Quantification of blood loss for the diagnosis of postpartum hemorrhage: a systematic review and meta-analysis

Ruiz, Mariana Torreglosa; Azevedo, Nayara Freitas; Resende, Cynthya Viana de; Rodrigues, Wellington Francisco; Meneguci, Joilson; Contim, Divanice; Wernet, Monika; Oliveira, Carlo José Freire de

doi:10.1590/0034-7167-2023-0070

Mariana Torreglosa Ruiz Corresponding author: Mariana Torreglosa Ruiz , E-mail: marianatorreglosa@hotmail.com

study/research conception or design

data analysis and/or interpretation

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0002-5199-7328

Nayara Freitas Azevedo

study/research conception or design

data analysis and/or interpretation

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0001-7748-4777

Cynthya Viana de Resende

data analysis and/or interpretation

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0003-1203-2504

Wellington Francisco Rodrigues

study/research conception or design

data analysis and/or interpretation

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0002-3426-2186

Joilson Meneguci

data analysis and/or interpretation

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro, Hospital de Clínicas. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0003-2268-3589

Divanice Contim

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0001-5213-1465

Monika Wernet

final review with critical and intellectual participation in the manuscript

Universidade Federal de São Carlos. São Carlos, São Paulo, Brazil

https://orcid.org/0000-0002-1194-3261

Carlo José Freire de Oliveira

study/research conception or design

data analysis and/or interpretation

final review with critical and intellectual participation in the manuscript

Universidade Federal do Triângulo Mineiro. Uberaba, Minas Gerais, Brazil

https://orcid.org/0000-0003-2211-7333

Corresponding author: Mariana Torreglosa Ruiz , E-mail: marianatorreglosa@hotmail.com

Database	Search strategy in March 2022
PubMed/ MEDLINE	(postpartum hemorrhage [MeSH Terms] OR postpartum hemorrhage OR postpartum bleeding OR hemorrhage, Postpartum Immediate OR Hemorrhage, Immediate Postpartum OR Postpartum Hemorrhage, Immediate OR Delayed Postpartum Hemorrhage OR Hemorrhage, Delayed Postpartum OR Postpartum Hemorrhage, Delayed) AND Quantification of blood loss
CINAHL	(MH “Postpartum Hemorrhage/PC”) OR TI ((“postpartum hemorrhage” OR “postpartum bleeding” OR pph OR “postpartum haemorrhage”) OR AB ((“postpartum hemorrhage” OR “postpartum bleeding” OR pph OR “postpartum haemorrhage”) AND (quantification of blood loss)
Embase	(postpartum hemorrhage) AND (quantification of blood loss)
LILACS	(Hemorragia Pós-Parto OR Postpartum Hemorrhage OR Hemorragia Posparto) AND (Labor Stage, Third OR Terceira Fase do Trabalho de Parto OR Tercer Periodo del Trabajo de Parto) (prevenção & controle or prevention & control or prevención & control) AND (quantification of blood loss)
Web of Science	(postpartum hemorrhage) AND (quantification of blood loss or gravimetric measurement of blood)
Scopus	(postpartum hemorrhage OR postpartum bleeding OR hemorrhage, Postpartum Immediate OR Hemorrhage, Immediate Postpartum or Postpartum Hemorrhage, Immediate OR Delayed Postpartum Hemorrhage OR Hemorrhage, Delayed Postpartum OR Postpartum Hemorrhage, Delayed) AND (quantification of blood loss)

