title: Maternal and perinatal consequences of antepartum haemorrhage of unknown origin.
abstract: OBJECTIVE
  To explore the risk of adverse maternal and perinatal outcomes in women with antepartum bleeding of unknown origin (ABUO).
  
  
  METHODS
  Cohort study based on data extracted from the Aberdeen Maternity and Neonatal Databank. Exposure was antepartum haemorrhage occurring after the first trimester not attributable to placenta praevia or placental abruption.
  
  
  METHODS
  Aberdeen Maternity Hospital, Aberdeen, Scotland, UK.
  
  
  METHODS
  All primigravidae delivering between 1976 and 2010.
  
  
  METHODS
  Data were analysed using univariate and multivariate statistical methods.
  
  
  METHODS
  Pre-eclampsia, induced labour, mode of delivery, preterm delivery, postpartum haemorrhage, admission to neonatal unit, perinatal death.
  
  
  RESULTS
  Between 1976 and 2010, there were 7517 women with ABUO and 68,423 women without ABUO in the cohort. Women with ABUO were more likely to be non-smokers, belong to a lower social class, and have a higher body mass index. ABUO was a significant risk factor for induced labour (adjusted odds ratio, aOR, 1.23; 95% CI 1.16-1.31), preterm delivery at <37 weeks of gestation (aOR 2.30; 95% CI 2.11-2.50), and postpartum haemorrhage (aOR 1.15; 95% CI 1.06-1.25). There was no significant association detected with pre-eclampsia (aOR 0.93; 95% CI 0.83-1.05). Whereas there was an increased risk of low birthweight (aOR 0.90; 95% CI 0.79-1.03) and stillbirth (aOR 0.92; 95% CI 0.66-1.30) with ABUO on univariate analysis, once adjusted for confounding factors this risk was non-significant.
  
  
  CONCLUSIONS
  Pregnancies complicated by ABUO are at a greater risk of preterm delivery and induced labour. There was no increase seen in perinatal mortality after adjusting for preterm birth.
authors.affiliation: Epidemiology Group, Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: S
authors.initials: S
authors.lastname: Bhandari
authors.forename: E A
authors.initials: EA
authors.lastname: Raja
authors.forename: A
authors.initials: A
authors.lastname: Shetty
authors.forename: S
authors.initials: S
authors.lastname: Bhattacharya
mesh_terms: D000328:Adult; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D007751:Labor, Induced / Q000706:statistics & numerical data; D015999:Multivariate Analysis; D054238:Perinatal Mortality; D006473:Postpartum Hemorrhage / Q000453:epidemiology*; D011225:Pre-Eclampsia / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000453:epidemiology*; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D012959:Socioeconomic Factors; D050497:Stillbirth / Q000453:epidemiology; D014592:Uterine Hemorrhage / Q000453:epidemiology*; D055815:Young Adult
keywords: Antepartum haemorrhage of unknown origin; maternal outcomes; perinatal outcomes; preterm delivery