Elevated prepartum fibrinogen levels are not associated with a reduced risk of postpartum hemorrhage

Hemostatic biomarkers associated with postpartum hemorrhage: a systematic review and meta-analysis

Postpartum hemorrhage (PPH) is a leading cause of maternal morbi-mortality. Although obstetric risk factors are well described, the impact of predelivery hematologic and hemostatic biomarkers remains incompletely understood. In this systematic review, we aimed to summarize the available literature on the association between predelivery hemostatic biomarkers and PPH/severe PPH. Searching MEDLINE, EMBASE, and CENTRAL databases from inception to October 2022, we included observational studies on unselected pregnant women without bleeding disorder reporting on PPH and on predelivery hemostatic biomarkers. Two review authors independently performed title, abstract and full-text screening, upon which quantitative syntheses of studies reporting on the same hemostatic biomarker were conducted, calculating the mean difference (MD) between women with PPH/severe PPH and controls. A search on 18 October 2022 yielded 81 articles fitting our inclusion criteria. The heterogeneity between studies was considerable. With regard to PPH, the estimated average MD in the investigated biomarkers (platelets, fibrinogen, hemoglobin, Ddimer, activated partial thromboplastin time, and prothrombin time) were not statistically significant. Women who developed severe PPH had lower predelivery platelets than controls (MD = -26.0 109/L; 95% confidence interval, -35.8 to -16.1), whereas differences in predelivery fibrinogen concentration (MD = -0.31 g/L; 95% confidence interval, -0.75 to 0.13) and levels of factor XIII or hemoglobin were not statistically significant in women with and without severe PPH. Predelivery platelet counts were, on average, lower in women with severe PPH compared with controls, suggesting the potential usefulness of this biomarker for predicting severe PPH. This trial was registered at the International Prospective Register of Systematic Reviews as CRD42022368075.

Management of severe peri-operative bleeding: Guidelines from the European Society of Anaesthesiology and Intensive Care: Second update 2022

BACKGROUND

Management of peri-operative bleeding is complex and involves multiple assessment tools and strategies to ensure optimal patient care with the goal of reducing morbidity and mortality. These updated guidelines from the European Society of Anaesthesiology and Intensive Care (ESAIC) aim to provide an evidence-based set of recommendations for healthcare professionals to help ensure improved clinical management.

DESIGN

A systematic literature search from 2015 to 2021 of several electronic databases was performed without language restrictions. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used to assess the methodological quality of the included studies and to formulate recommendations. A Delphi methodology was used to prepare a clinical practice guideline.

RESULTS

These searches identified 137 999 articles. All articles were assessed, and the existing 2017 guidelines were revised to incorporate new evidence. Sixteen recommendations derived from the systematic literature search, and four clinical guidances retained from previous ESAIC guidelines were formulated. Using the Delphi process on 253 sentences of guidance, strong consensus (>90% agreement) was achieved in 97% and consensus (75 to 90% agreement) in 3%.

DISCUSSION

Peri-operative bleeding management encompasses the patient's journey from the pre-operative state through the postoperative period. Along this journey, many features of the patient's pre-operative coagulation status, underlying comorbidities, general health and the procedures that they are undergoing need to be taken into account. Due to the many important aspects in peri-operative nontrauma bleeding management, guidance as to how best approach and treat each individual patient are key. Understanding which therapeutic approaches are most valuable at each timepoint can only enhance patient care, ensuring the best outcomes by reducing blood loss and, therefore, overall morbidity and mortality.

CONCLUSION

All healthcare professionals involved in the management of patients at risk for surgical bleeding should be aware of the current therapeutic options and approaches that are available to them. These guidelines aim to provide specific guidance for bleeding management in a variety of clinical situations.

