Abstrakt
Perineal mapping is the complex analysis of the impact of anatomical conditions and interventions during the final phase of vaginal birth on risk of maternal perineal trauma. It includes tests on physical or computational models, experimental measurements on human tissues or clinical evaluation of different factors at the time of birth.
Experimental perineal mapping utilises data obtained from different sources such as stereophotogrammetry, virtual simulations, direct physical measurements and ultrasonography or other imaging techniques. Clinical perineal mapping involves data analysis based on the size of the fetal head, length/diameter of the genital hiatus, dimensions and elasticity of the perineal tissues or the co-operation of the parturient.
This allows for individualised selection of certain modifications from a set of obstetric interventions e.g. use of obstetric gel, type and timing of episiotomy, manual perineal protection, slowing of the passage of the fetal head, second stage perineal massage, local application of warm packs. These interventions are employed to decrease frictional forces, increase the diameter of the vaginal introitus, decrease the size of the passing object, disperse/decrease the perineal tension, increase the elasticity of the perineum and/or control the speed of the delivery of the fetus and to harmonize all complex processes with the maternal efforts.
With the use of perineal mapping, an international classification of episiotomies has been developed and the effectiveness of manual perineal protection has been evaluated based on biomechanical principles while considering a variety of its modifications. Other interventions are in line for future analysis.