title: Better perineal outcomes in sitting birthing position cannot be explained by changing from upright to supine position for performing an episiotomy.
abstract: BACKGROUND
  women who give birth in supine position are more likely to have an episiotomy than women who give birth in sitting position. A confounding effect may be that women in upright positions in second stage of labour are asked to lie down if a professional needs to perform an episiotomy. This prospective cohort study aimed to determine whether this factor can explain the lower rate of episiotomy in sitting compared to supine position.
  
  
  METHODS
  data from 1196 women who had a spontaneous, vaginal birth were analysed. Positions during second stage and at birth were carefully recorded. Three groups of birthing positions were compared in multivariable analyses: 1) horizontal during second stage and supine at birth (horizontal/supine), 2) horizontal and upright during second stage and supine at birth (various/supine), 3) sitting at birth regardless of the position in second stage. Logistic regression analysis was used to adjust for known risk factors for perineal damage.
  
  
  RESULTS
  women in sitting position at birth compared to those in the horizontal/supine group had a lower episiotomy rate (adjusted OR 0.28;95%-CI 0.14-0.56) and a non-significant higher intact perineum rate (adjusted OR 1.40, 95% CI 0.96-2.04). Women in the various/supine group compared to the horizontal/supine group had a similar episiotomy rate (adjusted OR 1.12;95%-CI 0.69-1.83).
  
  
  CONCLUSIONS
  we did not confirm our hypothesis that more women in supine compared to sitting position have an episiotomy because women in upright position are asked to lie down if an episiotomy is necessary.
authors.affiliation: Midwifery Science, AVAG and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands; Academic Medical Center, University of Amsterdam, Department of Obstetrics and Gynaecology, Amsterdam, The Netherlands.
authors.forename: Willemijn D B
authors.initials: WDB
authors.lastname: Warmink-Perdijk
authors.affiliation: Academic Medical Center, University of Amsterdam, Department of Obstetrics and Gynaecology, Amsterdam, The Netherlands; University Medical Center Groningen, Department of General Practice, A. Deusinglaan 1, 9713 CX Groningen, The Netherlands; Sanquin Research, Department of Experimental Immunohematology, The Netherlands. Electronic address: j.m.koelewijn@umcg.nl.
authors.forename: Joke M
authors.initials: JM
authors.lastname: Koelewijn
authors.affiliation: Midwifery Science, AVAG and the EMGO Institute for Health and Care Research, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Ank
authors.initials: A
authors.lastname: de Jonge
authors.affiliation: University Medical Center Groningen, Department of Obstetrics and Gynaecology, Groningen, The Netherlands.
authors.forename: Mariet Th
authors.initials: MT
authors.lastname: van Diem
authors.affiliation: University Medical Center St Radboud, Department of General Practice, Women Studies Medicine, Nijmegen, The Netherlands.
authors.forename: Antoine L M
authors.initials: ALM
authors.lastname: Lagro-Janssen
mesh_terms: D000328:Adult; D015331:Cohort Studies; D036861:Delivery, Obstetric / Q000379:methods*; D004841:Episiotomy / Q000009:adverse effects / Q000451:nursing / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007748:Labor Stage, Second; D008880:Midwifery; D009426:Netherlands; D056888:Patient Positioning; D010502:Perineum / Q000293:injuries* / Q000601:surgery; D011247:Pregnancy; D011446:Prospective Studies
keywords: Birthing positions; Episiotomy; Perineal damage; Perineal tear