Author(s) and reference	Year of publication	Country	Objectives	Number of participants	Design	Intervention and comparator	Outcomes	Main findings	Risk of bias^*
Al Kadri HM, Al Anazi BK & Tamim HM(²⁹29 Al Kadri HM, Al Anazi BK, Tamim HM. Visual estimation versus gravimetric measurement of postpartum blood loss: a prospective cohort study. Arch Gynecol Obstet. 2011;283(6):1207-13. https://doi.org/10.1007/s00404-010-1522-1 https://doi.org/10.1007/s00404-010-1522-... )	2011	Saudi Arabia	Compare the accuracy of visually estimated postpartum blood loss with gravimetry.	150 women who had vaginal childbirths	Cohort study Included: women who had vaginal childbirths Excluded: postpartum women who received blood transfusion within 24 hours after childbirth and those who had antepartum hemorrhage	Intervention: gravimetry Control: visual estimation (VE) Reference: drop in Hb level	There was a difference between the means of 304.1 ml (gravimetry) and 213-214 ml (VE). There were no differences between the VE performed by a doctor or a nurse. VE led to 30% in the estimation error, when compared to drop in Hb.	Gravimetry showed a statistically significant difference.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Ambardekar S, Shochet T, Bracken H, Coyaji K, Winikoff B(²³23 Ambardekar S, Shochet T, Bracken H, Coyaji K, Winikoff B. Calibrated delivery drape versus indirect gravimetric technique for the measurement of blood loss after delivery: a randomized trial. BMC Pregnancy Childbirth. 2014;14:276. https://doi.org/10.1186/1471-2393-14-276 https://doi.org/10.1186/1471-2393-14-276... )	2014	India	Compare the results of quantification of blood loss with gravimetry techniques using a calibrated field.	900 women who had vaginal childbirths (the sample size calculated to test a 50 ml difference between techniques, with 80% power and 5% significance, was 900 women, and 450 were allocated to each study arm)	Randomized clinical trial Inclusion criteria: over 18 years old who had vaginal childbirth as an outcome; excluded women undergoing cesarean section Allocated into 02 groups (intervention and comparator) Losses measured from cord clamping to 1 hour after childbirth or until the bleeding stops. Hb dosage was performed 24 hours after	Intervention: BRASSS-V drape^® (graduated and calibrated field) Comparator: gravimetry Reference: drop in Hb level 24 hours after childbirth	The mean estimate was 253.9 ± 218.2 (20 - 1600 ml) for the calibrated field group and 195.3 ± 201.8 (20 - 2000 ml) for the gravimetry group.	There were important differences in quantification. The calibrated and graduated field showed greater accuracy and should be considered in care protocols. As limitations, the authors cited the failure to record the start and end time of collection, losses during weighing/measurement that were not measured, fluid replacement was not calculated, and that the study’s testing was only for vaginal childbirths.	11/13 (there is no information regarding blinding of participants and evaluators)
Blosser C, Smith A, Poole AT(¹⁷17 Blosser C, Smith A, Poole AT. Quantification of blood loss improves detection of postpartum hemorrhage and accuracy of postpartum hemorrhage rates: a retrospective cohort study. Cureus. 2021;13(2):e13591. https://doi.org/10.7759/cureus.13591 https://doi.org/10.7759/cureus.13591... )	2021	United States	Analyze differences between VE and calibrated field quantification of postpartum blood loss.	5,445 childbirths, regardless of the type of childbirth Groups: 828 cesarean sections in the field group and 848 VE, 1,877 vaginal in the field group and 1,883 VE	Cohort study Exclusion criteria: gestational age less than 20 gestational weeks Analyzed the need for blood transfusion based on drop in Ht	Intervention: calibrated and graduated field Comparator: VE Reference: drop in Ht level	There was a difference between the means in the groups, with 2.1% of losses greater than 1,000 ml being detected in VE and 6.5%, when quantified by the field. Quantification proved to be the best predictor for assessing the need for blood transfusion for all types of childbirth.	Quantification of blood loss was the most sensitive test to detect clinically significant losses.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Doctorvaladan SV, et al.