Comparison of effacement curve with dilatation curve for prediction of labor progression.

Aim: This study was conducted to evaluate the ability of the effacement curve to predict fetal descent by comparing it to dilatation in order to improve the accuracy of the current partogram.

Method: We conducted an observational study of women who were admitted for vaginal delivery at Mobini Hospital, Sabzevar, Iran in 2015. During labor, dilatation and effacement were plotted in different graphs and then their association with fetal descent was separately evaluated and compared. This assessment was performed in two groups: primipara and multipara.

Results: From 1750 individuals, 503 primiparous and 512 multiparous women were eligible for the study. An adjusted generalized estimating equations multivariable model showed both dilatation and effacement had a significant relationship with fetal descent either in primipara or multipara. In primipara, the prediction value of effacement equalled dilatation (β,eff 0.29, P < 0.001; β,dil 0.30, P < 0.001). In multipara, the prediction value of effacement was obviously higher than dilatation (β,eff 0.45, P < 0.001; β,dil 0.27, P < 0.001). The strength of effacement to predict labor in multipara was clearly greater than in primipara (β,eff 0.45 and β,eff 0.29, respectively). The strength of dilatation to predict labor in multipara was comparable to primipara (β,dil 0.27 and β,dil: 0.30, respectively).

Conclusions: Regarding the acceptable predictive value of effacement, we believe considering effacement, dilatation and station curves altogether can improve the power of the existing partogram for the assessment of labor progression and detection of failure to progress.