Haemostatic support in postpartum haemorrhage: A review of the literature and expert opinion

Postpartum haemorrhage (PPH) remains the leading cause of pregnancy-related deaths worldwide. Typically, bleeding is controlled by timely obstetric measures in parallel with resuscitation and treatment of coagulopathy. Early recognition of abnormal coagulation is crucial and haemostatic support should be considered simultaneously with other strategies as coagulopathies contribute to the progression to massive haemorrhage. However, there is lack of agreement on important topics in the current guidelines for management of PPH. A clinical definition of PPH is paramount to understand the situation to which the treatment recommendations relate; however, reaching a consensus has previously proven difficult. Traditional definitions are based on volume of blood loss, which is difficult to monitor, can be misleading and leads to treatment delay. A multidisciplinary approach to define PPH considering vital signs, clinical symptoms, coagulation and haemodynamic changes is needed. Moreover, standardised algorithms or massive haemorrhage protocols should be developed to reduce the risk of morbidity and mortality and improve overall clinical outcomes in PPH. If available, point-of-care testing should be used to guide goal-directed haemostatic treatment. Tranexamic acid should be administered as soon as abnormal bleeding is recognised. Fibrinogen concentrate rather than fresh frozen plasma should be administered to restore haemostasis where there is elevated risk of fibrinogen deficiency (e.g., in catastrophic bleeding or in cases of abruption or amniotic fluid embolism) as it is a more concentrated source of fibrinogen. Lastly, organisational considerations are equally as important as clinical interventions in the management of PPH and have the potential to improve patient outcomes.

The role of point of care thromboelastography (TEG) and thromboelastometry (ROTEM) in management of Primary postpartum haemorrhage: A meta-analysis and systematic review

Background

The utility of instantaneous evaluation of coagulation during primary postpartum haemorrhage (PPH) is paramount in the context of empirical blood product transfusion-related risk of dilutional and consumptive coagulopathy and circulatory overload.

Methods

A profound screening of electronic databases till August 15, 2022 was carried out after being enlisted in PROSPERO (CRD42021275514). Randomized control studies, comparative cohort studies, and cross-sectional studies comparing point-of-care viscoelastic test guided blood product transfusion with empirical transfusion in patients with PPH were included.

Results

We retrieved five studies, with a total of 1914 parturient with PPH. Patients receiving transfusion based upon point of care viscoelastic tests had lesser risk of having emergency hysterectomy (Odds ratio (OR) = 0.55, 95% CI 0.32-0.95, I2 = 7%), transfusion-associated circulatory overload (TACO) (OR = 0.03, 95% CI 0.00-0.50), reduced transfusion of fresh frozen plasma (OR = 0.07, 95% CI 0.04-0.14, I2 = 89%), platelets (OR = 0.51, 95% CI 0.28-0.91, I2 = 89%), packed red blood cell transfusion (OR = 0.70, 95% CI 0.55-0.88, I2 = 89%), and had better cost-effective treatment [Mean difference (MD) = -357.5, 95% CI - 567.75 to -147.25, I2 = 93%] than patient received empirical transfusion. However, there was no significant difference in the requirement of ICU admissions (OR = 0.77, 95% CI = 0.46-1.29, I2 = 82%). No mortality was detected across the studies.

Conclusions

Point of care viscoelastic assessment guided transfusion in PPH confederates with reduced morbidity. Nevertheless, more studies on the triggering values for transfusion, long-term survival, and cost-benefit in patients with PPH are warranted to establish its utility.

Predicting postpartum haemorrhage: A systematic review of prognostic models

BACKGROUND

Postpartum haemorrhage (PPH) remains a leading cause of maternal mortality and morbidity worldwide, and the rate is increasing. Using a reliable predictive model could identify those at risk, support management and treatment, and improve maternal outcomes.

AIMS

To systematically identify and appraise existing prognostic models for PPH and ascertain suitability for clinical use.

MATERIALS AND METHODS

MEDLINE, CINAHL, Embase, and the Cochrane Library were searched using combinations of terms and synonyms, including 'postpartum haemorrhage', 'prognostic model', and 'risk factors'. Observational or experimental studies describing a prognostic model for risk of PPH, published in English, were included. The Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modelling Studies checklist informed data extraction and the Prediction Model Risk of Bias Assessment Tool guided analysis.

