title: Time to subsequent live birth according to mode of delivery in the first birth.
abstract: OBJECTIVE
  To estimate the rate and time to next live birth by mode of delivery.
  
  
  METHODS
  Hospital-based cohort.
  
  
  METHODS
  Aarhus University Hospital (AUH), Denmark.
  
  
  METHODS
  All pregnant women attending AUH were invited to enroll in the Aarhus Birth Cohort (ABC) study between 1989 and 2010 (n = 91,625).
  
  
  METHODS
  Women were followed from their first live birth until the subsequent live birth or until censoring due to study end using Cox regression models.
  
  
  METHODS
  Rate and time to subsequent live birth according to mode of delivery.
  
  
  RESULTS
  46,162 index live births were identified, of which 22,462 (49%) had a subsequent live birth. Women with any type of caesarean had a 6% reduction in the rate of subsequent live birth (HR 0.94, 95% CI 0.89, 0.98), which remained unchanged in the analysis by type (emergency, HR 0.95, 95% CI 0.89, 1.02; elective, HR 0.91, 95% CI 0.85, 0.98) compared with women who had a spontaneous vaginal delivery (SVD). Operative vaginal delivery was associated with an 8% reduction in subsequent live birth rates (HR 0.92, 95% CI 0.86, 0.98) and vaginal delivery complicated by shoulder dystocia with a 19% reduction compared with SVD. Median time to next birth in days was shortest in women with a first caesarean (994 days, 95% CI 973, 1026) and longest in women with a vaginal delivery complicated by shoulder dystocia (1065 days, 95% CI 994, 1191). In women with planned pregnancies, the shortest median time to second birth was in women with breech vaginal deliveries (859 days, 95% CI 737, 1089) and the longest in women with vaginal deliveries complicated by shoulder dystocia (1193 days, 95% CI 1028, 1430).
  
  
  CONCLUSIONS
  The impact of mode of delivery on subsequent rate and time to next birth was minimal in this study. The greatest reduction was among women with assisted vaginal delivery complicated by shoulder dystocia. This study is strengthened by data on pregnancy planning as well as information on complications of pregnancy, delivery and neonatal morbidities, all of which may influence a woman's decision on subsequent birth.
authors.affiliation: National Perinatal Epidemiology Centre, Cork University Maternity Hospital, Cork, Ireland.|The Irish Centre for Fetal and Neonatal Translational Research, Cork University Maternity Hospital, Cork, Ireland.
authors.forename: S M
authors.initials: SM
authors.lastname: O'Neill
authors.affiliation: The Irish Centre for Fetal and Neonatal Translational Research, Cork University Maternity Hospital, Cork, Ireland.|Department of Epidemiology and Public Health, University College Cork, Cork, Ireland.
authors.forename: A S
authors.initials: AS
authors.lastname: Khashan
authors.affiliation: The Irish Centre for Fetal and Neonatal Translational Research, Cork University Maternity Hospital, Cork, Ireland.
authors.forename: L C
authors.initials: LC
authors.lastname: Kenny
authors.affiliation: Department of Epidemiology and Public Health, University College Cork, Cork, Ireland.
authors.forename: P M
authors.initials: PM
authors.lastname: Kearney
authors.affiliation: National Centre for Register-based Research, Aarhus University, Aarhus, Denmark.
authors.forename: P B
authors.initials: PB
authors.lastname: Mortensen
authors.affiliation: National Perinatal Epidemiology Centre, Cork University Maternity Hospital, Cork, Ireland.
authors.forename: R A
authors.initials: RA
authors.lastname: Greene
authors.affiliation: National Centre for Register-based Research, Aarhus University, Aarhus, Denmark.|Centre for Integrated Register-based Research, Aarhus University, Aarhus, Denmark.
authors.forename: E
authors.initials: E
authors.lastname: Agerbo
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Paediatrics, Aarhus University Hospital, Skejby, Aarhus N, Denmark.
authors.forename: N
authors.initials: N
authors.lastname: Uldbjerg
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Paediatrics, Aarhus University Hospital, Skejby, Aarhus N, Denmark.
authors.forename: T B
authors.initials: TB
authors.lastname: Henriksen
mesh_terms: D000328:Adult; D001723:Birth Rate; D002585:Cesarean Section / Q000706:statistics & numerical data*; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D003718:Denmark / Q000453:epidemiology; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data*; D005260:Female; D005298:Fertility; D006801:Humans; D007231:Infant, Newborn; D050498:Live Birth / Q000453:epidemiology*; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011446:Prospective Studies; D013997:Time Factors
keywords: Birth cohort; caesarean delivery; sub-fertility; time to next birth