During labour, your baby will respond to contractions with changes (dips) in her heart rate.
This is very normal. When the dips recover quickly, it shows your baby is coping well with the strength of the muscle squeezing her, and the temporary reduction in oxygen.
Before the invention of the fetoscope, birth care providers had little idea of how babies were doing during labour. The fetoscope allowed midwives to listen to the baby’s heart beat and detect changes.
Technological advances have now made it possible to listen to babies constantly during labour – but is this necessarily a good thing?
What Is Fetal Monitoring?
Fetal monitoring is the term used for listening to your baby’s heart rate during labour. As each contraction happens, the baby’s heart rate will normally slow down, because of the pressure being placed on the umbilical cord.
After the contraction passes, your care provider will expect to hear your baby’s heart rate return to normal. If it remains low, or if there are any abnormal patterns to the heart rate, your care provider might become concerned your baby’s oxygen supply is being compromised. There is an increased risk of this happening if your labour is induced with a medication.
As a side note, one third of babies are born with a cord around the neck, due to their movements in the womb. It’s rarely a cause for concern, because babies receive oxygen from the cord and don’t breathe through their nose. Find out more about a nuchal cord (cord around the neck).
Why Is Fetal Monitoring Important?
Monitoring your baby’s heart rate can help your care provider to detect changes which can indicate whether there is a problem or not.
A normal fetal heart rate indicates all is well and your baby is coping with labour. If changes are detected, such as your baby’s heart rate remaining low after a contraction or abnormal patterns, your care provider will look at what is causing this.
Fetal monitoring can identify abnormal heart rates early so action can be taken if your baby needs to be born quickly. This may be necessary to prevent complications which result from oxygen deprivation, such as brain damage, seizures, cerebral palsy, or death.
Find out more about a baby’s heart rate in labour – what’s normal and what’s not. Knowing some basics about baby’s heart rate can save you a great deal of stress and worry in the heat of the moment.
How Can We Hear The Fetal Heartbeat?
There are a number of ways your baby’s heart rate can be monitored during labour. The method used will depend on whether your care provider and hospital have access to, and experience with, the different types of fetal monitors:
- Electronic Fetal Monitor. Two belts are strapped to your belly. One picks up your baby’s heart rate and the other records the frequency and strength of your contractions. These belts are connected to a monitor and while you are hooked up, they will restrict your movement. The monitor provides a read out, which is checked by your care provider.
- Internal Electronic Fetal Monitor. If your cervix is dilated enough and your waters have broken, an electrode is inserted through your vagina, and punctures your baby’s scalp. The wires are taped to your thigh. This monitoring is the most accurate, but requires you to lie reasonably still so the wires aren’t pulled out.
- Telemetry. This method of monitoring uses the same sound wave technology as external monitoring. A transmitter is attached to your thigh to transmit the baby’s heart rate to the nurse’s station. This method allows you freedom to move, but is not widely available.
- Fetoscope and Pinard Horn. These devices are similar to a stethoscope, but listen to your baby’s heart rate instead of heart tones. The sound is subtle, and the devices need to be correctly positioned. Not all care providers have the skill and experience to use them effectively.
- Doppler or Doptone. This is a handheld ultrasound device. It enables experienced users to pick up heart tones within a minute. The device places no restriction on your movement. Some Dopplers can be used in water, so you can labour in a birth pool without needing to get out to be monitored.
What Are The Different Types of Monitoring?
There are two methods to monitor fetal heart rate during labour:
- Auscultation or intermittent monitoring means listening to the heartbeat periodically during labour. Intermittent monitoring is performed with a fetoscope, Pinard horn or Doppler. These instruments are placed on your belly for around a minute at set times during during active labour. If you are at risk for complications or problems develop during labour, your baby’s heart rate may be checked more often.
- Electronic fetal monitoring (EFM) is used if there is a need to record to your baby’s heart rate and your contractions continuously. EFM provides a constant record which can be reviewed by your care provider as frequently as needed. EFM can be performed externally or internally.
How your baby’s heart rate is monitored depends on a number of factors, including your risk status during pregnancy, the policy of your hospital or care provider, and if there are any complications during your labour.
Will Fetal Monitoring Interfere With Labour?
Intermittent monitoring means your care provider will monitor you for a minute or two at set intervals. This shouldn’t interfere with your labour, as you can usually remain in whatever position you are in, or in the birth pool/shower. You only need to keep still for the time the heartbeat is being detected.
Electronic fetal monitoring can make it more difficult for you to remain active and mobile during labour, unless your hospital has a telemetry monitoring unit. If EFM is required, you may still be able to utilise different positions other than lying on a bed.
You can sit in a chair or on a birth ball, as well as stand, kneel or even squat. Ask your care provider to support you to find positions that allow movement but don’t interfere with the monitoring equipment. You may also be able to leave the EFM for intervals, to use the toilet or shower.
Why Is Electronic Monitoring Used More?
Fetal monitoring is a way of detecting possible problems before they become serious enough to cause severe complications for your baby. It is often assumed electronic fetal monitoring EFM) is the best method to prevent problems but research doesn’t bear this out.
A Cochrane review looked at the results of 12 trials with over 37 000 women, which compared electronic fetal monitoring with intermittent monitoring. The studies showed there was a lower risk of newborn seizures with EFM but the overall risk was very low (around 1 in 500).
There was no difference between in the number of babies who died during or after birth, APGAR scores, cerebal palsy or other indications of newborn wellbeing. However EFM was linked to an increased risk of instrumental vaginal birth and c-section.
Electronic fetal monitoring doesn’t reduce the number of perinatal deaths or improve newborn wellbeing, but it does increase the chances of an instrumental birth and c-section.
Depending on your personal health situation and birth setting, you might not have much choice about the method and type of monitoring offered to you during labour. It’s important to discuss with your care provider the risks and benefits of monitoring, especially if you are low risk and you want to achieve a normal vaginal birth.
Recommended Reading: When Doctors Don’t Listen – Informed Consent When Giving Birth.