Admission Cardiotocography Essay
This essay will critically evaluate both the evidence available and current midwifery practice. I will also refer to how this can affect maternal choice. The rationale for me choosing the subject of admission cardiotocography (CTG) is that during my delivery placement I witnessed on many occasions, midwives having to make decisions regarding the monitoring of the fetal heart during labour.
By the early 19th century, it was recognised that the fetal heart rate (FHR) altered in response to internal and external stresses, thus paving the way for the assessment of fetal well-being and ultimately for the development of fetal medicine (Sureau 1996). Since then, electronic fetal monitoring (EFM), which involves simultaneous recording of the FHR and uterine contractions to a print out known as cardiotocograph (CTG), has become the widely used technique for assessing fetal well-being during labour (Henson 1993).
Intermittent auscultation involves listening to the fetal heart at predetermined intervals using either a Pinard stethoscope or a hand-held Doppler ultrasound device (Devane et al 2005). A randomised controlled trial of cardiotocography versus Doppler auscultation of fetal heart at admission in labour in low risk obstetric population carried out by The Department of Obstetrics and Gynaecology, Ninewells Hospital and Medical School, Dundee, discovered that compared with Doppler auscultation of the fetal heart, admission CTG does not benefit neonatal outcome in low risk women, this was assessed by metabolic acidosis at delivery.
Furthermore, it concluded, its use resulted in increased obstetric intervention, including operative delivery. Thacker et al (2001) gathered evidence from studies which also suggested that continuous EFM resulted in a counter-intuitive reduction in neonatal seizures but an increase in caesarean section and operative vaginal delivery rates. However, current evidence suggests that neonatal convulsions alone are a poor marker for injury associated with intrapartum hypoxia (Royal College of Obstetricians and Gynaecologists) (RCOG 2001).
The National Institute of Clinical Excellence (NICE) guideline on CTG monitoring in labour (NICE 2001) recommends intermittent monitoring for low-risk labours and discourages the use of admission CTG. The guideline sets out risk factors that would classify a labour as high risk, for which it recommends continuous CTG monitoring. CTG monitoring was originally introduced with the aim of reducing perinatal mortality and cerebral palsy (Walsh 2003).
Women who are deemed high risk are assessed as having the following maternal problems; previous caesarean section, pre-eclampsia, post-term pregnancy (>42 weeks), prolonged rupture of membranes (>24hrs), induced labour, diabetes, antepartum haemorrhage, other maternal medical disease. Fetal problems include fetal growth restriction, prematurity, oligohydramnios, abnormal Doppler artery velocimetry, multiple pregnancies, meconium-stained liquor or breech presentation.
These problems are categorised by the NICE Guidelines (2001) where they state that midwives should offer and recommend continuous EFM. NICE (2001) also state that Intrapartum risk factors requiring continuous CTG are Oxytocin augmentation and epidural analgesia, however, Advanced Life Support in Obstetrics (ALSO) (Ailsworth et al 2000) states that continuous CTG is not required with mobile or continuous infusions, though it does advise a CTG when the initial bolus or top-ups are given.
Vaginal bleeding in labour, maternal pyrexia and fresh meconium-stained liquor also warrant a recommendation for continuous EFM. Following an audit undertaken by the Princess Alexandra Hospital NHS Trust in Harlow, Essex it found that some of the midwives performed unnecessary CTG’s for no other reason than they deemed it their routine practice. This audit was carried out to establish how midwives monitor the fetal heart during labour and to compare this with the recommendations set out in the NICE guideline on cardiotocograph (2001).
Generally, the midwives in the unit were shown to have good compliance with the NICE guideline, except in the case of admission CTG’s, where it was apparent that just under half those classified as low risk were found to have had an admission CTG (Harvey 2004). However, others were found to be not so straightforward. When a low risk mother presents to the labour ward in early or pre-labour, following spontaneous rupture of membranes (SROM), asking for reassurance of their baby’s well-being, the admission CTG may be a hard habit to break.
Reduced fetal movements may indicate fetal hypoxia and would seem to be a prudent reason for an admission CTG (Verralls 1993). Within my trust it has been apparent that the midwives are compliant to the NICE Guidelines (2001) and with the trust policies (RWST ? ). NICE Guidelines (2001) also recommend that intermittent auscultation occurs every 15 minutes in the first stage every 5minutes in the second stage and after every contraction for a period of one minute during the active stage of labour which is also recognised by the RCOG (2001).
It also emulates the importance of infection control when looking at EFM. The monitors are thoroughly cleaned after use to prevent cross infection, and the straps are never reused due to contamination of amniotic fluid and blood products, this is in keeping with the Nursing and Midwifery Council (NMC 2006) standard precautions to reduce the risk of infection, along with the Department of Health’s (2006) guidelines to reduce healthcare-associated infections which has recently had much media coverage relating to poor hygiene and increased hospital-acquired infections.
Classification of normal, suspicious and pathological CTG’s, along with fetal heart-rate categorisation is also defined. Difficulties in interpreting CTG’s were found to be a concern following research by The Confidential Enquiry into Stillbirths and Neonatal Deaths in Infancy (1997) into possible adjuncts to EFM (Neilson 2003). Despite its limitations, the continued use of EFM is driven by a desire to reduce intrapartum-related neurological damage and deaths to babies. However, serious difficulties have been highlighted with intrapartum EFM and the interpretation of CTG tracings.
Inconsistencies in inter- and intra-observer agreement in the visual interpretation and classification of CTG tracings is a well documented problem (Ayres-de-Campos et al 1999; Devane and Lalor 2005), and one that has serious implications for clinical decision making in intrapartum management (Devane and Lalor 2005). The Fourth Annual Confidential Enquiry into Stillbirths and Deaths in Infancy (CESDI) report, which provides an annual overview of the numbers and causes of stillbirth and infant death in England, Wales and Northern Ireland, identified 873 intrapartum deaths of babies weighing over 1. 5kg in the UK in 1995.
Sub-optimal care was identified in 80% of cases in which alternative management ‘might’ or ‘would reasonably be expected to’ have made a difference to the outcome (Maternal and Child Health Research Consortium 1997). The most common avoidable errors reported included failures in the use and interpretation of CTG tracings, failure to take appropriate action when the FHR was identified as abnormal, or both. The most common criticism in relation to CTG interpretation was the ‘apparent acceptance’ of a suspicious or abnormal tracing without any change in management (Maternal and Child Health Research Consortium 1997).
The report identifies poor education as the primary cause of failure to use EFM when clinically indicated, mis-recognition and misinterpretation of abnormal FHR patterns and of inappropriate action after abnormal FHR pattern recognition. The fifth and sixth CESDI annual reports continued to highlight problems surrounding the use and interpretation of CTG’s; they repeatedly recommended the need for adequate education (Maternal and Child Health Research Consortium 2000).
Although in-service fetal monitoring education programmes have been implemented in many institutions to varying degrees, few studies have evaluated the effect of such education on fetal monitoring knowledge and CTG interpretation skills. Litigation is becoming another major issue. Despite the limitations of the current recommendations of intermittent auscultation for fetal monitoring in an uncomplicated pregnancy, EFM has become a normal part of intrapartum care, due, in part to the constant fear of litigation (Symon 1998a) and the false reassurance offered by having a continuous record of FHR.
However, the use of EFM may not benefit mothers or their babies (Nelson 1999), and may as Walsh (1998) suggests, further increase litigation as a result of additional interventions that are based not on evidence but rather on the inappropriate use of technology. Indeed, the CTG tracing is widely used in cases of alleged negligence in maternity care (Maternity Defence Union 1998).