Routine continuous electronic fetal monitoring, a.k.a., cardiotocography, during labor continues to be the norm in labor & delivery units despite being a colossal failure, and the obstetric community knows it. This is a shocking, but provable, statement. To do that, this post will:
- Summarize the research
- Explain why continuous fetal monitoring not only doesn’t work but can’t work
- Quote fetal monitoring guidelines
As for where that leaves you, the “Take Away” will provide strategies on how you can work the system, including how to:
- Obtain intermittent listening
- Minimize the use of continuous monitoring
- Make an informed decision about switching to continuous monitoring
- Minimize the potential harms of continuous monitoring
Let’s start with a look at the evidence.
What Does the Evidence Say?
The theory behind routine continuous fetal monitoring goes like this: Abnormal fetal heart rate patterns are strongly associated with stillbirth, newborn death, and neurologic injury, in particular, cerebral palsy, but while listening periodically to the fetal heart rate detects these abnormalities, intervening rarely averts these outcomes. The problem must be too little information, too late. A machine that can track the fetal heart rate and its response to contractions should enable doctors to recognize trouble sooner and rescue babies before damage is done. And by identifying distressed babies more accurately, it should also avoid unnecessary cesarean and instrumental deliveries.
The theory sounded so good that it was put into practice without testing it. By the mid-1970s, routine continuous fetal monitoring was in widespread use before ever conducting a single trial comparing its outcomes with intermittent listening.
It turned out the theory didn’t hold up. When trials were finally conducted in the 1980s and into the mid-1990s, only one, an extremely problematic Greek trial funded by a fetal monitor manufacturer, reported the benefits that were claimed for it. When data from the trials are pooled (systematic review), the evidence is clear:1 continuous fetal monitoring doesn’t reduce the incidence of death during labor or in the days after birth (perinatal mortality) or the incidence of cerebral palsy or any long-term adverse neurologic outcome. It doesn’t even reduce incidence of poor condition at birth, and it increases, not decreases, cesarean and instrumental deliveries. Continuous monitoring also interferes with mobility, increases discomfort, and pulls attention away from the laboring woman, and internal monitoring requires rupturing membranes, which has its own harms. In other words, routine continuous fetal monitoring isn’t just not beneficial, it’s harmful.
Continuous fetal monitoring has only one advantage: It reduces the number of newborns having seizures,1 but this isn’t as meaningful as it sounds. For one thing, there were no long-term ill effects. For another, newborn seizure is extremely rare—1 per 1000 newborns in low-risk women—which means the increase is miniscule. To prevent 1 newborn from having seizures, 883 low-risk women would have to undergo continuous monitoring. For a third, seizure rate depends on labor management policies. Two large trials (13,000 to 14,000 women), one in Dublin, one in Dallas, illustrate this: The Dublin trial took place in a hospital that practices “Active Management of Labor,” a policy that includes elements (routine rupture of membranes and high-dose oxytocin to augment labor) that increase stress on the baby. The Dublin trial reported a seizure rate of 4 per 1000 newborns with intermittent listening whereas the Dallas trial reported a rate of only 4 per 10,000 newborns. In Dublin, 417 women would need to be continuously monitored to prevent one seizure, but in Dallas, the number is over 3300. Finally, the increase in cesareans with continuous monitoring more than offsets any benefit in reducing seizures. Assuming a cesarean rate of 15% in low-risk women with intermittent listening, 1 excess cesarean surgery will be performed for every 6 women being continuously monitored.1
You would think continuous monitoring’s failure to reduce mortality or permanent neurologic injury would have given obstetricians pause, but it didn’t. They simply decided that the problem was execution, not the validity of the theory, and set about in the ensuing decades to try to make continuous fetal monitoring work. They came up with any number of fixes and studied them intensively, including:
- To increase reliability, monitoring the fetal heart rate and contraction pressure internally via an electrode that catches under the baby’s scalp and a pressure sensor inserted into the uterus.4, 11
- To improve diagnostic accuracy, standardizing definitions of heart rate patterns and describing their implications.25, 31
- To decrease subjectivity, having a computer analyze the tracing.6
- To increase information, using the scalp electrode to record an electrocardiogram in addition to heart rate patterns.24
- To better discern which babies are or are not tolerating labor, taking a blood sample from the fetal scalp and analyzing it for chemical indicators of distress when the fetal heart-rate pattern is abnormal.1
- To cut down on false positive diagnoses of fetal distress in healthy babies, performing 20 minutes of continuous monitoring at hospital admission to identify which babies bear closer watching and which can be monitored with intermittent listening.8
The research results were consistent and unequivocal: not one of these solutions made the slightest difference.
