Electronic fetal monitoring in labor is a routine practice in most countries such as the US, UK and Australia.
Many women would be surprised to know there is no evidence to support the use of this form of monitoring.
Even more surprising is the link between the use of electronic fetal monitoring (EFM) and c-section birth.
Electronic Fetal Monitoring And C-Section
The evidence for the effects of EFM and the link with c-section has been around for three decades.
Very few pregnant women are aware of the link, or the lack of support for the use of EFM during labor.
What Is EFM?
Electronic fetal monitoring (EFM) uses special equipment to measure the fetal heart rate response to contractions during labor. EFM provides a continuous record which can be read at the time of labor and kept afterwards.
There two types of EFM – external and internal.
External EFM involves two belts wrapped around your belly, to measure the length of contractions and the time between them, as well as to detect your baby’s heart rate.
Internal EFM involves placing a wire called an electrode on your baby’s scalp. The electrode records the baby’s heart rate. A special tube called an intrauterine pressure catheter can be inserted through your vagina and into the uterus to monitor contractions. Internal EFM is only possible after your amniotic sac has broken, which might be done artificially.
EFM provides a print out, or electronic recording, of the fetal heart rate and the mother’s contractions together. The monitor looks at the baseline fetal heart rate and how it’s affected by contractions. It records any increases in heart rate (accelerations), any decreases (decelerations), and also checks the frequency and length of maternal contractions.
You can read more about this in Baby’s Heart Rate During Labor – What’s Normal And What’s Not.
The EFM recording is reviewed at set times by your care provider, more frequently if an abnormal rate is detected.
Why Is EFM Used?
Electronic fetal monitoring was introduced into practice in the 1970s. Marketing of EFM as a scientific breakthrough that could detect fetal distress led doctors to think EFM would prevent oxygen deprivation to unborn babies during labor, and therefore prevent cerebral palsy.
During this medical era, it was believed cerebral palsy was caused by lack of oxygen during labor, although later research showed the link between the two was very rare. Clinical trials were not conducted before EFM was introduced because it was considered unethical to deny the expected benefits to the controls in the trials.
Over time, the use of EFM increased:
- 1980 – 45%
- 1988 – 62%
- 1992 – 74%
- 2002 – 85%
- Today – 90%
In the late 1980s, however, after large research trials it was established there were no benefits from EFM.
The Lancet published a review of 8 trials that showed there were no benefits to fetal health or outcomes. What the studies did show was the only significant, constant effect of continuous EFM was to increase the rate of c-section.
Further research since has confirmed EFM doesn’t improve birth outcomes but rather leads to an increase in c-section rates. Between 1970 and 2016, the c-section rate in the US increased from 5% to 32%.
The rate of cerebral palsy hasn’t changed since the widespread use of EFM during labor. It has been suggested this is because in the majority of cases cerebral palsy occurs before labor has started.
A 2013 review looked at 23 studies to see how often lack of oxygen during birth was linked to cerebral palsy. The review found most cases of cerebral palsy were caused by factors present during pregnancy before labor began, which couldn’t be prevented by EFM.
EFM has no clinical benefits to mothers or babies, but it is routinely used in many hospital settings around the world, often presented as compulsory for admission into maternity wards.
Why Is EFM Still Done?
Despite this lack of evidence for improving outcomes, EFM is still very much a part of many hospital labor wards today. There are two key reasons why this is the case.
The first reason is because of a mindset that says: we have the technology, so let’s use it. During the last 100 years, pregnancy and birth have shifted from being viewed as normal events in a woman’s life, to medical events requiring assistance and intervention. We have access to more interventions than ever before – inductions, episiotomies, c-sections, forceps, and EFM.
The more we use technology, the less risk we believe is involved. There has been a huge shift from continuity of care (with a known care provider) to an endless conveyor belt of hospitals.
Women are no longer routinely cared for by their local doctors or midwives during pregnancy and birth. In hospitals, midwives often care for more than one woman at a time during active labor, and the use of EFM helps care providers monitor from a distance rather than give hands on care.