RESULTS

Sixteen studies met the inclusion criteria after screening 1612 records. All studies were hospital settings from eight different countries. Models were developed for women who experienced vaginal birth (n = 7), caesarean birth (n = 2), any type of birth (n = 2), hypertensive disorders (n = 1) and those with placental abnormalities (n = 4). All studies were at high risk of bias due to use of inappropriate analysis methods or omission of important statistical considerations or suboptimal validation.

CONCLUSIONS

No existing prognostic models for PPH are ready for clinical application. Future research is needed to externally validate existing models and potentially develop a new model that is reliable and applicable to clinical practice.

The role of fibrinogen in postpartum hemorrhage

Postpartum hemorrhage (PPH) is the leading cause of maternal death worldwide (WHO), with almost 60000 deaths annually. Pregnancy is a prothrombotic state with increased levels of several coagulation factors to protect the parturient from bleeding problems during delivery. Fibrinogen has a significant role in coagulation and bleeding. Studies have pointed out that lower fibrinogen levels before delivery, but also at the initiation of PPH, are predictive of major hemorrhage. Early, the goal-directed fibrinogen concentrate therapy might be very useful in a subgroup of patients with serious PPH. This review aims to summarize the current literature on fibrinogen during PPH.

Viscoelastic haemostatic point-of-care assays in the management of postpartum haemorrhage: a narrative review

Viscoelastic haemostatic assays provide rapid testing at the bed-side that identify all phases of haemostasis, from initial fibrin formation to clot lysis. In obstetric patients, altered haemostasis is common as pregnancy is associated with coagulation changes that may contribute to bleeding events such as postpartum haemorrhage, as well as thrombosis events. In this narrative review, we examine the potential clinical utility of viscoelastic haemostatic assays in postpartum haemorrhage and consider the current recommendations for their use in obstetric patients. We discuss the clinical benefits associated with the use of viscoelastic haemostatic assays due to the provision of (near) real-time readouts with a short turnaround, coupled with the identification of coagulation defects such as hypofibrinogenaemia. The use of viscoelastic haemostatic assay-guided algorithms may be beneficial to diagnose coagulopathy, predict postpartum haemorrhage, reduce transfusion requirements and monitor fibrinolysis in women with obstetric haemorrhage. Further studies are required to assess whether viscoelastic haemostatic assay-guided treatment improves clinical outcomes, and to confirm the utility of prepartum viscoelastic haemostatic assay measurements for identifying patients at risk of postpartum haemorrhage.

The association of antenatal D-dimer and fibrinogen with postpartum hemorrhage and intrauterine growth restriction in preeclampsia

BACKGROUND

D-dimer and fibrinogen were verified to be altered in preeclampsia. This study was to evaluate the associations of D-dimer and fibrinogen plasma levels with postpartum hemorrhage or intrauterine growth restriction in preeclamptic women.

METHODS

This was a retrospective study that recruited 278 preeclamptic women with singleton pregnancy from January 2016 to December 2019. Patients were allocated into five groups: mild preeclampsia (mPE) (n=68), mild preeclampsia with postpartum hemorrhage (mPE+PPH) (n=13), severe preeclampsia (sPE) (n=112), severe preeclampsia with postpartum hemorrhage (sPE+PPH) (n=17) and severe preeclampsia with intrauterine growth restriction (sPE+IUGR) (n=68). The antenatal D-dimer and fibrinogen plasma levels were analyzed among the groups. Logistic regression was used to determine the correlation between serum indexes and PPH or IUGR in preeclampsia.

RESULTS

The antenatal D-dimer plasma levels were significantly higher in the sPE+PPH group than that in the sPE group (2.02 μg/ml versus 1.37 μg/ml, P = 0.001), but there was no difference in fibrinogen. Elevated D-dimer was associated with PPH among severe preeclamptic women (adjusted odds ratio (aOR) [95% CI]: 3.093 [1.527-6.264], P = 0.002). No differences in D-dimer and fibrinogen were found between the mPE and mPE+PPH groups or between the sPE and sPE+IUGR groups.

