title: Vacuum extraction in fetal macrosomia and risk of neonatal complications: a population-based cohort study.
abstract: BACKGROUND
  High birthweight is associated with complicated childbirth. The aim of the present study was to investigate the association between birthweight, mode of delivery, and neonatal complications among infants born at term with a birthweight ≥3000 g.
  
  
  METHODS
  This population-based cohort study used data from the Swedish Medical Birth Register from 1999 to 2012, including 1 030 775 births at >36 completed weeks. Exposure was mode of delivery, categorized into non-instrumental vaginal delivery (VD), emergency cesarean section (CS), vacuum extraction (VE) or cesarean section following attempted vacuum extraction (VE + CS), and birthweight was divided into five categories (3000-3999 g, 4000-4499 g, 4500-4999 g, and ≥5000 g). The following outcomes were assessed: 5-min Apgar score <7, neonatal convulsions, intracranial hemorrhage, and brachial plexus injury. Infants born after VD with a birthweight of 3000-3999 g were used as reference in the logistic regression analysis.
  
  
  RESULTS
  The odds ratios for all complications increased at higher birthweights among infants born after VE/VE + CS and VD. The highest risks were seen after VE/VE + CS with an adjusted odds ratio for neonatal convulsions of 2.6 (95% CI 2.1-3.2) in the reference birthweight group and 6.3 (95% CI 4.3-9.2) among infants with a birthweight of ≥4500 g. The corresponding adjusted odds ratios for intracranial hemorrhage were 2.6 (95% CI 1.7-3.9) and 6.7 (95% CI 3.3-13.6) and for brachial plexus injury 4.0 (95% CI 3.3-4.9) and 88.4 (95% CI 71.9-108.4).
  
  
  CONCLUSIONS
  Vacuum extraction is a risk factor for serious neonatal complications, in particular when used in macrosomic fetuses.
authors.affiliation: Department of Women's and Children's Health, Division of Reproductive Health, Karolinska Institute, Stockholm, Sweden. katarina.aberg@ki.se.
authors.forename: Katarina
authors.initials: K
authors.lastname: Åberg
authors.affiliation: Department of Clinical Science Intervention and Technology, Karolinska Institute, Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Norman
authors.affiliation: Department of Clinical Science Intervention and Technology, Karolinska Institute, Stockholm, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Pettersson
authors.affiliation: Department of Women's and Children's Health, Division of Reproductive Health, Karolinska Institute, Stockholm, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ekéus
mesh_terms: D001034:Apgar Score; D001720:Birth Injuries / Q000453:epidemiology*; D002585:Cesarean Section / Q000706:statistics & numerical data; D015331:Cohort Studies; D005260:Female; D005320:Fetal Macrosomia / Q000453:epidemiology / Q000601:surgery*; D006801:Humans; D007231:Infant, Newborn; D007744:Obstetric Labor Complications / Q000517:prevention & control*; D011247:Pregnancy; D012042:Registries; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D014620:Vacuum Extraction, Obstetrical / Q000706:statistics & numerical data*
keywords: Fetal macrosomia; high birthweight; instrumental delivery; neonatal outcome; vacuum extraction