ObjectiveTo investigate the characteristics of carve of labour duration in the first labour stage by analyzing 1 913 cases of nulliparous women.

MethodsA total of 1 913 cases of nulliparous women with singleton, full-term and cephalic presentation were selected and divided into natural parturient group (n=1 523) and oxytocin group (n=390).The age, birth gestational age, body mass, height, neonatal birth mass, dilatation and duration of uterine cervix, the time required for uterine cervix dilatation per 1 cm in two groups were collected and retrospectively analyzed.

ResultsThe birth gestational age in natural parturient group and oxytocin group was (39.6±0.9) weeks and (39.9±1.1) weeks, respectively, the difference of which was statistically significant (P < 0.05).There was no significant difference in age, body mass, height, body mass index and neonatal birth mass between two groups (P>0.05).The carve of labour duration of nulliparous women showed a slowly rising trend in the first stage of labour, and the carve of labour duration presented ascending trend after the cervix opened 5 cm in two groups.The duration of uterine opening at 3-4, 4-5, 5-6 and 7-8 cm in natural parturient group was longer than that in oxytocin group (P < 0.05 to P < 0.01), and there was no significant difference in the duration of uterine opening at 6-7, 8-9 and 9-10 cm between two groups (P>0.05).There was no significant difference in the starting point distribution of active phase between two groups (P>0.05).

ConclusionsBoth Friedman labour curve and the new obstetrics labor standard can not exactly describe the characteristics of labor in China.More maternal labor data in China should be further collected, and a suitable curve of labor duration should be drawn to guide the labor process.