title: Maternal age and emergency operative deliveries at term: a population-based registry study among low-risk primiparous women.
abstract: OBJECTIVE
  To study the association between maternal age and emergency operative delivery. The roles of in-labour indications, and birthweight ≥ 4000 g, gestational age ≥ 42 weeks, induction of labour, and epidural use, according to maternal age were explored.
  
  
  METHODS
  Population-based study.
  
  
  METHODS
  Medical Birth Registry of Norway and Statistics Norway.
  
  
  METHODS
  We studied 169 583 low-risk primiparous mothers with singleton, cephalic labours, at ≥37 weeks of gestation, from 1999 to 2009.
  
  
  METHODS
  The associations between maternal age and mode of delivery were analysed using multinomial regression analyses, adjusting for sociodemographic factors.
  
  
  METHODS
  Emergency caesarean section and operative vaginal delivery.
  
  
  RESULTS
  Of women aged ≥40 years, 22% had emergency caesarean sections and 24% had operative vaginal deliveries, giving adjusted relative risk ratios (RRRs) of 6.60 (95% confidence interval, 95% CI 5.53-7.87) and 3.30 (95% CI 2.79-3.90), respectively, when compared with women aged 20-24 years. Adjustments for sociodemographic factors only slightly changed the estimates. Dystocia was the main indication, followed by fetal distress. All of the listed factors increased the level of emergency operative deliveries, mainly because of an increase in dystocia. The increase in risk for emergency caesarean section by all factors, and for operative vaginal deliveries by epidural, were greater in older than in younger women, but were significant for epidural only.
  
  
  CONCLUSIONS
  We found a close association between maternal age and emergency operative delivery in low-risk primiparas. Contributory factors increased the risk for both emergency operative delivery and epidural more in older than in younger women.
authors.affiliation: Women and Children's Division, Norwegian Resource Centre for Women's Health, Oslo University Hospital, Rikshospitalet, Norway.
authors.forename: L
authors.initials: L
authors.lastname: Herstad
authors.affiliation: Medical Birth Registry of Norway, Norwegian Institute of Public Health, Bergen, Norway.|Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Klungsøyr
authors.affiliation: Medical Birth Registry of Norway, Norwegian Institute of Public Health, Bergen, Norway.|Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: R
authors.initials: R
authors.lastname: Skjaerven
authors.affiliation: University of Oslo, Oslo, Norway.|Department of Gynaecology, Oslo University Hospital Rikshospitalet, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Tanbo
authors.affiliation: Women and Children's Division, Norwegian Resource Centre for Women's Health, Oslo University Hospital, Rikshospitalet, Norway.|Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: L
authors.initials: L
authors.lastname: Forsén
authors.affiliation: University of Oslo, Oslo, Norway.|Department of Obstetrics, Oslo University Hospital Rikshospitalet, Oslo, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Åbyholm
authors.affiliation: Women and Children's Division, Norwegian Resource Centre for Women's Health, Oslo University Hospital, Rikshospitalet, Norway.|Division of Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Vangen
mesh_terms: D000328:Adult; D016362:Analgesia, Obstetrical / Q000706:statistics & numerical data*; D001724:Birth Weight; D002585:Cesarean Section / Q000706:statistics & numerical data*; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D004420:Dystocia / Q000453:epidemiology*; D005113:Extraction, Obstetrical / Q000706:statistics & numerical data*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007751:Labor, Induced / Q000706:statistics & numerical data*; D008423:Maternal Age; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D007744:Obstetric Labor Complications / Q000453:epidemiology*; D016017:Odds Ratio; D011247:Pregnancy; D012042:Registries; D012307:Risk Factors
keywords: Emergency caesarean section; epidural; indications; low-risk population; maternal age; operative vaginal delivery