During your labor and birth, your doctor or midwife will be monitoring your baby’s heart rate to assess their well-being during labor and birth. The goal of using electronic fetal monitoring is to recognize babies who are short on oxygen and identify what the underlying cause is to correct it. Monitoring heart rate can also alert a doctor or midwife in the event an emergency arises in which a baby needs to be born immediately via cesarean section or through an assisted birth. Electronic fetal monitoring may sound uninteresting, but it can have a significant impact on your labor and birth. You have some choices about monitoring, depending on your risk level and how you and your little one are doing during labor.
Article and Resources
The Purpose of Fetal Monitoring
During your labor, your doctor or midwife will be monitoring the heart rate of your baby. From your care provider’s standpoint, this is the best way to track your baby’s well-being during labor and alert your doctor or midwife if there is a problem.
The Standard of Care
Electronic fetal monitoring is standard procedure in hospital labor and delivery units. According to ACOG, in the most recent year (2002) for which data are available, 85% of births in the United States used electronic fetal monitoring. Its use has steadily increased over the past decades, from 45% in 1980. Electronic fetal monitoring is the most common obstetric procedure. Since it is so ingrained in the medical model, a lot of the research and evidence on EFM is dated. (Like the figure from 2002 above that has not been updated in nearly two decades.) You typically see a lack of more recent research when we have answered all of the questions on a topic with sufficient scientific evidence. The problem with the practice of EFM is there are still questions about whether this practice is evidence-based, even though it has become the standard of care in the United States.
Normal Heart Rate
Your baby’s normal heart rate baseline can be anywhere between about 110 to 160 beats per minute. A baseline of more than 160 beats per minute is tachycardia. A baseline lower than 110 beats per minute is bradycardia.
Your baby’s heart rate is constantly changing. This constant change is the variability or beat-to-beat variation. A healthy beat-to-beat variation is generally 5-25 beats per minute. There are some instances in which your baby’s heartbeat will speed up. These fetal heart accelerations happen when they move in the womb when your doctor or midwife is feeling your belly and putting pressure on it to determine your baby’s position, or if your provider touches your baby’s head during a vaginal exam. You can see that some variations are common and are no big deal.
How Your Baby’s Heart Rate Changes During Labor
Labor and birth are going to be the most physically stressful events of your baby’s life. The reason for this is that each time you have a contraction, the blood flow to the placenta is temporarily diminished, and this reduces your baby’s oxygen supply. This might sound scary, but this is normal and how we are designed to work. The decrease in oxygen supply to the placenta is short, and the oxygen supply will increase as soon as your contraction is over. Your body is designed to do this, and your baby is built to cope with this. When you have a contraction and the supply of oxygen is to the placenta is reduced, your baby’s heart rate slows down, and then returns to their regular heart rate after the contraction is over. Again, this is normal, and you should not worry about it.
A doctor or midwife identifies fetal distress by significant changes in a baby’s heart rate. Remember, your care provider is monitoring heart rate as a measure of your baby’s well-being.
Before birth, babies rely on the umbilical cord and the placenta to supply their oxygen. If a baby is not receiving enough oxygen in the womb, their heart rate will decrease. The goal of using electronic fetal monitoring is to identify babies who are short on oxygen and pinpoint the underlying cause to correct it.
Metabolic acidemia happens when your baby is deprived of adequate oxygen for over 60 minutes and is associated with increased rates of neonatal morbidity, specifically cerebral palsy. According to the CDC, the prevalence of cerebral palsy ranges from 1.5 to more than 4 per 1,000 live births. This condition is caused by abnormal development of the brain or damage to the developing brain that affects a child’s ability to control their muscles. 85%–90% of cases of cerebral palsy are congenital. Of all of the cases of congenital cerebral palsy, only 6% are attributed to birth complications that disrupt the oxygen supply. If you are concerned about your baby developing this condition as a result of diminished oxygen during birth, please know this is an infrequent occurrence.