CONCLUSIONS

Elevated antenatal plasma D-dimer level may be associated with postpartum hemorrhage in severe preeclampsia, but not with intrauterine growth restriction. Future prospective clinical trials are needed to investigate the predictive value of D-dimer in postpartum hemorrhage in severe preeclampsia.

Haematological parameters associated with postpartum haemorrhage after vaginal delivery: Results from a French cohort study

BACKGROUND

Immediate postpartum haemorrhage (PPH) is a major, feared and often unpredictable issue. Besides many clinical risk factors, some biological parameters could also be predictive of PPH.

OBJECTIVE

To study simple and easily accessible haematological parameters as potential risk factors for PPH after vaginal delivery.

METHODS

All women who had a vaginal delivery between April 1, 2013 and May 29, 2015 in the maternity ward of Brest University Hospital (France) were included, after oral informed consent obtained. Clinical data were collected by obstetricians or midwives during antenatal care visits, labour and delivery, and recorded by trained research assistants. Haematological variables, including immature platelet fraction, were measured from a blood sample systematically collected at the entrance in the delivery room. PPH, measured with a graduated collector bag, was defined as blood loss of at least 500 ml.

RESULTS

2742 women were included. PPH occurred in 141 (5%) women. Seven clinical factors were independently associated with PPH: pre-eclampsia (OR 5.85, 95%CI 2.02, 16.90), multiple pregnancy (OR 3.28, 95%CI 1.21, 8.91), assisted reproduction (OR 2.75, 95%CI 1.45, 5.20), antepartum bleeding (OR 2.15, 95%CI 1.24,3.73), post-term delivery (OR 1.93, 95%CI 1.17, 3.17), obesity (OR 2.95, 95%CI 1.76, 4.93) and episiotomy (OR 2.51, 95%CI 1.63, 3.74). Three haematological factors were additionally identified as independent risk factors for PPH: platelets < 150 Giga/L (OR 2.98, 95%CI 1.63, 5.46), fibrinogen < 4.5 g/l (OR 1.86, 95%CI 1.21, 2.87) and APTT ratio ≥ 1.1 (OR 2.16, 95%CI 1.31, 3.57). Immature platelet fraction was not associated with PPH.

CONCLUSION

Besides classical clinical risk factors, this study identifies simple haematological parameters as risk factors for PPH.

Can prepartum thromboelastometry-derived parameters and fibrinogen levels really predict postpartum hemorrhage?

BACKGROUND

Decreased postpartum rotational thromboelastometric parameters of coagulation (ROTEM®) and fibrinogen levels have been associated with postpartum hemorrhage (PPH). However, the predictive power of prepartum ROTEM® parameters and fibrinogen levels (Fbgpre) for PPH remains unknown.

METHODS

This prospective observational pilot study included 217 healthy pregnant women. Maximum clot firmness (FIBTEM-MCF), fibrinogen levels and standard coagulation parameters were measured upon admission to the delivery room for labor and within 1 h after vaginal delivery. Blood loss was measured with a calibrated collecting drape during the third stage of labor. PPH was defined as blood loss ≥500 mL. Predictors for bleeding were identified via receiver operating characteristic analyses and bivariate and multivariate regression analyses.

RESULTS

Women with and without PPH did not differ in median FIBTEM-MCF [23 mm (25th percentile 20 mm, 75th percentile 26 mm) vs. 23 mm (19 mm, 26 mm), respectively; P=0.710] or mean Fbgpre (4.57±0.77 g/L vs. 4.45±0.86 g/L, respectively; P=0.431). Blood loss and prepartum coagulation parameters were not correlated (FIBTEM-MCF, rs=-0.055, P=0.431; Fbgpre, rs=-0.017, P=0.810). The areas under the curves (predictive power for PPH) for FIBTEM-MCF and Fbgpre and were 0.52 (0.41-0.64, P=0.699) and 0.53 [95% confidence interval (95% CI) 0.40-0.65, P=0.644], respectively. Neither FIBTEM-MCF nor Fbgpre was associated with PPH. However, primiparity [odds ratio (OR) 4.27, 95% CI 1.32-13.80, P=0.015) and urgent cesarean section (2.77, 1.00-7.67, P=0.050) were independent predictors of PPH.

