Why fetal monitoring

The provider may put another device over the top of your belly with a belt. This is called an external tocodynamometer. It can record the patterns of contractions. In some cases, you may need internal fetal monitoring for a more accurate reading of the fetal heart rate. This can only be done if your bag of waters amniotic sac is broken and your cervix is partly open dilated. The provider puts a small wire called a fetal scalp electrode through your open cervix. The electrode is attached to a wire.

After external fetal monitoring, the provider removes the straps and wipes the gel off your belly. Search Encyclopedia. Fetal Monitoring What is fetal monitoring? Or it can be done directly on the baby while inside your uterus internal monitoring : External monitoring. Why might I need fetal monitoring? What are the risks of fetal monitoring? 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 low 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. 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 detecting 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 asphyxia , or 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. 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 quality evidence than randomized trials, because the studies could be showing a decrease in stillbirths during labor over time called a secular trend , not 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, the meta-analysis of randomized trials shows that continuous EFM does not have an effect 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.

The authors concluded that the use of a handheld Doppler device is a more reliable test for abnormal fetal heart rates than intermittent EFM or the use of a Pinard fetal stethoscope. They also note that handheld Dopplers are simple, affordable, and probably cause less discomfort than Pinard fetal stethoscopes. In contrast, it appears that intermittent EFM alone when not combined with other monitoring methods is not based on research evidence. So, some researchers have concluded that it should not be recommended Martis et al.

There is very little research on wireless or mobile continuous electronic fetal monitors. Two small pilot studies in Uganda and the U. Birthing people in these studies reported that they like the mobility that they had with the wireless monitors.

Both studies experienced some data loss and delays from wireless connection problems. As we mentioned, there are a variety of devices that can be used for hands-on listening during labor. Cochrane researchers conducted a review and meta-analysis to find out which types of listening tools and timing protocols are most effective Martis et al. They were only able to find two randomized, controlled trials to contribute data to the meta-analysis.

The studies were conducted in Zimbabwe and Uganda and included a total of 3, participants. When the two studies were combined, they found that a handheld Doppler battery and wind-up is linked to more Cesareans for abnormal fetal heart rate compared to a Pinard fetal stethoscope, but without a clear difference in newborn health outcomes low Apgar scores, newborn seizures, or perinatal death.

However, the quality of the evidence is low and other important newborn health outcomes were not assessed. There is not enough evidence at this time to recommend a Doppler ultrasound or a type of fetal stethoscope as the preferred listening device. Researchers have looked into the evidence for this practice. They found four studies from the U. Altogether, the studies included more than 13, low-risk participants. The researchers found a tendency towards more Cesareans among the people randomly assigned to EFM on admission compared to those assigned to hands-on listening on admission, but the finding was not statistically significant.

This means that more data is needed before we can detect if there is a real impact of admission EFM on Cesareans. People assigned to EFM on admission were more likely to end up being put on continuous EFM for the rest of their labor. There were no differences in newborn health outcomes between the groups, including newborn seizures. You may find the elastic belts that hold the transducers in place slightly uncomfortable.

These can be readjusted as needed. You must lie still during some types of fetal heart rate monitoring. You may need to stay in bed during labor. With internal monitoring, you may have some slight discomfort when the electrode is put in your uterus.

Note: You should not have internal fetal heart rate monitoring if you are HIV positive. This is because you may pass the infection on to your baby. You may have other risks depending on your specific health condition.

Be sure to talk with your provider about any concerns you have before the procedure. Certain things may make the results of fetal heart rate monitoring less accurate.

These include:. You may have fetal heart rate monitoring in your healthcare provider's office or as part of a hospital stay. The way the test is done may vary depending on your condition and your healthcare provider's practices. You do not need any special care after external fetal heart monitoring. You may go back to your normal diet and activity unless your healthcare provider tells you otherwise.

The provider will clean the site with an antiseptic. Health Home Treatments, Tests and Therapies. Why might I need fetal heart monitoring? Fetal heart rate monitoring may be used in other tests, including: Nonstress test. This measures the fetal heart rate as your baby moves.

Contraction stress test. This measures fetal heart rate along with uterine contractions. Contractions are started with medicine or other methods.

A biophysical profile BPP. But electronic fetal monitoring is linked to a greater chance for vacuum and forceps use, and for C-section delivery. Talk with your healthcare provider about these risks. Getting ready for fetal monitoring depends on if it is external or internal. It also depends on if it is being done late in pregnancy or during labor. For external fetal monitoring during pregnancy with a Doppler, you may need to have a full bladder.

There is no restriction of food or drink. Make sure to ask questions if needed. For fetal monitoring during labor, your healthcare provider will tell you if any preparation is needed. The provider will put gel on your belly. This helps to send sound waves from your belly to the computer.

The provider puts a device called an ultrasound probe transducer on your belly.