Management and outcomes of women with low fibrinogen concentration during pregnancy or immediately postpartum: A UK national population-based cohort study.

INTRODUCTION: Pregnant women with a fibrinogen level <2 g/L represent a high-risk group that is associated with severe postpartum hemorrhage and other complications. Women who would qualify for fibrinogen therapy are not yet identified. MATERIAL AND METHODS: A population-based cross-sectional study was conducted using the UK Obstetric Surveillance System between November 2017 and October 2018 in any UK hospital with a consultant-led maternity unit. Any woman pregnant or immediately postpartum with a fibrinogen <2 g/L was included. Our aims were to determine the incidence of fibrinogen <2 g/L in pregnancy, and to describe its causes, management and outcomes. RESULTS: Over the study period 124 women with fibrinogen <2 g/L were identified (1.7 per 10 000 maternities; 95% confidence interval 1.4-2.0 per 10 000 maternities). Less than 5% of cases of low fibrinogen were due to preexisting inherited dysfibrinogenemia or hypofibrinogenemia. Sixty percent of cases were due to postpartum hemorrhage caused by placental abruption, atony, or trauma. Amniotic fluid embolism and placental causes other than abruption (previa, accreta, retention) were associated with the highest estimated blood loss (median 4400 mL) and lowest levels of fibrinogen. Mortality was high with two maternal deaths due to massive postpartum hemorrhage, 27 stillbirths, and two neonatal deaths. CONCLUSIONS: Fibrinogen <2 g/L often, but not exclusively, affected women with postpartum hemorrhage due to placental abruption, atony, or trauma. Other more rare and catastrophic obstetrical events such as amniotic fluid embolism and placenta accreta also led to low levels of fibrinogen. Maternal and perinatal mortality was extremely high in our cohort.

Acute obstetric coagulopathy during postpartum hemorrhage is caused by hyperfibrinolysis and dysfibrinogenemia: an observational cohort study.

BACKGROUND: Postpartum hemorrhage (PPH) may be exacerbated by hemostatic impairment. Information about PPH-associated coagulopathy is limited, often resulting in treatment strategies based on data derived from trauma studies. OBJECTIVES: To investigate hemostatic changes associated with PPH. PATIENTS/METHODS: From a population of 11 279 maternities, 518 (4.6%) women were recruited with PPH ≥ 1000 mL or placental abruption, amniotic fluid embolism, or concealed bleeding. Routine coagulation and viscoelastometric results were collated. Stored plasma samples were used to investigate women with bleeds > 2000 mL or those at increased risk of coagulopathy defined as placenta abruption, amniotic fluid embolism, or need for blood components. Procoagulant factors were assayed and global hemostasis was assessed using thrombin generation. Fibrinolysis was investigated with D-dimer and plasmin/antiplasmin complexes. Dysfibrinogenemia was assessed using the Clauss/antigen ratio. RESULTS: At 1000 mL blood loss, Clauss fibrinogen was ≤2 g/L in 2.4% of women and 6/27 (22.2%) cases of abruption. Women with very large bleeds (>3000 mL) had evidence of a dilutional coagulopathy, although hemostatic impairment was uncommon. A subgroup of 12 women (1.06/1000 maternities) had a distinct coagulopathy characterized by massive fibrinolysis (plasmin/antiplasmin > 40 000 ng/mL), increased D-dimer, hypofibrinogenemia, dysfibrinogenemia, reduced factor V and factor VIII, and increased activated protein C, termed acute obstetric coagulopathy. It was associated with fetal or neonatal death in 50% of cases and increased maternal morbidity. CONCLUSIONS: Clinically significant hemostatic impairment is uncommon during PPH, but a subgroup of women have a distinct and severe coagulopathy characterized by hyperfibrinolysis, low fibrinogen, and dysfibrinogenemia associated with poor fetal outcomes.

The Role of Thromboelastography during the Management of Postpartum Hemorrhage: Background, Evidence, and Practical Application.

