Changing Trends in Rate of Cervical Dilation in First Stage of Labor: Prospective Longitudinal Study

Introduction: Knowledge of change in the duration of stages of labour would be an essential step to reduce the increasing rates of cesarean section reported worldwide. Objective: To study the rate of cervical dilation in the 1st stage of labour in spontaneous and induced labour and in primigravida and multigravida with singleton pregnancy. Methods: A prospective observational study conducted at a multispeciality hospital was carried out for a period of 3 years from Jan 2017 to Dec 2019. A total of 640 patients who were admitted with spontaneous and induced labour having singleton pregnancy with cephalic presentation and intact membranes after 34 weeks who delivered vaginally were included for analysis. Progression of labor in the 1st stage of labour was measured by the rate of cervical dilation as noted by serial per vaginal examination and findings were plotted in partograph. Result: The difference between mean rate of cervical dilation in the study group is statistically significant between 4 - 6 cm and 6 - 10 cm (P < 0.0001). When primigravida & multigravida patients were compared for the cervical dilation rate, statistically significant difference was seen between 4 - 6 cm but not in 6 - 10 cm. Average rate of cervical dilatation was 3.44 (Standard Deviation (SD) = 1.84) in spontaneous labor while average rate of cervical dilatation was 2.69 (SD = 1.18) in induced labor between 6 - 10 cm of cervical dilatation. Conclusion: The active phase of labour starts at 6 cm of cervical dilation in the majority of the patients. In multigravida, cervix dilates at faster rate before 6 cm. In induced labour cervix dilates at a slower rate than spontaneous labour after 6 cm dilation.