For fetal heart rates that are decelerating or slowing down some examples of measures to correct it is to change your position, give you oxygen, change the medications you are given or discontinue Pitocin, or to alleviate compression of the umbilical cord. A tachycardic heart rate could be a sign of an infection, hyperthyroidism, or placental abruption.
Monitoring heart rate can also alert your doctor or midwife in the event an emergency arises in which the baby needs to be born immediately, either via cesarean section or through an assisted birth. Detecting an abnormal fetal heart rate does not always mean there is a problem. Before jumping into a cesarean, your care provider will be trying to find out what the underlying cause is. In some cases, something as simple as changing the position you are in can allow your baby to get more oxygen.
The American College of Obstetricians and Gynecologists has clinical guidelines that are very specific as to what is considered normal. They break down readings into three tiers. Category I is healthy and comes with routine care. Category III tracings mean that your baby is not getting enough oxygen, and your care provider will be working to do everything they can to identify the issue and correct it. If the measures they are taking are not working, it is likely they will recommend immediate delivery. Category II is everything in between categories I and III. With category II, your care provider is continuing to watch and evaluate to make sure your baby does not progress to category III.
Recommendations from the American College of Obstetricians and Gynecologists
ACOG recommends that during the first stage of labor, fetal heart rate tracings should be reviewed every 30 minutes. Once you are in the second, pushing stage, they should be reviewed every 15 minutes. This is the frequency with which your care provider should be looking at the results from an electronic monitor, not necessarily how frequently the measurements are being taken.
Types of Fetal Monitoring
The method of monitoring your baby’s heart rate depends on your doctor or midwife, the policy of the venue where you are giving birth, your risk of complications, and how your labor is progressing. Your care provider monitors your baby’s heart rate through one of two methods; auscultation or electronic fetal monitoring.
Auscultation is a method of periodically listening to the baby’s heartbeat. This is usually done with a Doppler transducer, but your care provider may also use a fetal stethoscope, or a Pinard, which is a trumpet-shaped device that amplifies sound. In most cases, a Doppler is used, and this device kind of looks like a microphone, and when it is held up to your belly, you can hear the heartbeat amplified through a speaker. Chances are you have seen this at one of your prenatal appointments.
In general, with intermittent monitoring, they will be checking about every 15 minutes during the first stage of labor, when you are dilating, and during the second stage of labor, or the pushing stage, they will be checking more frequently, probably about every five minutes. The frequency of this could be more frequent. Ultimately it is up to your care provider to decide how often they want to check your baby’s heart rate.
Electronic Fetal Monitoring
Electronic Fetal monitoring uses instruments to continuously record the heartbeat and the baby and the contractions of the uterus during labor. The machine used is a cardiotocograph, or CTG, and more commonly known as an electronic fetal monitor. A CTG provides an ongoing record so your care provider can go back and look at the results of how your contractions and the baby’s heartbeat have changed over time. This record can either be a printout or just show up on a screen.
External and Internal Electronic Monitoring
Electronic Fetal Monitoring can be external, internal, or both. With external monitoring, a pair of belts are wrapped around your abdomen. One of the belts is using a Doppler to detect your baby’s heart rate, and the other belt measures the length of contractions and the time between contractions. This is by far the most common method of monitoring. It is not considered invasive because the belts are just strapped around your belly, but you will be connected via wires to the CTG machine so you may not be able to move or walk around too much. There are some instances in which external monitoring is not working well or if your doctor or midwife has some concern and wants a more accurate reading. In this case, your care provider may recommend internal monitoring.
With internal monitoring, a wire, called an electrode, is placed on the part of the baby closest to your cervix, usually their scalp, and this records the heart rate. A tiny screw holds the electrode in place. Your contractions may also be monitored intermittently by using an intrauterine pressure catheter. This is a tube that is inserted through your vagina into your uterus. Internal monitoring is only used after your water has broken, and you are dilated at least 1-3 centimeters. One reason for doing internal monitoring could be that you are having twins, in which they want to make sure they can differentiate the heartbeat of each baby, usually referred to as baby A and baby B. Another reason for internal monitoring is if mom is significantly overweight, in which case it can be tough to detect a heartbeat with an external monitor.
