title: Site and incidence of birth canal lacerations from instrumental delivery with mediolateral episiotomy.
abstract: OBJECTIVE
  Instrument-assisted vaginal delivery is a significant risk factor for birth canal lacerations. Although many obstetricians recently are recommending restrictive rather than a routine episiotomy, reports have shown restrictive episiotomy to be associated with more extensive anterior birth canal trauma compared with routine episiotomy.
  
  
  METHODS
  We retrospectively reviewed 110 cases of forceps and vacuum deliveries and investigated the site of birth canal lacerations. Birth canal lacerations were divided into four sites according to direction-anterior, ipsilateral, contralateral, and posterior.
  
  
  RESULTS
  The frequency of lacerations were, from most to least, posterior (34%), lateral (21.7%), and anterior (1.9%). Moreover, among the lateral lacerations, they were more frequent in the contralateral side of episiotomy than the ipsilateral side (18.9% vs. 4.7%, p < 0.01).
  
  
  CONCLUSIONS
  Our results indicate that caution is also needed concerning not only the anterior site, but also the contralateral site of an episiotomy to prevent laceration in an instrument-assisted vaginal delivery.
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan.
authors.forename: Kenro
authors.initials: K
authors.lastname: Chikazawa
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Ushijima
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan. Electronic address: kenjirotakagi@me.com.
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Takagi
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan.
authors.forename: Eishin
authors.initials: E
authors.lastname: Nakamura
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan.
authors.forename: Koki
authors.initials: K
authors.lastname: Samejima
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Kadowaki
authors.affiliation: Saitama Medical Center, Jichi Medical University, Perinatal Center, Division of Maternal Fetal Medicine, Saitama, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Horiuchi
mesh_terms: D000328:Adult; D004841:Episiotomy / Q000009:adverse effects*; D005113:Extraction, Obstetrical / Q000009:adverse effects*; D005260:Female; D006801:Humans; D015994:Incidence; D022125:Lacerations / Q000453:epidemiology*; D010502:Perineum / Q000293:injuries*; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D014621:Vagina / Q000293:injuries*; D055815:Young Adult
keywords: episiotomy; forceps delivery; operative vaginal delivery; perineal laceration; vacuum delivery