2 Monitoring the fetal heart rate during labour
7. What are the stages of labour?
- The first stage of labour: From the onset of labour until the cervix is fully dilated.
- The second stage of labour: From full dilatation of the cervix to the complete delivery of the infant.
- The third stage of labour: From complete delivery of the infant to complete delivery of the placenta.
The first stage of labour can be divided into the latent and the active phase. The latent phase progresses to the active phase when the cervix is more than 3 cm dilated.
8. Should the fetal heart rate always be monitored in labour?
Yes, if the fetus is alive and viable. If the fetus is dead or believed to be too small and immature to survive, there is no reason for monitoring the fetal heart during labour.
9. Should the fetal heart rate be monitored throughout labour?
Yes. The fetal heart rate should be regularly monitored from the onset of labour until complete delivery of the infant, i.e. throughout the first and second stage of labour. Often the fetal heart rate is forgotten about during the second stage of labour. This is a serious error.
The fetal heart rate should be monitored throughout labour.
10. How can the fetal heart rate be monitored?
- With a fetal stethoscope (Pinard fetal stethoscope).
- With a fetal monitor (Doppler ultrasound fetal heart rate monitor).
- With a cardiotocograph (CTG) machine. This may use either an abdominal Doppler ultrasound probe or an electronic fetal scalp clip. It also monitors the contractions using a pressure transducer. A fetal monitor and cardiotocograph both use an ultrasound transducer to detect and count the fetal heart rate.
11. What are the advantages and disadvantages of a fetal stethoscope?
- Easy to obtain
- No maintenance
- Often difficult to find and hear the fetal heart
- Often difficult to count the fetal heart rate
- Uncomfortable for the mother, especially during a contraction
The fetal stethoscope is widely used, especially in under-resourced services. However, the disadvantages make it unsatisfactory as it is difficult to reliably and accurately count the fetal heart rate, especially in obese women.
There are important disadvantages to using a fetal stethoscope.
12. What are the advantages and disadvantages most fetal monitors?
- Easy to find and accurately determine the fetal heart rate
- The fetal heart rate is displayed on a digital screen
- Comfortable for the mother and reassuring as she can hear her fetus’s heart
- Promotes contact and support by the midwife
- Requires disposable batteries or mains electricity source
- Often difficult to repair and service
- Monitoring is intermittent, not continuous
There are important advantages to using a fetal monitor to assess the fetal heart rate.
13. What are the advantages and disadvantages of a cardiotocograph?
- Very accurate
- Provides a paper record
- Continuous fetal monitoring
- Easy to identify different types of fetal heart rate deceleration and assess fetal heart rate variability
- Expensive to buy and maintain.
- Recording paper is expensive.
- Difficult to use and often not used correctly
- Difficult to read the tracing correctly.
- Needs trained and experienced staff.
- Mother has to remain in bed
- Requires reliable mains electricity source
- Scalp clips are invasive and contraindicated in HIV-positive women
14. Which method of fetal heart rate monitoring should be used?
In all primary care birthing units and for many women delivering in district hospitals, the fetal monitor is the most cost-effective option. Only when the fetus is at high risk of distress during labour are there advantages of using a cardiotocograph.
A fetal monitor is the best option in primary care birthing units and district hospitals.
15. What are the advantages of the Philips fetal monitor?
In under resourced circumstances the Philips fetal monitor has a number of important advantages when compared with many other fetal monitors:
- It is relatively cheap
- It is very robust and not easily damaged
- It is simple and easy to use
- It has a rechargeable battery which can be charged by main electricity, solar power or by hand cranking. It can even be charged while driving a car.
This range of options ensures that it can always be used even when mains and solar power are not available. It does not need replaceable batteries.
16. Why is it so important to monitor the fetal heart rate during labour?
It is essential to monitor the fetal heart rate during labour in order to assess how the fetus responds to the stresses of labour. The stress of a normal labour usually has no harmful effect on a healthy fetus.
It is essential to monitor the fetal heart rate during labour.