Cell salvage and donor blood transfusion during cesarean section: a pragmatic, multicentre randomised controlled trial (SALVO)

Research output: Contribution to journalArticlepeer-review


Colleges, School and Institutes

External organisations

  • Queen Mary, University of London
  • Birmingham Women's Hospital NHS Foundation Trust
  • University of Sheffield
  • NHS Blood and Transplant, London
  • Sheffield Teaching Hospitals NHS Foundation Trust
  • Singleton Hospital
  • Royal Infirmary of Edinburgh
  • Royal Victoria Infirmary; Newcastle Upon Tyne UK
  • Newcastle University
  • Barts Health NHS Trust


Excessive haemorrhage at cesarean section requires donor (allogeneic) blood transfusion. Cell salvage may reduce this requirement.

Methods and findings
We conducted a pragmatic randomised controlled trial (at 26 obstetric units; participants recruited from 4 June 2013 to 17 April 2016) of routine cell salvage use (intervention) versus current standard of care without routine salvage use (control) in cesarean section among women at risk of haemorrhage. Randomisation was stratified, using random permuted blocks of variable sizes. In an intention-to-treat analysis, we used multivariable models, adjusting for stratification variables and prognostic factors identified a priori, to compare rates of donor blood transfusion (primary outcome) and fetomaternal haemorrhage ≥2 ml in RhD-negative women with RhD-positive babies (a secondary outcome) between groups. Among 3,028 women randomised (2,990 analysed), 95.6% of 1,498 assigned to intervention had cell salvage deployed (50.8% had salvaged blood returned; mean 259.9 ml) versus 3.9% of 1,492 assigned to control. Donor blood transfusion rate was 3.5% in the control group versus 2.5% in the intervention group (adjusted odds ratio [OR] 0.65, 95% confidence interval [CI] 0.42 to 1.01, p = 0.056; adjusted risk difference −1.03, 95% CI −2.13 to 0.06). In a planned subgroup analysis, the transfusion rate was 4.6% in women assigned to control versus 3.0% in the intervention group among emergency cesareans (adjusted OR 0.58, 95% CI 0.34 to 0.99), whereas it was 2.2% versus 1.8% among elective cesareans (adjusted OR 0.83, 95% CI 0.38 to 1.83) (interaction p = 0.46). No case of amniotic fluid embolism was observed. The rate of fetomaternal haemorrhage was higher with the intervention (10.5% in the control group versus 25.6% in the intervention group, adjusted OR 5.63, 95% CI 1.43 to 22.14, p = 0.013). We are unable to comment on long-term antibody sensitisation effects.

The overall reduction observed in donor blood transfusion associated with the routine use of cell salvage during cesarean section was not statistically significant.

Trial registration
This trial was prospectively registered on ISRCTN as trial number 66118656 and can be viewed on http://www.isrctn.com/ISRCTN66118656.


Original languageEnglish
Article numbere1002471
JournalPLoS Medicine
Issue number12
Publication statusPublished - 19 Dec 2017


  • Intraoperative Blood Cell Salvage, Caesarean Section, Obstetrics

ASJC Scopus subject areas