Study information


(caesarean Section IMPLEmentation study)

Best timing of a caesarean section in non-progressing labour

A caesarean section performed without a clear indication results in additional morbidity and costs without improvement of outcome. The group of women delivering their first baby is the largest contributor to the caesarean section rate (46% of all caesarean sections in the Netherlands, 13.000 annually). In about 11% of all deliveries in secondary care, women are diagnosed with non-progressing labour, resulting in a caesarean section in 45% (SIMPLE I). This makes non-progressing labour one of the most important indications for a caesarean section. Although in the Netherlands about 6400 caesarean sections are annually performed based on non-progressing labour, the actual moment of diagnosis and timing of the caesarean section in this group is still unclear. The second largest group contributing to the caesarean section rate are women with a previous caesarean section. Reducing the number of caesarean sections in the first pregnancy reduces the number in the following one by at least 50%.

Primary Objective:
In women with non-progressing labour we want to assess the safety of waiting until the SIMPLE partogram is crossed compared to performing a caesarean section directly after the Friedman action line is crossed.

Study design
Multicenter randomized controlled trial

Study population
Term nulliparous women with an intention to a vaginal delivery and a singleton pregnancy with a child in cephalic presentation.

Inclusion criteria:

  • Nulliparous
  • Singleton pregnancy
  • Cephalic presentation
  • ≥ 37 weeks of pregnancy
  • ≥ 4 cm dilatation
  • Non-progressing labour (passing the Friedman partogram action line)
  • Pain considered manageable for continuation of delivery

Exclusion criteria:

  • < 18 years of age
  • Unable to read or understand informed consent
  • Fetus with relevant congenital malformation that can influence the delivery mode OR have a higher risk for NICU admittance
  • Indication for a caesarean section due to fetal distress

When after regular interventions (rupture of membranes, adequate pain medication, oxytocin augmentation, empty bladder) the Friedman partogram action line is crossed, randomisation occurs between performing a caesarean section (control group) and waiting until the Simple partogram action line is crossed (intervention group).

Outcome measures
The main study endpoint will be a composite outcome of mortality and severe morbidity (defined as maternal intensive care admittance, neonatal intensive care admittance, arterial pH ≤7.10 and 5 minute Apgar score <7).

Secondary study endpoints will be: delivery mode, shoulder dystocia, anal sphincter lesions, blood loss, need for blood transfusion, maternal infection, neonatal infection, duration of admission to the hospital.

Other study parameters will be cost effectiveness, budget impact, patient preference and patient satisfaction.

Power/data analysis
This trial will be a non-inferiority trial. In order to be able to show non-inferiority with a non-inferiority margin (delta) of 2%, assuming a baseline risk of 2% for each intervention, a power of 90% and an alpha of 2.5%, we need 1031 women in each group. Taking into account an attrition rate of 5% (i.e. 95% complete records), and an extra-required sample size of 10% in view of power loss in multilevel analysis, 1194 women per group should be recruited.

Economic evaluation
A trial based economic evaluation will be performed according to published guidelines[11], based on empirical data obtained in the cluster RCT. As most of the events take place during the period of maternity leave we do not expect productivity costs to differ between strategies. The economic evaluation will therefore be performed from the health care perspective, including only health care costs. The time horizon of the economic evaluation will be from inclusion up to 6 months following delivery. The intervention offered in this study may affect maternal morbidity. Therefore a cost-utility analysis will be performed with the number of quality adjusted life years (QALYs) as the primary outcome measure. Additionally, the costs per prevented composite adverse outcome in the infant will be calculated. Uncertainty in cost-effectiveness will be addressed by means of standard sensitivity analyses, bootstrap analysis and cost-effectiveness acceptability curves. The economic evaluation will be performed in a subgroup of 2x150 women with non-progressing labour.

Time schedule
36 months

Dr. H.C.J. Scheeper, gynaecologist, Maastricht University Medical Centre+

Health Technology Assessment
Prof. Dr. C.D. Dirksen, clinical epidemiology and medical technology assessment (KEMTA), Maastricht University Medical Centre+


Dr. L. Smits, methodologist, Maastricht University Medical Centre+
Dr. S. Zwolsman,  Trialbureau NVOG Consortium 2.0

ZonMw 843002621

Contact (researcher)

Drs. F.K.L. Tournois

Maastricht University Medical Centre+

P. Debyelaan 28

6229 HX Maastricht

P: 043 3874768