It has been said, “When you discover that you are riding a dead horse, the best strategy is to dismount,” but obstetricians have yet to back off from routine continuous monitoring. (If you’re interested in why obstetricians continue to cling to a failed technology, scroll down to “Taking a Deeper Dive.”)
The reason continuous fetal monitoring doesn’t do what the theory says it will do and the fixes don’t change that is because the theory behind it is wrong. Let’s look at that next.
Why Doesn’t Routine Continuous Fetal Monitoring Work?
Continuous fetal monitoring doesn’t work because it can’t work. The theory behind it is based on the premise that stillbirth and newborn death and permanent neurologic disability are largely caused by insufficient oxygen in labor and that abnormal fetal heart rate patterns are tightly linked to poor long-term outcome. But that isn’t true. For one thing, insufficient oxygen during labor isn’t a major cause of disability or death.20 For another, the chain between fetal heart rate abnormalities and severe adverse outcomes is weak at every link. Abnormal fetal heart rate connects weakly with condition at birth,1, 2, 7, 17, 19, 21, 23, 27, 32, 37 which connects weakly with neurologic symptoms at birth,10, 13, 17, 18, 21, 38 which connects weakly with death or permanent impairment.29 If every intermediary link in the chain is weak, then the link between abnormal fetal heart rate and severe adverse outcome is pretty much nonexistent.
There are other issues as well:
- If the injury occurred prior to labor, continuous monitoring may or may not signal the problem, but even when it does, rescue delivery will make no difference.
- Problems such as fever during labor, administering sodium deficient IV fluids or too much sugar in IV fluids, or drinking excessive amounts of fluids can cause the same symptoms as low oxygen,3, 9, 12, 14, 16, 22, 28, 35, 36 but if low oxygen isn’t the problem, delivery isn’t the solution.
- Some catastrophic events occur too quickly for rescue delivery even when detected immediately.
- Many hospitals don’t have the 24/7 staffing and resources to handle an urgent cesarean. Even when they do, the ability to perform an urgent cesarean is defined as 30 minutes from “decision to incision,” which may be too long for acute situations.
- Some aspects of labor cause fetal heart rate alterations that look problematic but are harmless, including fetal activity, fetal sleep, and drugs such as opiods that cross the placenta.1
If the theory behind continuous monitoring is unsound, attempts to fix it amount to rearranging deck chairs on the Titanic.
We’ve looked at the research, which disconfirms continuous monitoring, and disproved the theory behind it. Now, let’s turn to what obstetric authorities recommend.
What Do Fetal Monitoring Guidelines Recommend?
Fetal monitoring guidelines issued by authoritative sources are in line with the evidence:
“For a woman who is at term in spontaneous labor with a fetus in vertex presentation, labor management may be individualized (depending on maternal and fetal condition and risks) to include techniques such as intermittent auscultation.” — American College of Obstetricians & Gynecologists (2019)
“Implement intermittent monitoring policies for low-risk women.” — California Maternal Quality Care Collaborative (2016)
“Do not perform cardiotocography for low-risk women in established labour.” — Royal College of Obstetricians & Gynaecologists (U.K.) (2014)
“Routine use of cardiotocography is not recommended.” — Queensland, Australia Government (2018)
“Monitor pregnancies greater than 37 weeks 0 days’ gestation in healthy women in spontaneous labor without perinatal risk factors via intermittent auscultation.” — Society of Obstetricians & Gynecologists of Canada (2020)
“Continuous cardiotocography is not recommended for assessment of fetal well-being in healthy pregnant women undergoing spontaneous labour.” — World Health Organization (2018)
Clearly, the obstetric establishment cannot claim ignorance of routine continuous monitoring’s failure. Yet despite the original research finding no benefits, later research showing that modifications don’t change that fact, the provably false premise of the theory, and authoritative fetal monitoring guidelines rejecting routine continuous fetal monitoring, it remains standard practice in most hospitals, which brings us to . . .
