Incidence of Obstetric Anal Sphincter Injuries by 60 Degrees for the Incision Angle of Mediolateral Episiotomy before Delivery

Abstract

Objective: To evaluate the incidence of obstetric anal sphincter injuries (OASI)by 60 degrees for the incision angle of mediolateral episiotomy before delivery.

Materials and Methods: Descriptive study of 70 primiparous women at 37-42 weeks of gestation deliveried between October 2011 and May 2012 in the labor room, Taksin Hospital. All women were incised with 60 degrees of mediolateral episiotomy. The main outcome was obstetric anal sphincter injuries. And the angles formed by the suture lines with the midline were measured.

Results: Of 70 primiparous women recruited into the present study, the mean gestational age was 38.67± 1.05 weeks, the mean birthweight was 3011 ± 334 grams.  The mean suture angle of episiotomy was 42⁰ ± 4.8⁰ with change of angle 18⁰ ± 4.8⁰.  The incidence of OASI was 1.4 % (1 of 70).

Conclusion: The incision angle 60 degrees of mediolateral episiotomy before delivery is adequate angle to prevent obstetric anal sphincter injuries.