Intrapartum cardiotocography: an exploratory analysis of interpretational variation

Our aim was to evaluate the intra- and inter-operator agreement in cardiotocography (CTG) traces analysis using the 2015 FIGO classification guidelines, and whether the educational background and the knowledge of anamnestic data can influence the interpretation of CTG traces. A retrospective interpretation of 73 intrapartum CTGs at time 0 (T0) for a first blind interpretation and at time 1 (T1) two months later with additional anamnestic pregnancy information was made by eight different operators (four obstetricians and four midwives with different years of work experience). The intra-observer agreement demonstrates that midwifes are more concordant than obstetricians with a mean of 77.05% versus a mean of 65.75%. There is moderate inter-observer agreement in classifying a CTG trace as ‘normal’; on the contrary, there is no consensus on the ‘suspect’ and ‘pathological’ classification category.IMPACT STATEMENTWhat is already known on this subject? Interpretation of intrapartum CTG is affected by significant subjective variables with relevant intra- and inter-observer lack of optimal agreement, especially in case of abnormal o pathologic findings. What do the results of this study add? Clinical data seem to play a role in interpretation of suspicious and pathological traces while they do not affect the rate of agreement for normal traces. Midwives tend to be less influenced by anamnestic data in visual CTG interpretation. Instead, obstetricians tend to be more focussed on clinical data and clinical setting that, as a consequence, tend to have great impact on CTG trace interpretation. What are the implications of these findings for clinical practice and/or further research? Cooperation among obstetricians and between obstetricians and midwives should be encouraged in order to optimise CTG reading and improve maternal and neonatal outcomes. Regarding the influence of clinical parameters in classification of intrapartum CTG traces, especially in case of abnormal CTG traces, it should be conceivable to improve medical skills in CTG blind interpretation and further investigate which clinical parameters are mainly related with an augmented risk of foetal asphyxia and adverse neonatal outcomes.