Because continuous fetal monitoring remains the norm, you have your work cut out for you if you want to minimize unnecessary exposure to it. Here are some ways to do that:
Strategies during pregnancy: Hopefully, you are reading this early enough in pregnancy that you are still exploring your options, but if you are further along, don’t be afraid to make a switch if you realize that the care isn’t what you want. It’s almost always a better choice than sticking with what you’ve got and hoping for the best.
- Health permitting, plan to have your baby at home or in a freestanding birth center. If you’re not in a hospital, continuous fetal monitoring is a non-issue.
- Choose a hospital that has one-to-one nurse-to-laboring-woman ratios for women in active labor, where intermittent listening is either the norm for low-risk women or staff are willing to accommodate you, and that doesn’t do admission test strips. You can ask about staff to patient ratios and fetal monitoring policies on the hospital tour or by calling the hospital and asking the intrapartum nursing manager or charge nurse.
- Choose care providers whose standing orders are intermittent listening for low-risk women or where all its members are willing to accommodate you. A midwife group may be the better bet. If this isn’t attainable, see if you can get agreement from one of the care providers. If you can, find out how you can ensure that whoever attends the birth will abide by that agreement.
- Choose care providers who only induce labor for medical reasons. Labor induction is an indication for continuous fetal monitoring. Many practitioners encourage inducing labor routinely at 39 weeks of pregnancy or for other non-medical reasons such as estimating that the baby will be bigger than average. You can, of course, decline elective induction, but enthusiasm for labor induction is a tipoff to practice style in general. Again, a midwife practice may be the better bet.
- Plan to cope with labor by means other than an epidural. Like induction, epidural analgesia is also an indication for continuous monitoring. You and your partner should take a childbirth preparation course aimed at preparing you for labor without pain medication, and you may wish to hire a doula, a trained, experienced woman who provides 1-on-1 continuous emotional and physical support. Planning to avoid an epidural doesn’t mean you can’t change your mind in labor.
Strategies during labor:
Provided you and your baby are healthy and labor begins on its own, politely . . .
- Decline an admission test strip.
- Insist on intermittent listening. It may help to show that you are being reasonable to discuss under what circumstances you would agree to continuous monitoring.
But what if the battle seems likely to generate more ill will than you are willing to risk?
- Agree to an admission test strip but find out the duration and follow up when the time is up. If the nurse doesn’t return within a few minutes of that time, ring the call button. A non-confrontational strategy is to ask if she saw anything on the monitor strip that raised concern, and if she says, “No,” ask for the monitor to be discontinued.
- Negotiate for periods off continuous monitoring. At a minimum, ask to use the bathroom and labor in there for as long as you can get away with it.
- Agree to external monitoring only
Strategies for making an informed decision:
What if your care provider wants to switch to continuous monitoring?
- Use the BRAIN acronym to get the information you need to make an informed decision: Benefits, Risks, Alternatives, Intuition/instinct, No or not now. You are entitled to know any proposed treatment’s benefits and risks, including how likely the adverse effect is to occur and whether this treatment creates the need for further medical intervention. You are also entitled to know your alternatives, including watching and waiting, and the benefits and risks of those. After processing that information, you may wish to consider what your intuition or instinct is telling you. Most importantly, you have the right to say “no” or “not now.” If you do, it’s a good idea to discuss the circumstances under which you would change, or consider changing, your mind.
What if your care provider wants to switch to internal monitoring?
- Ask: “What information will you get that could change my care that you aren’t getting now? If the amniotic sac is still intact, the potential harms of rupturing membranes should weigh heavily in your decision. (See below under “Strategies to minimize harms when there is concern about fetal status.”)
Strategies to minimize the harms of continuous monitoring:
Sometimes continuous monitoring is indicated—or cannot be avoided without being labeled as a “difficult patient.” Here are some ways to minimize its potential harms:
- Request telemetry monitoring. Wireless monitoring broadcasts data to a central monitoring station, which enables you to be up and around because you’re not tethered to a machine.
- Don’t allow monitoring to inhibit you from moving around and changing position. In bed, you can sit up, lie on your side, get on hands & knees, or squat. You can also sit in a chair, stand upright or lean over the bed and do pelvic rocking, or slow dance—rock from foot to foot—in your partner’s arms. Be creative. And don’t let the nurse’s need to readjust the monitoring sensor inhibit you.