Internal monitoring is not a routine procedure, and your care provider will only be using this if there is cause to do so. With internal monitoring, there is a slight risk of infection and the possibility that the electrode can cause bruising on your baby. There may also be some discomfort when the electrode is put in your uterus. Keep in mind, this method of monitoring your baby’s heart rate is not the most common. Generally, if your care provider is recommending it, there is an excellent reason to utilize an internal monitor. There are some instances in which internal monitoring is not recommended, and this would be if you are HIV positive or if you have an active herpes infection. With internal monitoring, you will be required to stay in bed and will not be able to move around very much.
Monitoring at Home or in a Birth Center
If you have a home birth or a birth center birth, chances are you will be monitored intermittently via auscultation, meaning with a Doppler and without a CTG machine. If you have your baby at a hospital, you may have some options for monitoring and whether it is intermittent or continuous. Some reasons your care provider may prefer continuous monitoring is if you get an epidural, or you have Pitocin, which is synthetic oxytocin to induce or augment your labor, or if you are high risk or run into any complications. A few examples of things that could make a pregnancy high-risk include diabetes or high blood pressure, or if your baby is not developing or growing as well as they should be.
Consideration for Electronic Fetal Monitoring
You are probably thinking, well, why wouldn’t I want to be hooked up to a monitor that is making sure my baby is doing well? That’s a good question, and there some reasons why some expecting parents may want to minimize or avoid continuous monitoring if that is an option for you.
Monitoring Upon Hospital Admission
If you have a hospital birth, you will probably be hooked up to a monitor for about 20-30 minutes once you arrive at the hospital in labor. If everything is going well, you may be able to have the belts removed and just hook it up intermittently. One study found no evidence of benefit for the use of an electronic fetal monitor upon admission to a hospital. It also found that this practice increases the cesarean section rate by approximately 20%. The findings of this review support recommendations that the admission CTG not be used for women who are at a low risk upon admission. It goes on to recommend that women should be informed that admission CTG is likely associated with an increase in the incidence of a cesarean section without evidence of benefit.
Effects on Mobility
One big issue with electronic fetal monitoring and continuous monitoring is that it impacts your ability to move around because you are tethered to a machine with wires. There is a lot of evidence that the best labor positions are not lying on your back in a hospital bed. The ability to move around and try different positions may help your labor progress. Some labor positions may even shorten your labor.
Also, continuous electronic fetal monitoring may not allow you to labor in the shower or to have a water birth. If you plan to utilize water therapy, please talk to your doctor or midwife about your monitoring options and how that works with baths or showers.
One other option you may have is telemetry monitoring. A telemetry monitor uses a transmitter on your thigh to transmit the baby’s heartbeat via radio waves. It is usually transmitted to a nurse’s station so you can be walking around and have much more mobility while you are in labor and still have constant monitoring. Not all hospitals will have a telemetry monitor available, but if it is something you are interested in, you can ask your care provider if this is an option. A mobile monitor would allow you much more mobility than a standard CTG machine.
Continuous vs. Intermittent Monitoring
Electronic fetal monitoring is often continuous, but it doesn’t necessarily have to be as long as you and baby are doing well. Ultimately this is something you will need to discuss with your care provider. Your doctor or midwife is on your team. The two of you will be working together to have a healthy and safe labor and birth and get as close as possible to the birth experience you want. If you want to know what your options are for monitoring the heart rate of your baby during labor, talk to your doctor or midwife and find out what their policy is and what the policy is where you are planning to have your baby. Ask if they foresee a need for you to have continuous monitoring or if a telemetry unit will be available as an option. It is all about balancing what you want with ensuring the safety of you and your baby, so work with your care provider to find solutions that work for you and your specific situation.
