L-J van Bogaert1. 1. Department of Obstetrics and Gynaecology, MEDUNSA Satellite Campus, Philadelphia Hospital, Dennilton, South Africa. ljfvanbo@lantic.net
Abstract
OBJECTIVE: To investigate the distribution of the rate of cervical dilatation of primigravid labour and its deviation from the standard partogram. DESIGN: Retrospective observational study. SETTING: South African district hospital serving an indigent rural population. POPULATION: Expectant management of labour of healthy nulliparous women in active labour, at term, with a singleton pregnancy and cephalic presentation. METHODS: Audit of 1,595 partograms of spontaneous primigravid labour. The standard partogram's alert line was replaced by a customised alert line based on the lowest 10th centile of the rate of cervical dilatation of the study population and an alert line representing the 10% slowest labours. The action line was placed parallel and 4 h to the right of the alert lines. MAIN OUTCOME MEASURE: The distribution of labours left to and on the respective alert lines, and right to the action lines. RESULTS: The lowest 90th centile of the customised alert line yielded a rate of cervical dilatation of 0.860 cm/h. Three quarters of labours evolved left to the revised alert line as opposed to 56.1% left of the standard alert line [Odds ratio (OR) 0.49, 95% confidence interval (CI) 0.42-0.56]. The mean rate of cervical dilatation of the 10% slowest labours was 0.535 +/- 0.076 cm/h (P < 0.0001), and 95.7% of labours evolved left to the corresponding alert line (OR 8.40, 95% CI 6.44-11.0). CONCLUSION: The alert line representing the mean of the 10% slowest labours leads to an unrealistic distribution of labour on the partogram. A revised alert line based on the lowest 10th centile of the local population is more representative and should perhaps be used in the management of labour.
OBJECTIVE: To investigate the distribution of the rate of cervical dilatation of primigravid labour and its deviation from the standard partogram. DESIGN: Retrospective observational study. SETTING: South African district hospital serving an indigent rural population. POPULATION: Expectant management of labour of healthy nulliparous women in active labour, at term, with a singleton pregnancy and cephalic presentation. METHODS: Audit of 1,595 partograms of spontaneous primigravid labour. The standard partogram's alert line was replaced by a customised alert line based on the lowest 10th centile of the rate of cervical dilatation of the study population and an alert line representing the 10% slowest labours. The action line was placed parallel and 4 h to the right of the alert lines. MAIN OUTCOME MEASURE: The distribution of labours left to and on the respective alert lines, and right to the action lines. RESULTS: The lowest 90th centile of the customised alert line yielded a rate of cervical dilatation of 0.860 cm/h. Three quarters of labours evolved left to the revised alert line as opposed to 56.1% left of the standard alert line [Odds ratio (OR) 0.49, 95% confidence interval (CI) 0.42-0.56]. The mean rate of cervical dilatation of the 10% slowest labours was 0.535 +/- 0.076 cm/h (P < 0.0001), and 95.7% of labours evolved left to the corresponding alert line (OR 8.40, 95% CI 6.44-11.0). CONCLUSION: The alert line representing the mean of the 10% slowest labours leads to an unrealistic distribution of labour on the partogram. A revised alert line based on the lowest 10th centile of the local population is more representative and should perhaps be used in the management of labour.