A significant proportion of the reviews identified that healthcare professionals either did not recognise a pathological CTG or did not act upon a pathological CTG even when it was recognised.
A mother was admitted in early labour with severe hypertension. Continuous CTG was commenced 1 hour after admission as the initial focus was on stabilising the mother’s blood pressure. The CTG was not formally assessed using a recognised classification system for over 2 hours. Eventually, the CTG was classed as suspicious and the consultant was asked to review. The lack of reactivity was attributed to the antihypertensive therapy, and the plan was to continue with CTG and repeat vaginal examination 4 hours later.
At the next vaginal examination, the cervix was found to be 3 cm dilated; artificial rupture of the membranes was performed with thick meconium draining. The plan was to initiate ST Analysis (STAN) monitoring. However, the fetal scalp electrode could not pick up the fetal heart; a second clip was obtained and, despite good application, no fetal heart rate was recording. The consultant obstetrician was contacted to locate the fetal heart rate with transabdominal ultrasound, by which time there was a fetal bradycardia.
Immediate caesarean section was performed under general anaesthesia, but despite extensive resuscitation efforts the baby did not survive. A retroplacental clot was found on delivering the placenta.
This scenario illustrates a CTG that was pathological yet not acted upon as it was perceived to be caused by the antihypertensive therapy. The risk factors for abruption were not considered. The discovery of thick meconium on the rupture of membranes should have been added into the picture when considering the management of this baby.
The Each Baby Counts reviewers highlighted the repeated missed opportunities to identify earlier a suspicious or pathological CTG. In some babies, there was a lack of documented formal assessment and categorisation of the CTG.
A low-risk first-time mother attended her local birthing unit in labour. In the second stage, a deceleration was heard and so she was transferred to the delivery suite and continuous CTG was commenced. The CTG was abnormal, but it was interpreted incorrectly as having accelerations with contractions. Eventually, the CTG was identified as abnormal by the senior midwife (shift coordinator), who alerted the obstetric registrar. An instrumental delivery was performed immediately. The baby was pale and floppy on delivery and underwent active therapeutic cooling with a diagnosis of grade II HIE.
Interpretation of a CTG can be subjective. When acting alone, maternity providers have limited safeguards against getting this interpretation wrong.
Things you can do
Formal recording of the CTG assessment (e.g. stickers in the notes) should be undertaken as it has been shown to reduce the incidence of babies born with an Apgar score of less than 7.[i]
A buddy system and a ‘fresh eyes’ approach to CTG interpretation should be used in all units interpreting continuous CTG as there is evidence this may reduce errors in CTG interpretation.[ii]
[i] Draycott TJ, Sibanda T, Owen L, Akande V, Winter C, Reading S, et al. Does training in obstetric emergencies improve neonatal outcome? BJOG 2006;113(2):177–82.
[ii] Fitzpatrick T, Holt LA. A ‘buddy’ approach to CTG. Midwives 2008;11(5):40–1.