Postpartum hemorrhage (PPH) is a common cause of significant maternal morbidity and mortality that can be associated with coagulopathy, especially hypofibrinogenemia. There is interest in point-of-care viscoelastic hemostatic assays (POC-VHA) in PPH because prompt knowledge of coagulation status can aid diagnosis, identify cases of severe coagulopathy, and allow ongoing monitoring during rapid bleeding. The incidence of coagulopathy in most cases of PPH is low because of the procoagulant state of pregnancy, including raised fibrinogen levels of around 4 to 6 g/L. A Clauss fibrinogen of >2 g/L or POC-VHA equivalent has been found to be adequate for hemostasis during PPH. POC-VHA has been used successfully to diagnose hypofibrinogenemia (Clauss fibrinogen of ≤2 g/L) and guide fibrinogen treatment which has reduced bleed size and complications of massive transfusion. There are uncertainties about the use of POC-VHA to direct fresh frozen plasma and platelet administration during PPH. Several POC-VHA algorithms have been used successfully incorporated in the management of many thousands of PPHs and clinicians report that they are easy to use, interpret, and aid decision making. Due to the relative cost of POC-VHA and lack of definitive data on improving outcomes, these devices have not been universally adopted during PPH.

mSep: investigating physiological and immune-metabolic biomarkers in septic and healthy pregnant women to predict feto-maternal immune health - a prospective observational cohort study protocol.

INTRODUCTION: Maternal sepsis remains a leading cause of death in pregnancy. Physiological adaptations to pregnancy obscure early signs of sepsis and can result in delays in recognition and treatment. Identifying biomarkers that can reliably diagnose sepsis will reduce morbidity and mortality and antibiotic overuse. We have previously identified an immune-metabolic biomarker network comprising three pathways with a >99% accuracy for detecting bacterial neonatal sepsis. In this prospective study, we will describe physiological parameters and novel biomarkers in two cohorts-healthy pregnant women and pregnant women with suspected sepsis-with the aim of mapping pathophysiological drivers and evaluating predictive biomarkers for diagnosing maternal sepsis. METHODS AND ANALYSIS: Women aged over 18 with an ultrasound-confirmed pregnancy will be recruited to a pilot and two main study cohorts. The pilot will involve blood sample collection from 30 pregnant women undergoing an elective caesarean section. Cohort A will follow 100 healthy pregnant women throughout their pregnancy journey, with collection of blood samples from participants at routine time points in their pregnancy: week 12 'booking', week 28 and during labour. Cohort B will follow 100 pregnant women who present with suspected sepsis in pregnancy or labour and will have at least two blood samples taken during their care pathway. Study blood samples will be collected during routine clinical blood sampling. Detailed medical history and physiological parameters at the time of blood sampling will be recorded, along with the results of routine biochemical tests, including C reactive protein, lactate and white blood cell count. In addition, study blood samples will be processed and analysed for transcriptomic, lipidomic and metabolomic analyses and both qualitative and functional immunophenotyping. ETHICS AND DISSEMINATION: Ethical approval has been obtained from the Wales Research Ethics Committee 2 (SPON1752-19, 30 October 2019). TRIAL REGISTRATION NUMBER: NCT05023954.

What is the Economic Cost of Providing an All Wales Postpartum Haemorrhage Quality Improvement Initiative (OBS Cymru)? A Cost-Consequences Comparison with Standard Care.

