Risk factors associated with severe posterior perineal trauma

Abstract

Introduction: There has been an apparent increase in severe posterior perineal trauma (third or fourth drgree perineal lacerations) at San Bartolome Mother and Child Hospital, whose immediate and mediate complications make it imperative to identify associated risk factors. Objective: To identify risk factors associated with severe posterior perineal trauma. design: Descriptive retrospective transversal study. Setting: San Bartolome Mother and Child Hospital, Lima. Participants: patients with the diagnosis of posterior perineal trauma during vaginal delivery. Interventions: We reviewed 146 clinical histories af all patients with the diagnosis of severe posterior perineal trauma following vaginal delivery, from january 2000 throuhg december 2004. statistical analysis used SPSS version 11,0 with central tedency index (middle, median and mode), dispersion and correlation tendencies. main outcome measures: Severe posterior perineal lacerations, episiotomy type, instrumental delivery, parity, newborn weigth. Results: During the study period 25044 vaginal deliveries were attended, 146 presenting severe posterio perineal lacerations, with annual incidence 0,58%; 69,2% (101 cases) had mediolateral episiotomy, 5,5% (8 cases) median episiotomy and 25,3% (37 cases) had no episiotomy. severe posterior perineal lacerations accurred most frequently in vaginal deliveries (89,7%), with forceps applications (8,9%) and vaccum extractor application (1,4%). Cases of severe posterior perineal lacerations were more frequent in nuliparae (80,1%) than in nuliparae (19,9%). In 85,6 of cases of severe posterior perineal lacerations newborns weighed less than 4 kg and only in 14,4% weighed more than 4kg. Conclusions: Average annual incidence of severe posterior perineal trauma was 0,58% and prsentation was variable. Episiotomy use and nuliparity increased severe posterior perineal trauma risk. Forceps delivery and large fetus above 4 kg were not associated to trauma.