Thesis title: The Labour Progression Study (LaPS). Assessing labour progression using different guidelines: Maternal and neonatal outcomes.
Trial lecture title: Management of vaginal breech birth – history, indications for mode of delivery, and outcomes for mothers and babies.
The ordinary opponents are:
- First opponent: Associate Professor Anna Dencker, University of Gothenburg, Sweden
- Second opponent: Professor Magnus Westgren, Karolinska Institutet, Sweden
- Leader of the committee: Associate Professor Oliwia Witczak, OsloMet
The leader of the public defence is Associate Professor Anne Kaasen, OsloMet
The main supervisor is Associate Professor Stine Bernitz, OsloMet. The co-supervisors are Professor Ellen Blix, OsloMet, and Professor Pål Øian, UiT – The Arctic University of Norway.
Abstract
Partographs and guidelines are used to assess and monitor labour progression, and they aim to identify slow progress of labour and determine the appropriate management of labour.
There is no standardised definition of labour duration or onset of labour, nor is there a consensus to which guideline is best suited for clinical use for assessing labour progression.
Escalation in the global rates of labour interventions, particular caesarean sections and oxytocin augmentation, has strengthen the interests in understanding the labour progression.
Research suggests that some interventions, such as intrapartum caesarean sections (ICS) and oxytocin augmentation, might be performed too soon, according to the prevailing definitions of normal labour progress and labour dystocia.
This means that labours in women with slow progress might be misclassified as abnormal and thus increase the chance of unnecessary interventions.
The overall aim was to investigate in what way two different guidelines for assessing labour progress, the WHO partograph and Zhang’s guideline, affect maternal and neonatal outcomes related to delivery among nulliparous women with a singleton vertex infant and spontaneous onset of labour at term.
Aims
- To investigate the use of intrapartum caesarean sections.
- To investigate the use of oxytocin augmentation
- To investigate labour duration in different labour phases and stages.
We planned, initiated, and implemented the Labour Progression Study (LaPS) according to the signed protocol. The LaPS was a cluster randomised trial collecting data between December 2014 and January 2017.
The LaPs data is the basis of all analyses presented in the three papers included in this thesis. A total of 14 clusters were enrolled in the trial.
The obstetric units, acting as clusters, were randomly assigned (1:1) to the control group or to the intervention group. The randomisation was computer generated, stratified by the proportions of previous ICSs and the number of deliveries.
Women randomised to the control group, adhered to the WHO partograph and women randomised to the intervention group adhered to the Zhang’s guideline.
Trial participants
A total of 11 615 women were considered eligible to participate in the trial, and 7,277 (62.7 percent) women with signed consent were included in the analyses. The number of ICS were 271 (6.8 percent) in the Zhang group and 196 (5.9 percent) in the WHO group, and did not differ between the groups.
However, the ICS rates were reduced in both the Zhang and WHO group by 26.5 percent and 37.8 percent, respectively. Oxytocin augmentation was used in 1658 (41.7 percent) women in the Zhang group compared with 1561 (47.2 percent) women in the WHO group, with no statistical significant difference between the groups.
In the Zhang group 24.1 percent of the participants were augmented with oxytocin prior to 6 centimetres of cervical dilatation compared with 28.4 percent in the WHO group and 18.5 percent of the women in the Zhang group were augmented with oxytocin without being diagnosed with labor dystocia compared with 23.2 percent in the WHO group.
Median duration of labour
The adjusted median duration of labour was 7.0 hours in the Zhang group, compared with 6.2 hours in the WHO group; the median difference was 0.84 hours with 95 percent confidence interval [CI] (0.2–1.5).
The adjusted median duration of the first stage was 5.6 hours in the Zhang group compared with 4.9 hours in the WHO group; the median difference was 0.66 hours with 95 percent CI (0.1–1.2).
The corresponding adjusted median duration of the second stage was 88 and 77 minutes; the median difference was 0.18 hours with 95 percent CI (0.1–0.3).
There were no maternal or neonatal deaths identified during the study period.
No significant differences
In conclusion, the results did not demonstrate significant differences in ICS rates or proportion of oxytocin administration between women in the Zhang group compared with women in the WHO group.
However, women in the Zhang group were less likely to be augmented with oxytocin prior to six centimetres of cervical dilatation.
Furthermore, we found a longer overall duration of labour and duration of first and second stages for women adhering to Zhang’s guideline compared with the WHO partograph.
Thesis contribution
The findings from the LaPS represent important obstetric knowledge when adhering to two different guidelines for assessing labour progression and the results may influence clinical practice of today.
The thesis highlights the challenge if standard guidelines in maternity care should be normative and generates thoughts on whether individual variations should be taken into account when assessing labour progression.
The thesis contributes with robust information to the worldwide discussion on how to reduce unnecessary interventions.