BACKGROUND AND OBJECTIVE: A postpartum haemorrhage quality improvement initiative (the Obstetric Bleeding Strategy for Wales [OBS Cymru]), including about 60,000 maternities, was adopted across Wales (2017-2018). We performed a cost-consequences analysis to inform ongoing provision and wider uptake. METHODS: Analysis was based on primary data from the All Wales postpartum haemorrhage database, with a UK National Health Services perspective, a time horizon from delivery until hospital discharge and no discounting. Costs were based on UK published sources with viscoelastic haemostatic assay costs provided by the OBS Cymru national team. Mean costs per eligible patient (postpartum haemorrhage > 1000 mL) were calculated for OBS Cymru, using the early implementation period as a comparator. Modelling allowed comparisons of three scenarios (two predefined and one post hoc) and implementation in different sizes of maternity unit. RESULTS: All analyses demonstrated consistent savings in blood products, critical care and haematology time, and also a reduced occurrence of massive postpartum haemorrhage (> 2500 mL). Incremental postnatal length of stay varied between scenarios, substantially impacting on total costs. Mean incremental cost of OBS Cymru, compared with standard care, across Wales was £18.41 per patient (postpartum haemorrhage > 1000 mL) or - £10.66 if the length of stay was excluded. Modelling a maternity unit of 5000 births per annum, OBS Cymru incurred an incremental cost of £9.53 per patient with postpartum haemorrhage > 1000 mL. CONCLUSIONS: OBS Cymru reduces the occurrence of massive postpartum haemorrhage, need for transfusions, quantity of blood products and intensive care. In medium-to-large maternity units (>3000 maternities per annum), the OBS Cymru intervention approaches cost neutrality compared to standard care.

Reduction in massive postpartum haemorrhage and red blood cell transfusion during a national quality improvement project, Obstetric Bleeding Strategy for Wales, OBS Cymru: an observational study.

BACKGROUND: Postpartum haemorrhage (PPH) is a major cause of maternal morbidity and mortality and its incidence is increasing in many countries despite management guidelines. A national quality improvement programme called the Obstetric Bleeding Strategy for Wales (OBS Cymru) was introduced in all obstetric units in Wales. The aim was to reduce moderate PPH (1000 mL) progressing to massive PPH (> 2500 mL) and the need for red cell transfusion. METHODS: A PPH care bundle was introduced into all 12 obstetric units in Wales included all women giving birth in 2017 and 2018 (n = 61,094). The care bundle prompted: universal risk assessment, quantitative measurement of blood loss after all deliveries (as opposed to visual estimation), structured escalation to senior clinicians and point-of-care viscoelastometric-guided early fibrinogen replacement. Data were submitted by each obstetric unit to a national database. Outcome measures were incidence of massive PPH (> 2500 mL) and red cell transfusion. Analysis was performed using linear regression of the all Wales monthly data. RESULTS: Uptake of the intervention was good: quantitative blood loss measurement and risk assessment increased to 98.1 and 64.5% of all PPH > 1000 mL, whilst ROTEM use for PPH > 1500 mL increased to 68.2%. Massive PPH decreased by 1.10 (95% CI 0.28 to 1.92) per 1000 maternities per year (P = 0.011). Fewer women progressed from moderate to massive PPH in the last 6 months, 74/1490 (5.0%), than in the first 6 months, 97/1386 (7.0%), (P = 0.021). Units of red cells transfused decreased by 7.4 (95% CI 1.6 to 13.2) per 1000 maternities per year (P = 0.015). Red cells were transfused to 350/15204 (2.3%) and 268/15150 (1.8%) (P = 0.001) in the first and last 6 months, respectively. There was no increase in the number of women with lowest haemoglobin below 80 g/L during this time period. Infusions of fresh frozen plasma fell and there was no increase in the number of women with haemostatic impairment. CONCLUSIONS: The OBS Cymru care bundle was feasible to implement and associated with progressive, clinically significant improvements in outcomes for PPH across Wales. It is applicable across obstetric units of widely varying size, complexity and staff mixes.

Incidence of postpartum haemorrhage defined by quantitative blood loss measurement: a national cohort.

