CTG Interpretation

A wide range of clinical investigations are available to healthcare professionals to monitor the condition of a fetus in the womb from early pregnancy to birth. They range from the use of a Pinard's stethoscope, which allows direct auscultation of the fetal heartbeat, to ultrasound imaging of the fetus, which gives an ever-increasing amount of data about the unborn child. Specific 'intrapartum fetal monitoring' techniques are used during the high risk period just prior to birth. Current techniques rely predominantly on the use of electronic fetal monitoring (EFM) through the use of cardiotocography (CTG). This technique records changes in the fetal heart rate (FHR) and their temporal relationship to myometrial activity and uterine contractions. The interpretation of the data collected depends on the relationship between the two traces. The aim is to identify babies who may be hypoxic, so additional assessments of fetal well-being may be made, or the baby delivered by caesarean section or instrumental vaginal birth (1).

CTG was incorporated into clinical obstetrics to reduce intrapartum fetal morbidity and mortality. However, controversies continue regarding the benefits of EFM as opposed to Intermittent Auscultation (IA). From various studies it is concluded that IA is a good as EFM in detecting fetal hypoxia in low risk pregnancy but question regarding advantages in using EFM in high risk pregnancies is still unanswered (1).

Whilst all methods of intrapartum fetal monitoring have their own pit falls, it is conclusively shown that one to one care for a labouring woman is ideal to prevent fetal morbidity and mortality (1). The National Institute of Clinical Excellence recently published their guidance – ‘Intrapartum care: care of healthy women and their babies during delivery’  which has created some divided views amongst experts

The need to improve patient safety in this area is of paramount importance. As well as devastating emotional consequences for those who encounter adverse care as a result of inappropriate intrapartum fetal monitoring, the financial implications are also profound. The NHS in England paid out £3.1 billion (49% of the value of all claims) for negligence linked to maternity care in the past decade, mainly for cerebral palsy and errors in the interpretation of CTGs (2). Sholapurkar has created an excellent resource which comprehensively documents an overview of intrapartum fetal monitoring, as well as its inherent controversies and pitfalls. (LINK – article)



  1. Intrapartum Fetal Monitoring. Patient.co.uk. http://www.patient.co.uk/doctor/intrapartum-fetal-monitoring
    Accessed on March 15, 2015
  2. Zosia K. News. NHS in England paid out £3.1bn in compensation claims linked to maternity care in past decade. BMJ.  2012; 345: e7290.

All resources on CTG Interpretation