title: Birthing postures and birth canal lacerations.
abstract: OBJECTIVE
  This study was performed to assess the differences in the birth canal lacerations following the lateral and fours posture deliveries compared with those following the supine posture deliveries.
  
  
  METHODS
  We examined the birth canal lacerations of our "low risk" pregnant women under the midwife-led delivery care at Japanese Red Cross Katsushika Maternity Hospital between April 2006 and March 2015.
  
  
  RESULTS
  There were 3826, 1754 and 719 women who delivered with supine, lateral and fours postures. The rate of no laceration in the women who delivered with lateral posture was significant lower than that in the women who delivered with supine posture (OR 0.630, 95% CI 0.56-0.71, p < 0.01); however, the incidence of perineal laceration in the women who delivered with lateral posture was significant lower than that in the women who delivered with supine posture (OR 0.856, 95% CI 0.76-0.90, p < 0.01). The incidence of perineal laceration of third- or fourth-degree in the women who delivered with fours posture was significant higher than that in the women who delivered with supine posture (OR 2.28, 95% CI 1.2-4.2, p < 0.01).
  
  
  CONCLUSIONS
  The current results may be to help for self-determination of birthing postures in prenatal women.
authors.affiliation: a Department of Obstetrics and Gynecology , Japanese Red Cross Katsushika Maternity Hospital , Tokyo , Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Suzuki
mesh_terms: D000328:Adult; D016550:Birthing Centers / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric / Q000009:adverse effects / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D022125:Lacerations / Q000453:epidemiology*; D008880:Midwifery; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D010502:Perineum / Q000293:injuries*; D011187:Posture; D011247:Pregnancy; D012307:Risk Factors
keywords: Birth canal laceration; Japan; birthing posture