(¹⁸18 Doctorvaladan SV, Jelks AT, Hsieh EW, Thurer RL, Zakowski MI, Lagrew DC. Accuracy of blood loss measurement during cesarean delivery. AJP Rep. 2017;7(2):e93-e100. https://doi.org/10.1055/s-0037-1601382 https://doi.org/10.1055/s-0037-1601382... )	2017	United States	Compare the accuracy of VE and gravimetry techniques with colorimetry to determine post-cesarean blood loss.	50 women undergoing cesarean section	Observational study Compared VE, gravimetry and colorimetry from an automated device	Intervention: colorimetry Comparators: VE and gravimetry Reference: drop in Hb level	Different means were obtained when compared with the techniques: 928 ml for VE; 822 ml for gravimetry; and 572 for colorimetry.	Colorimetry proved to be the best predictor for measuring blood loss, using drop in Hb as a reference, showing greater accuracy.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Hire MG, Lange E, Vaidyanathan M, Armour K L & Toledo P(¹⁹19 Hire MG, Lange EMS, Vaidyanathan M, Armour KL, Toledo P. Effect of quantification of blood loss on activation of a postpartum hemorrhage protocol and use of resources. J Obstet Gynecol Neonatal Nurs. 2020;49(2):137-43. https://doi.org/10.1016/j.jogn.2020.01.002 https://doi.org/10.1016/j.jogn.2020.01.0... )	2020	United States	Determine whether blood loss colorimetry can reduce interventions and diagnoses of PPH in cesarean childbirths compared with VE.	42 cesarean sections	Observational study Cases in which visual loss greater than 1,000 ml was estimated were selected.	Intervention: colorimetry Comparator: VE Reference: Hb dosage	The mean visually estimated was 1,275 ml (1,100-1,510 ml). The mean obtained by colorimetry was 948 ml (700-1,267 ml). 57% of visually estimated cases were not classified as PPH by the device.	There was an overestimation of loss, when assessed by VE, and PPH protocols could have been installed unnecessarily.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Katz et al.⁽²⁰20 Katz D, Wang R, O'Neil L, Gerber C, Lankford A, Rogers T, et al. The association between the introduction of quantitative assessment of postpartum blood loss and institutional changes in clinical practice: an observational study. Int J Obstet Anesth. 2020;42:4-10. https://doi.org/10.1016/j.ijoa.2019.05.006 https://doi.org/10.1016/j.ijoa.2019.05.0... )	2020	United States	Assess the impact of quantification by calibrated field in the estimation of postpartum blood loss compared with colorimetry.	7,781 childbirths 2,568 vaginal childbirths by calibrated field 2,541 by colorimetry 1,243 cesarean sections per calibrated field 1,266 by colorimetry	Observational study Compared to quantification by weighing with calibrated and graduated field and colorimetry	Intervention: quantification with calibrated field Comparator: colorimetry	Quantification in vaginal childbirths (300 ml per field and 258 ml by colorimetry). For cesarean sections, 800 ml per field and 702 ml per colorimetry.	Statistically significant differences were found in the estimation of cases of hemorrhage, being recommended in this study quantification by calibrated field.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Kearney L, Kynn M, Reed R, Davenport L, Young J & Schafer K.(²⁶26 Kearney L, Kynn M, Reed R, Davenport L, Young J, Schafer K. Identifying the risk: a prospective cohort study examining postpartum haemorrhage in a regional Australian health service. BMC Pregnancy Childbirth. 2018;18(1):214. https://doi.org/10.1186/s12884-018-1852-8 https://doi.org/10.1186/s12884-018-1852-... )	2018	Australia	Assess the effectiveness of gravimetry in estimating PPH.	522 vaginal childbirths	Cohort study Exclusion criteria: undergoing cesarean section; multiple pregnancies	Intervention: gravimetry Comparator: VE	Gravimetry made it possible to identify 70% of cases of PPH with a positive correlation (r: 0.88). VE estimated 78% of these cases.	VE was more accurate compared to gravimetry in this study, raising questions about the use of routine gravimetry after uncomplicated childbirths.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Khadilkar SS, Sood A & Ahire P(²⁴24 Khadilkar SS, Sood A, Ahire P. Quantification of peri-partum blood loss: training module and clot conversion factor. J Obstet Gynaecol India. 2016;66(Suppl 1):307-14. https://doi.org/10.1007/s13224-016-0888-9 https://doi.org/10.1007/s13224-016-0888-... )	2016	India	Assess the differences between VE and gravimetry and the effectiveness of simulated training for quantification.	