title: Why is post-partum haemorrhage more common in women with congenital heart disease?
abstract: OBJECTIVE
  To identify the factors associated with an increased post-partum blood loss in women with congenital heart disease (CHD).
  
  
  METHODS
  The study was a retrospective cohort study, which included 366 nulliparous women with CHD and a singleton pregnancy cared for in a single tertiary centre (Chelsea and Westminster Hospital) between 1994 and 2014. The women were classified into one of 12 different functional groups and univariate and multivariate regression analysis were used to identify factors associated with increased blood loss at delivery.
  
  
  RESULTS
  The average volume of blood loss in women with CHD was twice that expected. Univariate analysis showed that White European women had the lowest blood loss. Women who had been on anticoagulants, had a forceps delivery, emergency Caesarean section or general anaesthesia lost more blood than those having a spontaneous vaginal birth under regional analgesia. Higher CARPREG scores were associated strongly with increased blood loss. Women with a Fontan circulation had the highest blood loss and the difference remained significant after correcting for other significant variables.
  
  
  CONCLUSIONS
  Women with CHD are at increased risk of PPH. We have identified several potentially modifiable risk factors that may be targeted to reduce this risk. In addition, women with a Fontan circulation were most prone to PPH, independent of other risk factors, suggesting the existence of lesion-specific abnormalities and the need for extra vigilance in this group of women at the time of birth.
authors.affiliation: Academic Department of Obstetrics and Gynaecology, Imperial College London, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK. Electronic address: matthew.cauldwell@imperial.ac.uk.
authors.forename: Matthew
authors.initials: M
authors.lastname: Cauldwell
authors.affiliation: Adult Congenital Heart Centre, The National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.
authors.forename: Kate
authors.initials: K
authors.lastname: Von Klemperer
authors.affiliation: Adult Congenital Heart Centre, The National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.
authors.forename: Anselm
authors.initials: A
authors.lastname: Uebing
authors.affiliation: Adult Congenital Heart Centre, The National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.
authors.forename: Lorna
authors.initials: L
authors.lastname: Swan
authors.affiliation: Academic Department of Obstetrics and Gynaecology, Imperial College London, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Steer
authors.affiliation: Adult Congenital Heart Centre, The National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Gatzoulis
authors.affiliation: Academic Department of Obstetrics and Gynaecology, Imperial College London, Chelsea and Westminster Hospital, 369 Fulham Road, London SW10 9NH, UK.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Johnson
mesh_terms: D000328:Adult; D005260:Female; D018729:Fontan Procedure / Q000009:adverse effects; D006330:Heart Defects, Congenital / Q000150:complications / Q000601:surgery*; D006801:Humans; D006473:Postpartum Hemorrhage / Q000453:epidemiology*; D011247:Pregnancy; D012189:Retrospective Studies; D012307:Risk Factors; D055815:Young Adult
keywords: Blood loss; Cardiac disease; Risk factors