Analysis of the obstetrician's posture and gestures during a simulated forceps delivery

Background: The objective of this study is to identify and qualify, by means of a three-dimensional kinematic analysis, the postures and gestures of obstetricians during a simulated forceps birth, and then to study the influence of the experience of the obstetricians on how the technique was adopted. Method Volunteer obstetricians with varying levels of experience and types of practice were included in this study. The beginners had performed less than 10 forceps deliveries in real conditions (excluding simulation), the intermediates between 10 and 100, and the experts more than 100. The posture and gestures of these obstetricians were recorded using an optoelectronic motion capture system during forceps birth simulated on a mannequin. Data were analysed between three phases of the foetal traction. These phases were defined by the passage of a virtual point associated with the forceps blade through two anatomical planes: the mid-pelvis and the inferior strait. Then, a consolidated ascending hierarchical classification was applied to these data in order to objectify the existence of groups of similar behaviours. Results Different postures were observed when crossing the first plane, including different traction techniques. Experts mainly positioned themselves in either a “chevalier servant” posture (going down on one knee) or a “squatting” posture before initiating traction. During traction, they made little movement until the deflection of the foetal head, that is, until they crossed the second plane. Many of the beginners stood up initially. The quantity of movement produced reduced with the level of expertise. Conclusion Experienced obstetricians favoured postures that enabled observation at the level of the maternal perineum, and techniques that reduced movement amplitude. The next aim was to relate these different techniques to the traction force generated. The results of these studies have the potential to contribute to the training of obstetricians in forceps delivery, and to improve the safety of women and newborns.