title: A prospective cohort study of the morbidity associated with operative vaginal deliveries performed by day and at night.
abstract: OBJECTIVE
  To evaluate maternal and neonatal outcomes associated with operative vaginal deliveries (OVDs) performed by day and at night.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Urban maternity unit in Ireland with off-site consultant staff at night.
  
  
  METHODS
  All nulliparous women requiring an OVD with a term singleton fetus in a cephalic presentation from February to November 2013.
  
  
  METHODS
  Delivery outcomes were compared for women who delivered by day (08:00-19:59) or at night (20:00-07:59).
  
  
  METHODS
  The main outcomes included postpartum haemorrhage (PPH), anal sphincter tear and neonatal unit admission. Procedural factors included operator grade, sequential use of instruments and caesarean section.
  
  
  RESULTS
  Of the 597 women who required an OVD, 296 (50%) delivered at night. Choice of instrument, place of delivery, sequential use of instruments and caesarean section did not differ significantly in relation to time of birth. Mid-grade operators performed less OVDs by day than at night, OR 0.60 (95% CI 0.43 to 0.83), and a consultant supervisor was more frequently present by day, OR 2.26 (95% CI 1.05 to 4.83). Shoulder dystocia occurred more commonly by day, OR 2.57 (95% CI 1.05 to 6.28). The incidence of PPH, anal sphincter tears, neonatal unit admission, fetal acidosis and neonatal trauma was similar by day and at night. The mean decision to delivery intervals were 12.0 and 12.6 min, respectively.
  
  
  CONCLUSIONS
  There was no evidence of an association between time of OVD and adverse perinatal outcomes despite off-site consultant obstetric support at night.
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Katherine
authors.initials: K
authors.lastname: Butler
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Ramphul
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Clare
authors.initials: C
authors.lastname: Dunney
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Maria
authors.initials: M
authors.lastname: Farren
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Aoife
authors.initials: A
authors.lastname: McSweeney
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Karen
authors.initials: K
authors.lastname: McNamara
authors.affiliation: Academic Department of Obstetrics & Gynaecology, Trinity College, University of Dublin, Coombe Women & Infants University Hospital, Cork, Dublin, Republic of Ireland.
authors.forename: Deirdre J
authors.initials: DJ
authors.lastname: Murphy
mesh_terms: D000328:Adult; D001003:Anal Canal / Q000293:injuries*; D001720:Birth Injuries / Q000453:epidemiology*; D015331:Cohort Studies; D004420:Dystocia; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data*; D007494:Ireland; D022125:Lacerations / Q000453:epidemiology*; D008297:Male; D010298:Parity; D010561:Personnel Staffing and Scheduling; D006473:Postpartum Hemorrhage / Q000453:epidemiology*; D011247:Pregnancy; D011446:Prospective Studies; D013997:Time Factors
keywords: morbidity; operative vaginal delivery; operator experience; prospective cohort study; time of birth