title: Trial of labour after caesarean section and the risk of neonatal and infant death: a nationwide cohort study.
abstract: Caesarean section (CS) rates are increasing worldwide and as a result repeat CS is common. The optimal mode of delivery in women with one previous CS is widely debated and the risks to the infant are understudied. The aim of the current study was to evaluate if women with a trial of labour after caesarean (TOLAC) had an increased odds of neonatal and infant death compared to women with an elective repeat CS (ERCS).
  
  
  
  A population register-based cohort study was conducted in Denmark between 1982 and 2010. All women with two deliveries [in which the first was a CS, and the second was an uncomplicated, term delivery (n = 61,626)] were included in the study. Logistic regression models were used to report adjusted odds ratios (AOR) and 95% confidence intervals (CI) of the odds of death according to mode of delivery. The main outcome measures were neonatal death (early and late) and infant death.
  
  
  
  Women with a TOLAC had an increased odds of neonatal death (AOR 1 · 87, 95% CI 1 · 12 to 3 · 12) due to an increased risk of early neonatal death (AOR 2 · 06, 95% CI 1 · 19 to 3 · 56) and no effect on late neonatal death (AOR 0 · 97, 95% CI 0 · 22 to 4 · 32), or infant death (AOR 1 · 12, 95% CI 0 · 79 to 1 · 59) when compared to the reference group of women with an ERCS. There was evidence of a cohort effect as the increased odds of neonatal death (AOR 3 · 89, 95% CI 1 · 33 to 11 · 39) was most significant in the earlier years (1982-1991) and gradually disappeared (AOR 1 · 01, 95% CI 0 · 44 to 2 · 31) in the later years (2002-2010).
  
  
  
  Although an increased risk of neonatal death was found in women with a TOLAC, there was evidence of a cohort effect, which showed this increased odds disappearing over time. Advances in modern healthcare including improved monitoring and earlier detection of underlying pregnancy complications may explain the findings.
authors.affiliation: The Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork University Maternity Hospital, University College Cork, Wilton, Cork, Ireland. sinead.oneill@ucc.ie.|National Perinatal Epidemiology Centre (NPEC), Department of Obstetrics and Gynaecology, Cork University Maternity Hospital, 5th Floor Wilton, Cork, Ireland. sinead.oneill@ucc.ie.
authors.forename: Sinéad M
authors.initials: SM
authors.lastname: O'Neill
authors.affiliation: Centre for Integrated Register-based Research (CIRRAU), National Centre for Register-based Research (NCRR), Aarhus University, Aarhus, Denmark.
authors.forename: Esben
authors.initials: E
authors.lastname: Agerbo
authors.affiliation: The Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork University Maternity Hospital, University College Cork, Wilton, Cork, Ireland.|Department of Epidemiology and Public Health, University College Cork, Western Gateway Building, Cork, Ireland.
authors.forename: Ali S
authors.initials: AS
authors.lastname: Khashan
authors.affiliation: Department of Epidemiology and Public Health, University College Cork, Western Gateway Building, Cork, Ireland.
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Kearney
authors.affiliation: Perinatal Epidemiology Research Unit, Department of Paediatrics, Aarhus University Hospital, Skejby, Aarhus N, DK-8200, Denmark.
authors.forename: Tine Brink
authors.initials: TB
authors.lastname: Henriksen
authors.affiliation: National Perinatal Epidemiology Centre (NPEC), Department of Obstetrics and Gynaecology, Cork University Maternity Hospital, 5th Floor Wilton, Cork, Ireland.
authors.forename: Richard A
authors.initials: RA
authors.lastname: Greene
authors.affiliation: The Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork University Maternity Hospital, University College Cork, Wilton, Cork, Ireland.
authors.forename: Louise C
authors.initials: LC
authors.lastname: Kenny
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D017604:Cesarean Section, Repeat; D015331:Cohort Studies; D003718:Denmark; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D007223:Infant; D066088:Infant Death; D007231:Infant, Newborn; D016015:Logistic Models; D016017:Odds Ratio; D066087:Perinatal Death; D011247:Pregnancy; D012042:Registries; D012306:Risk; D014219:Trial of Labor; D055815:Young Adult
keywords: Neonatal death; Repeat Caesarean section; Trial of labour