title: Risk factors for failed vacuum extraction and associated complications in term newborn infants: a population-based cohort study.
abstract: OBJECTIVE
  The aims of the present study were to investigate risk factors for failed vacuum extraction (VE), and to compare neonatal complications among infants delivered by failed VE with those delivered by successful VE.
  
  
  METHODS
  Population-based study including all women (and their newborn infants) with singleton pregnancy who gave birth at term by failed VE (n = 4747) or successful VE (n = 83 671) in Sweden between 1999 and 2010. Failed VE was defined as VE followed by an emergency cesarean section (ECS), forceps, or both forceps and ECS. We used logistic regression to examine the association between failed VE in relation to intracranial hemorrhage, subgaleal hemorrhage, Apgar scores <7 at 5 min, and neonatal convulsions.
  
  
  RESULTS
  Risk factors for failed VE included occipito posterior position, mid-pelvic fetal station, high birth weight, short maternal stature, epidural analgesia, and induction of labor. Compared with infants born after a successful VE, those delivered by failed VE had a higher risk of subgaleal hemorrhage OR 7.3 CI (5.5-9.7), convulsions OR 1.9 CI (1.4-2.7), and low Apgar OR 2.6 CI (2.3-3.0), but not of ICH.
  
  
  CONCLUSIONS
  Failed VE is associated with neonatal complications. Fetal head position and station should be carefully assessed prior to the extraction.
authors.affiliation: a Department of Women's and Children's Health, Division of Reproductive Health and.
authors.forename: Mia
authors.initials: M
authors.lastname: Ahlberg
authors.affiliation: b Department of Clinical Science, Intervention and Technology, Division of Pediatrics , Karolinska Institutet , Stockholm , Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Norman
authors.affiliation: a Department of Women's and Children's Health, Division of Reproductive Health and.
authors.forename: Anna
authors.initials: A
authors.lastname: Hjelmstedt
authors.affiliation: a Department of Women's and Children's Health, Division of Reproductive Health and.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ekéus
mesh_terms: D000328:Adult; D001720:Birth Injuries / Q000209:etiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D011247:Pregnancy; D012307:Risk Factors; D017211:Treatment Failure; D014620:Vacuum Extraction, Obstetrical / Q000009:adverse effects* / Q000706:statistics & numerical data; D055815:Young Adult
keywords: Convulsions; epidemiology; failed vacuum extraction; intracranial hemorrhage; low Apgar scores; obstetrics; subgaleal hematoma; vacuum extraction delivery