100 vaginal childbirths (36 primiparous and 64 multiparous); 50 cesarean sections (31 primiparous and 17 multiparous); and 50 simulated scenarios VE and gravimetry were compared and, afterwards, the identification of PPH in simulated scenarios	Prospective observational study The following participated as loss evaluators: 20 nurses; eight anesthetists; 20 residents in obstetrics; and six professors of obstetrics	Intervention: training with simulated scenarios and use of VE and gravimetry Comparator: prior knowledge from VE and gravimetry	There was an improvement in the accuracy of losses greater than 500 ml after training. The error rate was 42% to 58% before training, and reduced to 12% to 30% after training. The highest percentage of error was associated with VE, in which the loss was underestimated.	VE was not reliable, and the training had an impact on improving accuracy.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Lertbunnaphong T, Lapthanapat N, Leetheeragul J, Hakularb, P & Ownon A(²⁷27 Lertbunnaphong T, Lapthanapat N, Leetheeragul J, Hakularb P, Ownon A. Postpartum blood loss: visual estimation versus objective quantification with a novel birthing drape. Singapore Med J. 2016;57(6):325-8. https://doi.org/10.11622/smedj.2016107 https://doi.org/10.11622/smedj.2016107... )	2016	Thailand	Compare the effectiveness of VE with gravimetry to determine the volume of postpartum blood loss.	286 women who had vaginal childbirth at term, where patients were their own controls.	Prospective observational study Inclusion criteria: over 18 years old, full-term vaginal childbirth, low-risk pregnancy	Intervention: gravimetry Comparator: VE	There was a significant difference in postpartum blood loss between IV (178.6 ml) and gravimetry (259 ml). There were losses of less than 100 ml - an underestimation of 27.6% of VE. 65.4% of cases of PPH were misdiagnosed by VE (underestimation).	There was an underestimation of losses when using VE. It is suggested to replace the technique with gravimetry.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Lilley G, et al.⁽²⁸28 Lilley G, Burkett-St-Laurent D, Precious E, Bruynseels D, Kaye A, Sanders J, et al. Measurement of blood loss during postpartum haemorrhage. Int J Obstet Anesth. 2015;24(1):8-14. https://doi.org/10.1016/j.ijoa.2014.07.009 https://doi.org/10.1016/j.ijoa.2014.07.0... )	2015	England	Validate the accuracy of quantification by gravimetry through a simulated scenario.	18 simulated scenarios with the participation of 25 obstetricians, 21 anesthetists, 36 nurse midwives and 18 actors, nine anesthesia assistants and eight midwifery students in training Observational: 348 childbirths (gravimetry and Hb drop) - 205 gravimetry <1,500 ml and 143 > 1,500 ml	Methodological study (scenario validation) and observational Only cases classified as PPH were observed.	Intervention: gravimetry Comparator: VE	In scenario validation, the measurement error rate was 34.7% in VE and 4% in gravimetry. The gravimetry used in the observational study showed a positive correlation for the detection of cases of PPH (r = 0.80), and 40% of the women had losses greater than 1,500 ml.	Gravimetry proved to be more accurate for identifying large blood losses. The authors point out that the technique does not require more resources than a baby scale and basic math skills, and can be taught and used routinely in all maternity services.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Lumbreras-Marquez MI, et al.(⁸8 Lumbreras-Marquez MI, Reale SC, Carusi DA, Robinson JN, Scharf N, Fields KG, et al. Introduction of a novel system for quantitating blood loss after vaginal delivery: a retrospective interrupted time series analysis with concurrent control group. Anesth Analg. 2020;130(4):857-68. https://doi.org/10.1213/ANE.0000000000004560 https://doi.org/10.1213/ANE.000000000000... )	2020	United States	Compare PPH detection in vaginal and cesarean childbirths after standardization of quantification of blood loss by colorimetry.	2,468 childbirths: 967 pre-device and 645 post-device vaginal childbirths; 456 pre-device and 418 post-device cesarean sections	Observational study Inclusion criteria: singleton pregnancies Preand post-implementation results of the device were analyzed	Intervention: colorimetry Comparator: gravimetry Reference: preand postpartum Ht level	The mean obtained by the device was 237± 522 ml. By gravimetry, the mean found was 600 ± 556 ml. The difference in means was 349 ml. Device use increased the diagnosis of PPH by 2.49 times.	The device increased the chance of detecting PPH in vaginal childbirths, however there were no statistically significant differences in the preand post-implementation period of device use.	9/11 (confounders and strategies were not anticipated in these cases)
