Perineal deformation during forceps, vacuum and OdonAssist™ assisted vaginal deliveries: A simulation study based on advanced image processing.

Objectives: The aim of this study was to analyse influence of the fetal head position and the type of instrument used (forceps, vacuum, OdonAssist™) on perineal deformation, during simulated vaginal deliveries monitored by stereophotogrammetry.

Methods: An exploratory study was conducted using mannequins simulating vaginal births. Fifty simulated deliveries were performed with different fetal head positions and instruments: Pajot's forceps, Kiwi-vacuum, and OdonAssist™.