Mediolateral episiotomy and anal sphincter trauma

OBJECTIVE: A summary of recent knowledge of the correlation between mediolateral episiotomy and anal sphincter injury. DESIGN: Review. SETTING: Department of Gynaecology and Obstetrics, Charles University and University Hospital Pilsen. CONCLUSIONS: The methodology of most studies is not well managed. Four problematical points were identified: definition of the mediolateral episiotomy, practical execution of the mediolateral episiotomy, diagnostics of perineal trauma and classification of the perineal trauma. Mediolateral episiotomy is often deficiently defined. Definitions differ depending on individual textbooks or departments. The majority of studies gives no definition and no description of the practical execution of an episiotomy or describes it inadequately. To the current knowledge there is no international consensual definition, which is used universally. Until 2003, there was no study evaluating adequate implementation of the mediolateral episiotomy. It appears that most of executed mediolateral episiotomies are not truly mediolateral. The angle of inclination between 40-60 degrees was suggested. According to the latest study, the lower limit of the mediolateral episiotomy definition (40 degrees) appears to be insufficient. At the present time, the correlation between mediolateral episiotomy and perineal trauma cannot be precisely evaluated. Before analyzing the benefits and risks of mediolateral episiotomy, an international consensus must be found, that would establish an exact definition of mediolateral episiotomy.