Is it possible to detect malposition of the vertex at an early stage in labour? A case-control study.

OBJECTIVES

The aim of this study was to investigate if there are clinical signs which allow detection of malposition of the vertex on admission to the delivery unit, or when crossing the action line on the partogram.

STUDY

DESIGN

Case-control study from 2007 to 2010 conducted on the delivery unit of Nordland Hospital, Bodø. Labours with malposition of the vertex (n = 171) were compared with a group with normal vertex presentation (n = 165). The positive predictive value was estimated for each sign using Bayes' rule.

MAIN OUTCOME MEASURES: Magnitude of positive predictive value for each clinical sign.

RESULTS

The positive predictive values for malposition were 9% if the foetus were in a right position, 11% if the labour was induced, 5% if the foetus was above the ischial spines, 4% if the reason for admission was contractions and 6% if cervix was <3 cm.

CONCLUSION

The ability of clinical assessment to predict malposition, either on admission or when crossing the action line on the partogram, was poor. Diagnosing malposition of the vertex requires other methods with a higher predictive value.