[Analysis of labor progression characteristics of 1 089 nulliparas managed by the new partogram].

Objective: To analyze labor progression characteristics among nulliparas and provide reference to labor progress management. Methods: A retrospective study was conducted on 1 089 women who went for vaginal delivery at the First Affiliated Hospital, Sun Yet-San University from January 1st, 2015 to May 31th, 2016. The duration of cervical dilation from 1.0 cm to the next and the process of initial cervical dilation (2.0 cm or 3.0 cm) to full cervical dilation of nulliparas were analyzed. Results: The cervical dilation speed was accelerating with the progress of labor. The rate of cervical dilation changed fastest between 5.0-6.0 cm dilation, which was more than 3.0 cm/hour. With regard to labor curves, at admission of 2.0 cm cervical dilation, it rose dramatically from 5.0 cm dilation. At admission of 3.0 cm dilation, it presented approximately linear rising before 5.5 cm dilation, then became steeper. Conclusions: The cervical dilation speed is fast. Both labor curves of initial cervical dilation (2.0 cm or 3.0 cm) to full cervical dilation show obvious acceleration stage with steep slope.