title: Induction of labour versus expectant management at term by subgroups of maternal age: an individual patient data meta-analysis.
abstract: BACKGROUND
  British women are delaying childbirth. Women aged 35 years or over have a higher risk of perinatal death. There is a linear relationship between maternal age and delivery by emergency caesarean in nulliparous women. Many obstetricians induce older women at term attempting to improve perinatal outcomes, others are reluctant for fear of increasing caesarean rates. A recent systematic review of induction of labour versus expectant management in women at term, found induction was associated with a reduction in caesareans (OR 0.83, 95% CI 0.76-0.92).
  
  
  OBJECTIVE
  To identify whether induction of labour changes the risk of caesarean section in women aged 35 years or over.
  
  
  METHODS
  
  
  
  METHODS
  Available data sets from RCTs included in the Wood et al. systematic review (31 trials) and suitable RCTs published since week 23, 2012.
  
  
  METHODS
  Studies were included if they were randomised controlled trials comparing induction of labour with expectant management at term with intact membranes with a singleton or multiple pregnancy in a cephalic presentation.
  
  
  METHODS
  A quantitative meta-analysis of individual patient data (IPD) using a random-effects model to calculate odds ratios.
  
  
  RESULTS
  In total 2675 women (five studies) were included in the meta-analysis and 2526 women (four studies) were included in the IPD meta-analysis. There was no statistically significant increase in caesarean section rates seen in either analysis.
  
  
  CONCLUSIONS
  Induction of labour in women of advanced maternal age has no statistically significant effect on caesarean section rates.
authors.affiliation: Maternity Department, Nottingham City Hospital, Nottingham University Hospitals NHS Trust, Nottingham NG5 1PB, UK. Electronic address: katefwalker@doctors.org.uk.
authors.forename: Kate F
authors.initials: KF
authors.lastname: Walker
authors.affiliation: Maternity Department, Queen's Medical Centre, Nottingham University Hospitals NHS Trust, Nottingham NG7 2UH, UK.
authors.forename: Gemma
authors.initials: G
authors.lastname: Malin
authors.affiliation: Maternity Department, Nottingham City Hospital, Nottingham University Hospitals NHS Trust, Nottingham NG5 1PB, UK.
authors.forename: Philippa
authors.initials: P
authors.lastname: Wilson
authors.affiliation: Maternity Department, Nottingham City Hospital, Nottingham University Hospitals NHS Trust, Nottingham NG5 1PB, UK.
authors.forename: Jim G
authors.initials: JG
authors.lastname: Thornton
mesh_terms: D000328:Adult; D002585:Cesarean Section / Q000706:statistics & numerical data*; D036861:Delivery, Obstetric; D005260:Female; D006801:Humans; D007751:Labor, Induced / Q000706:statistics & numerical data*; D007743:Labor, Obstetric; D008423:Maternal Age; D016017:Odds Ratio; D010298:Parity; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D047929:Term Birth
keywords: Advanced maternal age; Caesarean section; Expectant management; Induction; Systematic review