عوامل مرتبط با پارگی درجه چهارم در زایمان واژینال

Background: To identify the risk factors of fourth-degree laceration during vaginal delivery. Methods: This is a retrospective, case control study. We reviewed 131802 records of vaginal deliveries within 14 years period from 1990 to 2004 in two obstetric center. Cases were 93 vaginal deliveries with fourth-degree laceration and 7 cases were delivered at home, control subjects were 200 vaginal deliveries without third- or fourth-degree lacerations and were identified with the use of random selection. We studied the effects of: maternal age, nationality, parity, gestational age, hour of delivery, birth attendants, episiotomy use and duration of second stage of labor, use of oxytocin, use of forceps or vaccum, Infant birth weight, presentation and postion of fetus, previous severe perineal injury, maternal medical illness and place of delivery. Results: We found 93 cases (%0.07) of documented fourth-degree laceration in 131802 deliveries Conclusion: This study identified several factors associated with fourth-degree laceration. Median episiotomy should be avoided. Nulliparity, fetal macrosomia and OP position are significant risk factors that require caution by birth attendants during delivery