Study on the morphology of perineal body during delivery

Objective:To observe the morphology of perineal body, provide some consults for practicing episiotomy or perineorrhaphy.Methods: Range of extension, degree of elasticity and thickness were measured for 423 random primipara when they were during the head visible on vulval gapping.Results:Perineum was extended from 2~3 cm in normal condition to 5~10 cm during the head visible on vulval gapping. 77.07% primiara's perineum was extended to 6~7 cm.According to the change of perineal body in delivery, perineum were divided into three types: popular type, thick type and thin type.Conclusion: According to fetal weight and type of perineum, we should determine that we whether practice episiotomy or not during delivery..For popular type, we should defend perineum as far as possible, we can also select episiotomy. For thick type, we should usually select median episiotomy. For thin type, to prepare lateral episiotomy as early as possible.