Here is the design of a clinical trial:

Official Title: RMOS Study : Impact of Manual Rotation of Occiput Posterior Position on Operative Delivery Rate

Included conditions:
- Fetal Manual Rotation

Study Armgroups:
- {'label': 'prophylactic manual rotation', 'type': 'EXPERIMENTAL', 'description': 'Only obstetricians will participate in the study. Manual rotation is performed at full dilatation.The technique employed will be at the discretion of the operator performing the procedure :\n\n* Tarnier and Chantreuil technique\n* or SOGC technique', 'interventionNames': ['Other: prophylactic manual rotation']}
- {'label': 'expectative management', 'type': 'NO_INTERVENTION', 'description': 'Expectative management . No manual rotation'}

Interventions:
- {'type': 'OTHER', 'name': 'prophylactic manual rotation', 'armGroupLabels': ['prophylactic manual rotation']}

Primary Outcomes:
- {'measure': 'Percentage of spontaneous vaginal delivery', 'timeFrame': 'At the time of delivery'}

Please estimate the sample size based on the assumption: 
power of 90%, alpha risk of 5%, 10% of patients lost to follow-up
Sample size
        According to the hypothesis of Le Ray et al.âs study in 2013, 214 patients are required to show a 20% increase in the percentage of spontaneous vaginal delivery (60% without manual rotation vs 80% with manual rotation) with a power of 90% and an alpha risk of 5% (107 per group). We plan to include 238 patients in total to take into account the 10% of patients lost to follow-up.