Aims and background:The length of labor and the rate of cervical dilatation differ between populations.This study was conducted in low-risk pregnancies in a tertiary care center to assess the average rate of cervical dilatation from the start of labor to 4-6 cm cervical dilatation and from 4 to 6 cm cervical dilatation until the completion of the first stage of labor.Materials and methods: From January 2021 to July 2022, 176 low-risk laboring patients participated in an observational study.We determined the time interval for each cervical dilatation and the time interval from one cervical dilatation to full dilatation of the cervix.For each centimeter of cervical dilatation, the rate of cervical dilatation was estimated.For nulliparas, we created a labor curve using a nonlinear regression model.Results: During the latent phase, the mean cervical dilatation was approximately 0.5 cm/hour, whereas in the active phase it was 2.8 cm/hour.With increased cervical dilatation and higher parity, labor progressed more quickly.In all three parous groups, the rate of cervical dilatation nearly doubled between 5 and 6 cm.Therefore, in our study, the active phase began at 5 cm.After 5 cm, the labor curve we created for nulliparas showed a smooth exponential pattern with a modest upward slope. Conclusion:The labor progression rates in our study population were similar to those of the American and Chinese populations and faster than those of the Japanese population, but slower than those of the Swedish population.Clinical significance: Labor progression rates vary across populations due to differences in obstetric practices and demographic characteristics.Hence, the incidence of cesarean sections can be reduced by creating customized labor curves based on population-based research on cervical dilatation rates.
SA et al. (Fri,) studied this question.