- Turn off the monitor sound and turn it away from you or cover it with a towel. The lights and sounds of the monitor can be an attractive nuisance, engaging the attention of your support people and distracting you. If you find that to be the case, you may wish to turn off the sound and turn the monitor away from you or throw a towel over it.
- Request that your care providers follow the Society of Obstetricians & Gynecologists of Canada recommendations for continuous monitoring (Dore 2020, p. 317):
- Induced labor: Provided the fetal heart-rate tracing is normal and the oxytocin dose isn’t being increased, allow up to 30-minute respites from continuous monitoring so that women can walk, shower, etc.
- Continuous monitoring because of maternal or fetal risk factors: Provided both mother and baby’s conditions are stable, allow up to 30-minute respites from continuous monitoring so that women can walk, shower, etc.
- Continuous monitoring initiated in response to an abnormal fetal heart-rate pattern: Provided no maternal and fetal risk factors are identified and the tracing has returned to normal for at least 20 minutes, intermittent listening can be reinstated.
Strategies to minimize harms when there is concern about fetal status:
When there is concern about the baby, here are some strategies that can help minimize harms and confirm that the concern is justified:
- Weigh the benefits of internal monitoring against the harms of rupturing membranes if the amniotic sac is still intact. Because you can’t compress a liquid, releasing the amniotic fluid increases the force of the contractions on the baby. If the baby is already having trouble tolerating contractions, rupturing membranes could make things worse. On the other hand, internal monitoring may provide a more accurate picture of what is going on and a better means of evaluating whether measures being taken to relieve distress are working.
- Barring an emergency . . .
- Ask that someone listen to the fetal heart rate to confirm that the monitor is reporting correctly and to crosscheck that it isn’t picking up your heartbeat instead. Machines can have technical problems, and it is also possible for the monitor to pick up your pulse, which would be alarmingly slow compared with that of a baby before birth.
- Ask for a digital fetal scalp stimulation test to ascertain the baby’s status. During a vaginal exam, the attendant gently rubs the baby’s scalp. A baby whose heart rate accelerates in response is almost certainly fine.5, 30
- Ask that measures to alleviate abnormal fetal heart rate be tried before agreeing to instrumental or cesarean delivery. If it’s not an emergency, you have time to try to resolve the problem by strategies such as changing your position or reducing or stopping the oxytocin IV drip.
Taking a Deeper Dive
Why has routine continuous fetal monitoring persisted when decades of evidence show it doesn’t work?
Several motivations drive continued use of continuous fetal monitoring, none of which relate to improving maternal and child health.
- Entrenchment in obstetric management and in the design and function of labor & delivery units:
“Present-day obstetricians cannot undo 40 years of practice and well-engrained clinical habits.”34
- Protection in litigation cases:
“It gives you a nice hard copy and I think that suits everybody, it just settles your mind and you’ve got proof and with intermittent you have no copy.”33
- Belief in the value of high tech:
“When you look at anything that has lights and a digital readout and a paper drum turning and an instantaneous fetal heart rate recording . . . it makes you feel like you’re getting a lot of information.”15
- Economics of providing adequate staffing:
“It is logistically and financially easier to use the fetal heart-rate monitor than to provide one nurse for each mother in labor.”26
Fetal Monitoring Guidelines
American College of Obstetricians & Gynecologists. ACOG Committee Opinion No. 766: Approaches to Limit Intervention During Labor and Birth. Obstet Gynecol 2019;133(2):e164-e73.
Dore S, Ehman W. Society of Obstetricians & Gynecologists of Canada No. 396-Fetal Health Surveillance: Intrapartum Consensus Guideline. J Obstet Gynaecol Can 2020;42(3):316-48 e9.
National Institute for Health & Care Excellence (NICE). Intrapartum care. Care of healthy women and their babies during childbirth; 2014.
Queensland Clinical Guidelines. Normal Birth. Queensland, AU; 2017.
Smith H, Peterson N, Lagrew D, et al. Toolkit to Support Vaginal Birth and Reduce Primary Cesareans: A Quality Improvement Toolkit. Stanford, CA: California Maternal Quality Care Collaborative; 2016.
World Health Organization. WHO Recommendations. Intrapartum Care for a Positive Childbirth Experience. Geneva: World Health Organization; 2018.
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