Recognising Fetal Compromise in the Cardiograph during the Antenatal Period: Pearls and Pitfalls
Susana Pereira
Department of Fetal Medicine, Kingston Hospital NHS Foundation Trust, Galsworthy Road Kingston Upon Thames, Surrey KT2 7QB, UK.
Caron Ingram
Fetal Surveillance Midwife, Basildon University Hospital, Nethermayne, Basildon Essex, SS16 5NL, UK.
Neerja Gupta
Basildon University Hospital, Nethermayne, Basildon, Essex, SS16 5N, UK.
Mandeep Singh
Department of Feto-Maternal Medicine, Southend University Hospital NHS Foundation Trust, Prittlewell Chase, Westcliff-on-Sea, Southend-on-Sea, Westcliff-on-Sea, SS0 0RY, England.
Edwin Chandraharan
Global Academy of Medical Education and Training, Office 4, 219 Kensington High Street, Kensington, London, England.
*Author to whom correspondence should be addressed.
Abstract
There are several national and international guidelines to aid the interpretation of the cardiotocograph (CTG) trace during labour. These guidelines are based on assessing changes in the fetal heart rate (i.e. cardiograph) in response to mechanical and hypoxic stresses during labour secondary to ongoing frequency, duration and strength of uterine contractions (i.e. tocograph). However, during the antenatal period, uterine contractions are absent, and therefore, these intrapartum CTG guidelines cannot be used to reliably identify fetuses at risk of compromise. Computerised analysis of CTG using the Dawes-Redman Criteria could be used to detect fetal compromise. However, clinicians should be aware of the multiple pathways of fetal damage (i.e. inflammation, infection, intrauterine fetal stroke, chronic fetal anaemia, acute feto-maternal haemorrhage and fetal cardiac or neurological disorders) which can cause changes on the CTG trace which may not be recognised by using CTG guidelines.
Keywords: Antenatal cardiograph, computerised CTG, short term variability, sinusoidal pattern, Dawes-Redman Criteria, Chronic Hypoxia