Background
Planned caesarean section (CS) is poorly understood as studies reporting CS outcomes often combine results for emergency and planned CS or compare outcomes with actual vaginal births only. This represents a substantial gap in knowledge as the alternative to planned CS is to plan a vaginal birth. As emergency CS is usually an outcome of planning vaginal birth, it is critical that the outcome of planned and emergency CS are analysed separately. Given that CS rate is rising progressively with reported rates of 24.5% in Western Europe and 32% in North America, there is a need for high quality evidence comparing planned CS to planned VD 1-4.
There is no consensus among patients, healthcare professionals and researchers regarding the outcome measures that should be collected and reported in studies assessing planned mode of birth. In absence of a standardised approach, researchers can only make arbitrary decisions when choosing among several important outcomes 5. Furthermore, reporting bias can occur if the outcome is selected retrospectively based on statistical significance of results6. In order for future studies to be comparable and for results to be usefully combined, it is crucial for reporting of outcomes to be consistent 7.
Core outcome sets capture the key outcomes based on what key stakeholders (clinicians, patients, their partners, researchers, service developers, funding organisations) consider important in the management or prevention of a condition 8, 9. Ideally, the primary outcome and other outcomes of a trial will be selected from a core outcome set if available, but researchers may continue to explore other outcomes and are not restricted to the outcomes in the core outcome set 9.The RCOG and Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) has formed the Core Outcomes in Women’s and Newborn’s Health (CROWN) initiative, which is supported by 80 journals, to tackle unwarranted variation in outcome reporting by encouraging the publication of studies reporting outcomes from a core outcome set where available 10, 11.
For a meaningful core outcome set for planned mode of birth to be developed, evaluation of reported outcomes and outcome measures across published studies is required 12. The aim of the present study was to identify and organise the outcomes and outcome measures reported in prospective studies investigating planned mode of birth.