Patel A, et al.(²⁵25 Patel A, Goudar SS, Geller SE, Kodkany BS, Edlavitch SA, Wagh K, et al. Drape estimation vs. visual assessment for estimating postpartum hemorrhage. Int J Gynaecol Obstet. 2006;93(3):220-4. https://doi.org/10.1016/j.ijgo.2006.02.014 https://doi.org/10.1016/j.ijgo.2006.02.0... )	2006	India	Compare VE with the calibrated and graduated field estimate and difference between the calibrated field estimate and colorimetry.	123 vaginal childbirths	Randomized and controlled clinical trial Inclusion criteria: vaginal childbirth 61 patients allocated to VE 62 for the graduated field estimate 10 first from each group, colorimetry being performed	Intervention: calibrated and graduated field Comparator: VE Reference: colorimetry	The mean VE loss was 203 ml (50-950 ml). The mean obtained by the assessment per field was 304 ml (50-975 ml) in the field group, with a mean difference of 101 ml. The mean blood loss with colorimetry was 188 ml (93-286 ml), while the mean blood loss using the drape method was 239 ml (100-350 ml), with a mean difference of 51 ml. A correlation of 0.928 was obtained, indicating accuracy of quantification by field.	The estimation of blood loss by field quantification proved to be more accurate than VE.	11/13 (it was not possible to blind participants and researchers)
Rubens-tein AF, et al.(²¹21 Rubenstein AF, Zamudio S, Douglas C, Sledge S, Thurer RL. Automated quantification of blood loss versus visual estimation in 274 vaginal deliveries. Am J Perinatol. 2021;38(10):1031-5. https://doi.org/10.1055/s-0040-1701507 https://doi.org/10.1055/s-0040-1701507... )	2021	United States	Compare quantification of blood loss from colorimetry with VE.	274 vaginal childbirths, where patients were their own controls	Observational study	Intervention: colorimetry Comparator: VE	The mean obtained by colorimetry was 339 ml (217-515) and significantly higher than the VE, whose mean was 300 ml (200-350). Loss >500 ml was detected in 73 (26.6%) patients compared to 14 (5.1%) patients using VE. PPH (losses greater than 1,000 ml) was recorded in 11 patients (4.0%), while only one patient was diagnosed with PPH by VE.	Quantification by colorimetry proved to be more accurate for the diagnosis of PPH and excessive losses. The study points to the need for objective quantification and suggests further clinical studies using the resource to verify its effectiveness.	8/11 (each participant was their own control, and confounders and strategies were not anticipated in these cases)
Toledo P, McCarthy RJ, Hewlett BJ, Fitzgerald PC, Wong CA (²²22 Toledo P, McCarthy RJ, Hewlett BJ, Fitzgerald PC, Wong CA. The accuracy of blood loss estimation after simulated vaginal delivery. Anesth Analg. 2007;105(6):1736-40. https://doi.org/10.1213/01.ane.0000286233.48111.d8 https://doi.org/10.1213/01.ane.000028623... )	2007	United States	Test the hypothesis that calibrated and graduated fields are more effective than VE.	106 professionals from the obstetric team of a university hospital - obstetric anesthetists and nurses - after undergoing training using simulation - there was no difference between groups	Quasi-experimental study Eight stations were simulated with different amounts of bleeding - 300 to 2000 ml (with and without urine, with and without amniotic fluid). Calibrated and graduated fields and uncalibrated (visual) fields were used.	Intervention: calibrated and graduated fields Comparator: VE without calibrated and graduated field	There was an improvement in VE to assess greater amounts of post-training blood. There was no difference in quantification with calibrated and uncalibrated fields. Calibrated fields showed an error rate of less than 15% and provided better measurement accuracy.	Calibrated and graduated fields showed better accuracy, being a low-cost resource.	8/9 (before-and-after study, no control group)

[1] Corresponding author: Mariana Torreglosa Ruiz , E-mail: marianatorreglosa@hotmail.com

Brasil

Brasil

Quantification of blood loss for the diagnosis of postpartum hemorrhage: a systematic review and meta-analysis

Cuantificación de la pérdida de sangre para el diagnóstico de hemorragia posparto: revisión sistemática y metanálisis

ABSTRACT

Objective:

Methods:

Results:

Conclusion: