title: Reason for the increasing use of vacuum extraction in Sweden: a population-based study.
abstract: OBJECTIVE
  To explain the increasing rates of vacuum extraction in Sweden.
  
  
  METHODS
  Population-based register study.
  
  
  METHODS
  Nationwide study in Sweden.
  
  
  METHODS
  A total of 589 108 primiparous women with singleton, term live births in 1992-2010.
  
  
  METHODS
  Odds ratios with 95% confidence intervals were estimated for potential risk factors for vacuum extraction and emergency cesarean. To explain the increase in vacuum extraction over time, we successively adjusted for maternal and infant characteristics in four different models.
  
  
  METHODS
  Vacuum extraction.
  
  
  RESULTS
  Rates of vacuum extraction increased from 11.5% in 1992 to 14.8% in 2010. The risk of vacuum extraction increased with maternal age and gestational length, but decreased with increasing maternal height. The increased use of vacuum extraction over time was partly explained by increasing maternal age and increased use of epidural anesthesia. Among women with and without epidural analgesia, the increase in vacuum extraction over time was confined to vacuum extraction due to signs of fetal distress.
  
  
  CONCLUSIONS
  Depending on risk factors, the odds of being delivered by vacuum extraction can vary immensely from one woman to another. Increasing maternal age explains a substantial fraction of the increase in vacuum extraction use since 1992. Whether the increase in vacuum extractions due to fetal distress reflects a true increase in fetal distress during labor remains to be explained.
authors.affiliation: Division of Clinical Epidemiology, Department of Medicine, Karolinska Institute, Stockholm, Sweden.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Elvander
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ekéus
authors.forename: Kristina
authors.initials: K
authors.lastname: Gemzell-Danielsson
authors.forename: Sven
authors.initials: S
authors.lastname: Cnattingius
mesh_terms: D000328:Adult; D000767:Anesthesia, Epidural / Q000706:statistics & numerical data / Q000639:trends; D002585:Cesarean Section / Q000706:statistics & numerical data / Q000639:trends; D015331:Cohort Studies; D005260:Female; D005316:Fetal Distress / Q000453:epidemiology / Q000628:therapy; D006801:Humans; D008297:Male; D008423:Maternal Age; D015233:Models, Statistical; D016017:Odds Ratio; D011247:Pregnancy; D012042:Registries; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D014620:Vacuum Extraction, Obstetrical / Q000706:statistics & numerical data / Q000639:trends*
keywords: Labor; delivery; emergency cesarean section; epidural analgesia; risk factors; vacuum extraction