CONCLUSIONS

ROTEM® parameters, Fbgpre and postpartum blood loss were not associated, nor did these factors predict PPH. Sufficiently powered prospective studies are needed to confirm these results.

Interventional Algorithms for the Control of Coagulopathic Bleeding in Surgical, Trauma, and Postpartum Settings: Recommendations From the Share Network Group

Several clinical settings are associated with specific coagulopathies that predispose to uncontrolled bleeding. With the growing concern about the need for optimizing transfusion practices and improving treatment of the bleeding patient, a group of 9 Portuguese specialists (Share Network Group) was created to discuss and develop algorithms for the clinical evaluation and control of coagulopathic bleeding in the following perioperative clinical settings: surgery, trauma, and postpartum hemorrhage. The 3 algorithms developed by the group were presented at the VIII National Congress of the Associação Portuguesa de Imuno-hemoterapia in October 2013. They aim to provide a structured approach for clinicians to rapidly diagnose the status of coagulopathy in order to achieve an earlier and more effective bleeding control, reduce transfusion requirements, and improve patient outcomes. The group highlights the importance of communication between different specialties involved in the care of bleeding patients in order to achieve better results.

Treatment of Postpartum Hemorrhage With Blood Products in a Tertiary Hospital: Outcomes and Predictive Factors Associated With Severe Hemorrhage

Postpartum hemorrhage (PPH) remains a leading cause of maternal mortality and morbidity worldwide. This retrospective observational study describes patient characteristics and hemostatic therapies administered to 352 parturients experiencing PPH and analyzes risk factors for developing severe PPH. During the study period, bleeding was controlled in all cases and 99.4% survived. The majority (98%) of patients received packed red blood cells. The most frequent hemostatic therapies administered were fibrinogen concentrate (56%), fresh frozen plasma (49%), and platelets (30%). A total of 124 (35%) women experienced severe PPH. Significant independent predictors for evolution to severe PPH were age, obstetric comorbidity, and plasma fibrinogen concentration. The latter was based on records from 267 (76%) patients. Plasma fibrinogen concentration before labor was the only modifiable prepartum risk factor independently associated with severe PPH, indicating that fibrinogen monitoring is warranted in these patients.

Evaluation and management of postpartum hemorrhage: consensus from an international expert panel

BACKGROUND

Postpartum hemorrhage (PPH) remains one of the leading causes of maternal morbidity and mortality worldwide, although the lack of a precise definition precludes accurate data of the absolute prevalence of PPH.

STUDY DESIGN AND METHODS

An international expert panel in obstetrics, gynecology, hematology, transfusion, and anesthesiology undertook a comprehensive review of the literature. At a meeting in November 2011, the panel agreed on a definition of severe PPH that would identify those women who were at a high risk of adverse clinical outcomes.

RESULTS

The panel agreed on the following definition for severe persistent (ongoing) PPH: "Active bleeding >1000 mL within the 24 hours following birth that continues despite the use of initial measures including first-line uterotonic agents and uterine massage." A treatment algorithm for severe persistent PPH was subsequently developed. Initial evaluations include measurement of blood loss and clinical assessments of PPH severity. Coagulation screens should be performed as soon as persistent (ongoing) PPH is diagnosed, to guide subsequent therapy. If initial measures fail to stop bleeding and uterine atony persists, second- and third-line (if required) interventions should be instated. These include mechanical or surgical maneuvers, i.e., intrauterine balloon tamponade or hemostatic brace sutures with hysterectomy as the final surgical option for uncontrollable PPH. Pharmacologic options include hemostatic agents (tranexamic acid), with timely transfusion of blood and plasma products playing an important role in persistent and severe PPH.

CONCLUSION

Early, aggressive, and coordinated intervention by health care professionals is critical in minimizing blood loss to ensure optimal clinical outcomes in management of women with severe, persistent PPH.