The second reason EFM is still used, despite the lack of supporting evidence, is care providers believe it protects them from liability if a baby is born with cerebral palsy.
If a lawsuit is brought against a hospital or care provider after a baby is born with cerebral palsy, failure to have a record of the fetal heart rate can be seen as a failure to provide standard care, despite the knowledge that EFM isn’t best practice or even evidence based care. Losing a medical negligence lawsuit can cost care providers a lot of money.
How Does EFM Increase C-Section Rates?
The use of EFM is routine in the US, and in many other countries it is required on admission and intermittently (every hour for 20 minutes) during active labor. So how can EFM be linked to increasing c-section rates?
EFM requires a woman to wear belts that restrict her movement and might even tether her to the hospital bed, in a lying down position. This can cause increased pain and stress, interrupt the normal process of labor and potentially increase the possibility of false readings, or non reassuring fetal heart rates.
After ‘failure to progress’, this is the second most common reason in the US for a first time c-section. Lying down can compress a major vein, which reduces oxygen to the baby. This can show up as fetal distress.
With hands on listening, care providers have to be more present with the laboring woman. They can’t rely on a machine to monitor their charge and they must also actually look at and touch the laboring mother, which conveys the benefits of having a continuous support person.
Although relying on a machine to monitor laboring women might be more convenient from a staffing perspective, it also comes at a cost.
Research has shown continuity of care through labor decreases the risk of c-section and increases the chances of many positive outcomes. Continuous support also offers women benefits such as less pain and increased satisfaction with their birth experience.
What Does This Mean For Me?
In many birth settings, women who are having a low risk pregnancy are told EFM is a requirement on admission to hospital, then during labor, either continuously or intermittently.
There is no evidence, however, to show EFM improves outcomes for mothers and babies. The benefits of EFM are for care providers who are under pressure to care for multiple women and to maintain hospital requirements.
In any situation, women should be provided with the evidence to show EFM is clinically necessary – meaning it will improve outcomes for mothers and babies.
A study from 2017 found there was an increased risk of c-sections in women who had EFM on admission to hospital. The study review included more than 13,000 low risk women. The women who had EFM on admission were more likely to end up having continuous EFM for the rest of their labor, with the attendant increased risk of c-section.
Research supports the use of hands on listening, rather than EFM, as the preferred method of monitoring babies during labor. However, many hospitals and care providers aren’t able to provide hands on listening as they’re neither trained nor experienced in its use, or do not have the correct equipment. Many midwives are trained in the use of EFM and, because of the pressure of the hospital environment, prefer it over hands on listening.
Ultimately, you can refuse EFM but you might have no alternatives to fetal monitoring if your care provider or birth setting can’t accommodate hands on listening.
Who Should Have EFM?
In the US, the American College of Obstetricians and Gynecologists (ACOG) recommends hands on listening as appropriate and safe for low risk women. They also suggest care providers be trained to monitor using a handheld Doppler, to facilitate freedom of movement and enhance women’s comfort.
Similarly, in the UK, the National Institute for Health and Care Excellence (NICE) recommends care providers do not offer EFM to low risk women during labor. The NICE guidelines recommend hands on listening be offered instead.
Healthy women with a healthy baby might want to explore alternatives to EFM for fetal monitoring during labor. In a home birth situation, a private midwife might use a fetal stethoscope or a handheld Doppler.
However, many guidelines don’t recommend hands on listening for women with the following complications:
- Bleeding during labor
- Suspected fetal growth restriction
- Previous c-section
- Multiple babies
- Breech birth
- High BMI
- Pre or post term labor (before 37 weeks and after 42 weeks)
- Premature rupture of membranes
- Induction with synthetic oxytocin (Syntocinon or Pitocin)
It’s important to remember these complications haven’t been studied comparing EFM with hands on listening, so we don’t know whether either method would actually benefit women and babies in these situations.