pros and cons of CTG

Last reviewed 12/2022

CTG has replaced intermittent auscultation during labour because the ear is insensitive to subtle changes in foetal heart rate.

Additional information gleaned by cardiotocography includes the degree of variation of the heart rate and the shape of accelerations and decelerations.

The value of cardiotocography is questioned. Studies show that it results in increased rates of surgical intervention, including:

• caesarean section during the first stage of labour
• instrumental vaginal delivery during the second stage

CTG is undoubtedly more restricting for the mother than intermittent auscultation.

However, cardiotocography has been shown to lower the rate of neonatal convulsions in prolonged, induced or augmented labours. Unfortunately, the subsequent prevalence of cerebral palsy in those patients is no lower than with other methods of intrapartum monitoring.

The experience with cardiotocography is an example of the frustrations which result from the universal introduction of new techniques without prior randomised control trials. It is now impossible to prove or disprove the value of the CTG