Why do we use fetal monitoring in labour?
During labour, a midwife or doctor caring for you will perform various assessments to ensure labour is progressing well for you and baby. One of these assessments is listening to baby’s heartbeat.
During labour when the uterus (womb) contracts, the maternal blood does not flow as freely through the placenta and your baby has a reduced oxygen supply. This is normal and most babies are able to adjust without any problems. However, if your baby is having difficulty in adjusting this may be reflected in the pattern of the heartbeat. Listening to the baby’s heartbeat regularly enables midwives or doctors to detect this.
What are the different methods of fetal monitoring available?
When monitoring a baby’s heartbeat, the midwife or doctor will first assess your pulse to ensure they can differentiate between the two.
There are two main methods of monitoring a baby’s heartbeat.
- Intermittent auscultation
- Continuous cardiotocography (CTG)
What is intermittent auscultation?
Intermittent auscultation is when a midwife uses a handheld Doppler ultrasound machine or a pinard stethoscope to listen to the baby’s heartbeat. This is carried out immediately after a contraction for at least one minute. During labour, this is performed every 15 minutes, increasing to every five minutes during what is known as the second stage of labour, or the ‘pushing’ stage.
Intermittent auscultation is recommended for monitoring babies of women whose pregnancy is classified as ‘low risk’. This means there are no risk factors identified in your medical or obstetric history that mean involvement of an obstetrician is advised. Your midwife will regularly reassess this to ensure you are receiving the care you need. Therefore, if there are any concerns that arise during labour, the midwife will discuss changing to continuous cardiotocography with you.
What is continuous cardiotocography (CTG) monitoring?
Continuous monitoring records the baby’s heartbeat throughout the whole of the labour period. This is carried out by using an electronic fetal heart rate monitor known as the CTG machine. Elastic belts are used to hold the sensors onto your abdomen; one sensor monitors the baby’s heartbeat while the other sensor monitors the frequency of contractions.
This is then recorded on a strip of paper, referred to as the CTG or trace. The CTG is also linked to the computer system so there is a digital copy, this allows the midwifery and obstetric team to have an up-to-date monitoring of baby’s heartbeat which can be seen outside of the labour room.
The midwife will constantly interpret the trace to monitor how well the baby is coping in labour. They will also perform a formal interpretation every hour with another midwife or doctor, known as ‘fresh eyes’. This is good practice to ensure two members of the maternity or obstetric team regularly discuss and agree on the findings of the CTG trace. Therefore, please be aware that an additional member of staff will enter the labour room every hour to perform this with the midwife.
If you have been advised that your pregnancy is classed as ‘high risk’ then continuous cardiotocography will be advised. For example, if during pregnancy there is known:
- high blood pressure
- multiple pregnancy
- previous caesarean section
- small for gestational age baby
Or in labour there is:
- suspected infection
- significant meconium-stained liquor
- abnormal observations e.g. raised temperature
- delay in labour e.g. requiring an IV drip to speed up the labour process
- use of epidural analgesia
As continuous monitoring will require the CTG transducers on your abdomen to be attached to the machine, this can limit your mobility slightly. However, we can offer Telemetry monitoring to be able to facilitate mobilisation during labour.
If there is any concern regarding the quality of the fetal heartbeat recording, for example there is loss of contact for prolonged periods of time, or the midwife/doctor has concerns with the baby’s heartbeat then a fetal scalp electrode may be discussed and recommended to ensure good quality monitoring of the baby’s heartbeat.
As with all aspects of your care, if the midwives or obstetricians have identified any concerns with the CTG or baby’s heart rate, then this will be discussed with you and your birth partners. We encourage you to ask anything about the baby’s heart rate or any concerns or questions you may have.
What is a Fetal Scalp Electrode (FSE)?
A fetal scalp electrode (FSE) is a small clip that is attached to the baby’s scalp to record the baby’s heartbeat. With your consent, the midwife or doctor will perform a vaginal examination to attach the FSE to the baby’s scalp with their fingers. A lead then runs from the clip to the CTG machine. The FSE does not harm the baby but sometimes there may be a small graze where it was applied on the baby’s head after birth. This will heal quickly but has a small risk of infection.
What is telemetry monitoring?
Telemetry monitoring is a wireless fetal monitoring device linked to the CTG monitor. It is carried out in the same way as the CTG monitoring however it is wireless. This is beneficial to enable you to be able to mobilise freely during labour and to adopt different positions that are comfortable for you.
Fetal monitoring in water
Women who are using water during labour, such as the birthing pool, require intermittent auscultation with a handheld Doppler ultrasound or a pinard stethoscope. Continuous cardiotocography (CTG) or telemetry cannot be used in water. Therefore the use of birthing pools is not recommended for women who are advised to have continuous cardiotocography (CTG).
Shared Decision Making
At the Queen Elizabeth Hospital Maternity Unit, we advocate a shared decision making approach to all decisions made by our patients. This leaflet aims to give you additional information and to act as a point of reference following a discussion with your obstetrician or midwife. If you are asked to make a decision about your own care please make sure you have asked all the questions you need to ask and are given the appropriate time to do so. Some questions you might want to ask could be;
- What are my options?
- What are the pros and cons of each option?
- Who will support me making the decision that is the right one for me
If you have any additional queries please contact:
Pregnancy Assessment Unit
Any personal information is kept confidential. There may be occasions where
your information needs to be shared with other care professionals to ensure you receive
the best care possible.
In order to assist us to improve the services available, your information may be used for
clinical audit, research, teaching and anonymised for National NHS Reviews and Statistics.