title: Prolonged second stage of labour and the risk for subsequent preterm birth.
abstract: OBJECTIVE
  To assess whether prolonged second stage of labour influences the gestational age at the subsequent delivery.
  
  
  METHODS
  We performed a retrospective cohort study. Clinical information was retrieved from the McGill Obstetrical and Neonatal Database for the period of January 2001 to February 2008. We evaluated primiparous women with term singleton pregnancies who reached the second stage of labour. Women were divided into two groups, according to the duration of the second stage: delivery after more than three hours of full cervical dilatation, or delivery within three hours. The primary outcome measured was the incidence of spontaneous preterm births at the subsequent delivery.
  
  
  RESULTS
  Among 1818 women whose records were available for analysis, 416 women (22.9%) had a prolonged second stage of labour in their first delivery. Women with a prolonged second stage in their first delivery did not deliver prematurely more often in the successive delivery than those women whose second stage was not prolonged (rate of preterm birth 4.3% in the prolonged second stage group and 5.5% in the normal second stage group; P = 0.3).
  
  
  CONCLUSIONS
  In our population of primiparous women with a singleton term delivery, a prolonged second stage of labour lasting more than three hours was not associated with preterm birth at their subsequent delivery.
authors.affiliation: McGill University Health Centre, Montreal QC; Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Royal Victoria Hospital, McGill University, Montreal QC.
authors.forename: Yael
authors.initials: Y
authors.lastname: Sciaky-Tamir
authors.affiliation: McGill University Health Centre, Montreal QC; Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Royal Victoria Hospital, McGill University, Montreal QC.
authors.forename: Alon
authors.initials: A
authors.lastname: Shrim
authors.affiliation: McGill University Health Centre, Montreal QC; Department of Obstetrics and Gynecology, Division of Maternal Fetal Medicine, Royal Victoria Hospital, McGill University, Montreal QC.
authors.forename: Richard N
authors.initials: RN
authors.lastname: Brown
mesh_terms: D000328:Adult; D002170:Canada / Q000453:epidemiology; D036861:Delivery, Obstetric / Q000379:methods / Q000706:statistics & numerical data; D003710:Demography; D005260:Female; D005865:Gestational Age; D006801:Humans; D007748:Labor Stage, Second / Q000502:physiology*; D010298:Parity; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012959:Socioeconomic Factors; D013997:Time Factors
keywords: cervical incompetence; preterm birth; prolonged second stage of labour; risk factors