Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Nov;32(13):1225-30.
doi: 10.1055/s-0035-1552940. Epub 2015 May 22.

Accuracy of Estimated Blood Loss in Predicting Need for Transfusion after Delivery

Shayna N Conner  1 , Methodius G Tuuli  1 , Ryan Colvin  1 , Anthony L Shanks  1 , George A Macones  1 , Alison G Cahill  1
Affiliations

Accuracy of Estimated Blood Loss in Predicting Need for Transfusion after Delivery

Shayna N Conner et al. Am J Perinatol. 2015 Nov.

Abstract

Objective: The definition of postpartum hemorrhage (PPH) was developed more than 50 years ago. Since then, the obstetric population has changed dramatically. We sought to determine how well we estimated blood loss (EBL) and find thresholds predicting need for transfusion.

Study design: We performed a prospective cohort study from 2010 to 2012, comparing those who needed transfusion postpartum and those who did not. EBL, calculated EBL (cEBL), and change in hematocrit were calculated for patients who did not receive transfusion, and EBL was calculated for those who did receive transfusion, stratified by delivery type. Receiver operator curves were created and optimal thresholds of EBL to predict transfusion were estimated.

Results: Among 4,804 patients, transfusion was required for 0.65% of vaginal and 8.7% of cesarean deliveries. Median EBL was higher in women requiring transfusion. A weak correlation was noted between EBL and cEBL for all deliveries. Thresholds of 500 mL blood loss for vaginal delivery and 1,000 mL for cesarean had the best predictive ability for transfusion.

Conclusion: In this modern obstetric, cohort EBL is weakly correlated with cEBL, suggesting that accuracy of clinical estimates of blood loss is modest. However, EBL predicts need for transfusion, with optimal thresholds of 500 mL for a vaginal delivery and 1,000 mL in a cesarean. This validates the traditional definitions of PPH in our modern population.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Correlation between EBL and cEBL for vaginal deliveries. cEBL, calculated estimated blood loss; EBL, estimated blood loss.
Fig. 2
Fig. 2
Correlation between EBL and cEBL for cesarean deliveries. cEBL, calculated estimated blood loss; EBL, estimated blood loss.
Fig. 3
Fig. 3
Receiver operator curve for the ability of EBL to predict need for transfusion in vaginal deliveries. EBL, estimated blood loss.
Fig. 4
Fig. 4
Receiver operator curve for the ability of EBL to predict need for transfusion in cesarean deliveries. EBL, estimated blood loss.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Hoyert DL. Maternal mortality and related concepts. National Center for Health Statistics Vital Health Stat. 2007;3(33):1–13. - PubMed
    1. Callaghan WM. Overview of maternal mortality in the United States. Semin Perinatol. 2012;36(1):2–6. - PubMed
    1. Haeri S, Dildy GA., III Maternal mortality from hemorrhage. Semin Perinatol. 2012;36(1):48–55. - PubMed
    1. Callaghan WM, Kuklina EV, Berg CJ. Trends in postpartum hemorrhage: United States, 1994-2006. Am J Obstet Gynecol. 2010;202(4):353.e1–353.e6. - PubMed
    1. Newton M, Mosey LM, Egli GE, Gifford WB, Hull CT. Blood loss during and immediately after delivery. Obstet Gynecol. 1961;17:9–18. - PubMed

Publication types