Labour Outcomes With Partograph Action Line Placement at 2 Hour Versus 4 Hours: A Randomised Controlled Trail

Materials and methods

This prospective, randomised controlled study was conducted from April 2008 to April 2013. The labour ward staff had very good knowledge of how to use the partograph, and partographs were routinely supplied in the labour ward. The department had a management protocol for the use of the partograph for labour supervision of all parturients in labour. In addition, an audited review of how labour was managed in all parturients occurred every morning on all workdays to assess compliance with the management protocol, which ensured the continuous instruction of all staff in partograph use for labour supervision.

At the time of admission, the study participants were nulliparous, between 37 and 42 weeks gestation, in the spontaneous active phase of labour with intact fetal membranes and had singleton, cephalic-presenting fetuses. The exclusion criteria were prior antepartum haemorrhage, medical disorders in pregnancy and poor fetal growth in pregnancy. All the women who fulfilled the inclusion criteria during the antenatal period at approximately 34-36 weeks were selected, participated in an informative discussion about the study and signed a written consent. The study was approved by the UBTH research and ethics committee after a review of the study protocol and informed consent details. However, final inclusion in the study was limited to previously selected women who arrived at the labour ward at term in spontaneous active-phase labour with intact fetal membranes and still had no exclusion criteria. Upon presenting at the labour ward and being confirmed to be in active labour, the consenting women were randomised to either of two study arms: labour supervision with composite partograph action line location at 2 hours or 4 hours from the alert line by the physician but blinded to the participants. Allocation to the study arms was performed using consecutively numbered, sealed, opaque envelopes with a randomised sequence using a computer random number generator by a statistician not involved with care. A sample size determination for a 2-hour versus a 4-hour oxytocin augmentation of labour with a type 1 error (alpha) of 10% and a type II error (beta) of 20% together with a power of 80% and a level of significance of 0.05 was performed on the basis of a previous study on the effects of different partograph action lines on birth outcomes. Recruitment into each arm of the study was calculated to require 320 participants. The enrolment of women in the study was continued until a sample size of 320 was achieved in each study group, the 2-hour or 4-hour action line. There were therefore no exclusions.

Data and statistical analysis

Collected data were checked for completeness and analysed using SPSS version 17 (SPSS Inc., 233 South Wackor Drive, Chicago, Illinois 60606-6412, USA). Bivariate analyses were performed using a chi-square test for differences in proportion between the 2-hour and 4-hour lines for categorical variables, and odds ratios (ORs) and the respective confidence intervals were calculated. Continuous variables were compared using unpaired t-tests. A p-value of <0.05 was considered indicative of statistical significance.