title: Placental abruption and premature rupture of membranes.
abstract: OBJECTIVE
  To assess whether premature rupture of membranes (PROM) is associated with placental abruption.
  
  
  METHODS
  Population-based study.
  
  
  METHODS
  Data were extracted from the Medical Birth Registry of Norway.
  
  
  METHODS
  All women with PROM (18,889 cases), including 3,077 cases of preterm premature rupture of membranes (p-PROM), among a total of 355 416 singleton births in Norway during 1999-2005 with gestational age 17-44 weeks.
  
  
  METHODS
  Logistic regression was used to assess whether placental abruption was associated with PROM in preterm and term births.
  
  
  METHODS
  Placental abruption.
  
  
  RESULTS
  The occurrence of placental abruption in p-PROM was higher than in the total study population, 11.0 per 1,000 (34 of 3 077) vs. 4.2 per 1 000 (1 495 of 355 416; adjusted odds ratio 2.6, 95% confidence interval 1.8-3.7). Restricting the analyses to preterm births, the occurrence of placental abruption was less in p-PROM (11.0 per 1,000) than in births without p-PROM (36.1 per 1 000; adjusted odds ratio 0.3, 95% confidence interval 0.2-0.4). In term births, no statistically significant association was observed.
  
  
  CONCLUSIONS
  The findings suggest that in p-PROM the risk of placental abruption is not higher than in other preterm births; rather the opposite. However, comparing the risks in p-PROM and the total gestational age range, the present study confirmed results reported in previous studies of a higher risk of placental abruption in p-PROM than in the total birth population.
authors.affiliation: Institute of Clinical Medicine, University of Bergen, Bergen, Norway.
authors.forename: Vibecke Høgberg
authors.initials: VH
authors.lastname: Markhus
authors.forename: Svein
authors.initials: S
authors.lastname: Rasmussen
authors.forename: Stein Atle
authors.initials: SA
authors.lastname: Lie
authors.forename: Lorentz M
authors.initials: LM
authors.lastname: Irgens
mesh_terms: D000037:Abruptio Placentae / Q000453:epidemiology*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology*; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007234:Infant, Premature; D009664:Norway / Q000453:epidemiology; D011247:Pregnancy; D012042:Registries; D012189:Retrospective Studies