifies as normal fetal heart rate patterns during labor is broader than previously thought. Rates of intrapartum death stillbirth were already falling when continuous electronic monitoring was introduced in the s Hornbuckle et al.
This makes it difficult to interpret the evidence from observational studies. A review by Hornbuckle et al. In addition, nine out of nine observational studies comparing labors monitored with continuous EFM vs. On average, the stillbirth rate in low-risk monitoring groups was lower by about 0. Studies of this type provide lower Fetal Monitoring In Practice 2e evidence than randomized trials, because the studies could be showing a decrease in stillbirths during labor over time called a secular trendnot caused by the introduction of continuous EFM.
There may also be publication bias, where researchers are more likely to publish studies which show falling death rates. On the other hand, there could be a true relationship between continuous EFM and lower stillbirth rates.
As we discussed earlier, Fetal Monitoring In Practice 2e meta-analysis of randomized trials shows that continuous EFM does not have an Fetal Monitoring In Practice 2e on stillbirth or newborn death Alfirevic et al.
The limitation with randomized trials, however, is that a rare outcome like stillbirth requires a very large sample size to detect a difference between groups. The Cochrane reviewers estimate that more than 50, women would have to be randomly assigned to continuous EFM or hands-on listening in order to detect a difference in one death out of 1, births. Since the Cochrane analysis only included around 37, participants, there is a chance that continuous EFM has an effect on stillbirth that was not detected.
If continuous EFM leads to a decrease in stillbirths during labor, it does not necessarily mean that continuous EFM should be used all the time for all laboring people. Any decrease in the risk of stillbirth during labor would be very small, especially among low-risk births, while the known increase in Cesarean rates with continuous EFM is very large Hornbuckle et al.
There have only been two randomized trials on this topic:. In one study, researchers in Sweden randomly assigned more than 4, low-risk participants to receive either continuous EFM or intermittent EFM Herbst and Ingemarsson They defined intermittent EFM as being on the monitor for 10 to 30 minutes every two to two-and-a-half hours during the active first stage of labor plus the use of hands-on listening every minutes in between EFM periods.
So, in other words, the intermittent EFM group also had hands-on listening. In the second stage of labor, all of the participants were monitored continuously with EFM. The researchers found no differences in any outcomes. There has only been one randomized, controlled trial that compared intermittent EFM alone with hands-on listening alone Mahomed et al. In this study, 1, low-risk participants giving birth at a hospital in Zimbabwe were randomly assigned to either intermittent EFM or one of three different methods of hands-on listening—Doppler ultrasound, Pinard fetal stethoscope used by a research midwife, or Pinard fetal stethoscope used by the attending midwife as was routine in that hospital.
Intermittent EFM was defined as wearing the sensors for the last 10 continuous minutes of every 30 minutes if the results were normal, or the last 10 continuous minutes of every 20 minutes if the results were abnormal.
However, the Doppler ultrasound group had the best newborn health outcomes overall. The research midwives in the study used Huntleigh pocket Doppler ultrasound monitors to listen to the fetal heart rate during the last 10 minutes of every half hour, especially before and immediately after a contraction.