Monitoring and COVID-19
Due to the current environment with COVID-19 at the time of this article, many hospitals are implementing continuous monitoring. The reasons for this are that it minimizes the frequency staff has to enter your labor room. Continuous monitoring solves two issues. One that anytime a doctor or staff member enters your room, you and your partner may be required to put a mask on, which could be disruptive. Secondly, if hospitals are dealing with shortages in staff, this allows monitoring to take place by fewer people in a central location, rather than by many individuals assigned to each room. As long as hospitals are affected by COVID-19, we may see additional changes in protocols to procedures during labor and birth. You can always ask your doctor whether recent changes due to COVID-19 will impact your labor and birth.
Tips for Electronic Fetal Monitoring
If you do opt for electronic monitoring, I have some tips to improve your experience. There is a volume on an electronic monitoring machine. If you find it distracting, you can always turn the volume down, or even turn the monitor away, so you are not looking at it. You may find it helpful to pay attention to it, or it may just be a distraction. You want your partner paying attention to you, not the machine, and if it is a distraction to them, you can turn it down or turn it away.
If you are listening to the heart rate and it suddenly stops, do not panic. The transducer probably just shifted out of place, and a nurse or your care provider should be able to adjust it. If you are paying attention to the machine, don’t panic if there are changes in your baby’s heart rate. We talked earlier about some changes being completely healthy. Your focus should be on meeting your baby, not trying to be a pro at reading the results of the monitor.
The Evidence on Continuous vs. Intermittent Electronic Fetal Monitoring
What does the research say about electronic fetal monitoring? I will link to a Cochrane review of 13 trials and over 37,000 women that compared intermittent monitoring with continuous monitoring. Overall, there was no difference in the number of babies who died during or shortly after labor. Neonatal seizures in babies are very rare and occurred less often with continuous monitoring. There was no difference in the incidence of cerebral palsy. The research showed that continuous monitoring was associated with a significant increase in cesarean and instrumental vaginal births. I was not able to sufficient evidence to 100% support continuous electronic monitoring for all mothers in labor.
Monitoring a High-Risk Pregnancy
Electronic fetal monitoring is almost always used in situations where the baby is considered high risk. This makes sense on the surface, but there is no hard evidence that continuous electronic fetal monitoring has improved outcomes for babies in high-risk pregnancies. This is echoed in the Cochrane Review mentioned above.
Why Hospitals Use EFM
With all of the research we have reviewed, you may be asking the question, “Why do hospitals use continuous electronic monitoring?” There are many reasons why this is a standard protocol, and here are a few:
- This is a practice that has been in place for decades and is ingrained in the medical model.
- OBGYN students and nurses are taught how to monitor labor with continuous EFM and how to read the results. They may not be trained in how to monitor intermittently, or via auscultation.
- There has been some speculation that this is used for liability reasons to provide data to help against malpractice lawsuits for birth complications. Although, because the use of continuous EFM has been found to increase the rate of cesarean births, this may not be effective in reducing litigation.
- This allows practitioners to monitor labor progress without being physically present in the room. This requires fewer staff members to monitor more patients.
As with any birth intervention, electronic fetal monitoring should come with informed consent. After reading this article, you have a lot of knowledge to talk to your doctor or midwife about your options and preferences for monitoring your baby’s heart rate during labor. There are both pros and cons to any type of monitoring, and you should discuss how this can impact your birth with your care provider. You do have options, and you can exercise your right to decline or request a specific type of monitoring. This is a decision you should make with your doctor or midwife after taking into account the particulars of your pregnancy.
Including Preferences for Monitoring in Your Birth Plan
This may be something you would like to include in your birth plan. If you want to see a sample of a birth plan and how you can include electronic fetal monitoring, I am happy to send you a copy of mine. Your preferences will be different, I am sure, but it will at least give you a good idea of how you can word and structure a birth plan. To request a free copy, please click here.
Thank you to BLUblox for their support of this episode.
BLUBlox makes the best blue light blocking glasses and you can save 15% with the promo code PREGNANCY. Your circadian rhythms drive your hormones and you want to be blocking blue light after the sunset. Blue light can affect everything from your fertility to your breastmilk and these glasses mitigate the risks of blue light exposure at night. To check them out click here and use the promo code PREGNANCY to save 15%.