BACKGROUND: Visual estimation of blood loss following delivery often under-reports actual bleed volume. To improve accuracy, quantitative blood loss measurement was introduced for all births in the 12 hospitals providing maternity care in Wales. This intervention was incorporated into a quality improvement programme (Obstetric Bleeding Strategy for Wales, OBS Cymru). We report the incidence of postpartum haemorrhage in Wales over a 1-year period using quantitative measurement. METHODS: This prospective, consecutive cohort included all 31,341 women giving birth in Wales in 2017. Standardised training was cascaded to maternity staff in all 12 hospitals in Wales. The training comprised mock-scenarios, a video and team drills. Uptake of quantitative blood loss measurement was audited at each centre. Data on postpartum haemorrhage of > 1000 mL were collected and analysed according to mode of delivery. Data on blood loss for all maternities was from the NHS Wales Informatics Service. RESULTS: Biannual audit data demonstrated an increase in quantitative measurement from 52.1 to 87.8% (P < 0.001). The incidence (95% confidence intervals, CI) of postpartum haemorrhage of > 1000 mL, > 1500 mL and > 2000 mL was 8.6% (8.3 to 8.9), 3.3% (3.1 to 3.5) and 1.3% (1.2 to 1.4), respectively compared to 5%, 2% and 0.8% in the year before OBS Cymru. The incidence (95% CI) of bleeds of > 1000 mL was similar across the 12 hospitals despite widely varied size, staffing levels and case mix, median (25th to 75th centile) 8.6% (7.8-9.6). The incidence of PPH varied with mode of delivery and was mean (95% CI) 4.9% (4.6-5.2) for unassisted vaginal deliveries, 18.4 (17.1-19.8) for instrumental vaginal deliveries, 8.5 (7.7-9.4) for elective caesarean section and 19.8 (18.6-21.0) for non-elective caesarean sections. CONCLUSIONS: Quantitative measurement of blood loss is feasible in all hospitals providing maternity care and is associated with detection of higher rates of postpartum haemorrhage. These results have implications for the definition of abnormal blood loss after childbirth and for management and research of postpartum haemorrhage.

Designing and implementing an all Wales postpartum haemorrhage quality improvement project: OBS Cymru (the Obstetric Bleeding Strategy for Wales).

BACKGROUND: Postpartum haemorrhage (PPH) contributes to substantial maternal morbidity. Research into PPH has led to improvements in care which have been incorporated into the Obstetric Bleeding Strategy for Wales. INTERVENTION: A national quality improvement team supported local teams in implementing multiple interventions including risk assessment, objective measurement of blood loss, multiprofessional assessment (at the bedside at 1000 mL blood loss) and point-of-care (POC) testing of coagulation to guide blood product resuscitation during PPH. The project was rolled out to all 12 obstetric units in 2017. The interventions were reinforced by an All Wales Guideline, PPH proforma and standardised training. A national database, biannual audits, and patient and staff surveys reported process and outcome measures. RESULTS: Process measures: during 2017, there was an increase in the percentage of maternities with documented risk assessment (0%-76%), objective measurement of blood loss (52%-88%) and POC testing for coagulation for PPH ≥1500 mL (38%-59%). Maternity staff survey indicated that 94% were aware of the project and 87% stated that it had changed their unit's management of PPH. Interim outcome measures: the incidence (95% CI) of PPH ≥2500 mL per 1000 maternities in 2017 was 6.03 (5.23-6.95). The annual number of women receiving any red blood cell transfusion, level 3 intensive care admission and hysterectomy for PPH was 19.7 (18.2 to 21.3), 0.702 (0.464 to 1.06) and 0.255 (0.129 to 0.504) per 1000 maternities, respectively. CONCLUSIONS: A high level of project awareness across Welsh maternity units has been achieved. Measurement of blood loss was reported to be the most important early change in practice, while PPH documentation and POC testing continue to be embedded. Combining qualitative and quantitative measures to inform implementation has improved project delivery and allowed teams to adapt to local contexts.

Falling caesarean section rate and improving intra-partum outcomes: a prospective cohort study.

OBJECTIVE: To evaluate caesarean section (CS) rates and moderate to severe hypoxaemic ischaemic encephalopathy (HIE) rates with other core intra-partum outcomes following reconfiguration of maternity services in Cardiff, South Wales, UK. DESIGN: Cohort study of births from 2006 to 2015. SETTINGS: A University tertiary referral centre for foetal and maternal medicine with 6000 births/year, University Hospital of Wales, United Kingdom. METHOD: Data relating to births from 1 January 2006 to 31 December 2015 were extracted from the computerized maternity database on a yearly basis. Case notes of all mothers and babies for the same duration were hand searched for documentation of HIE. HIE data was also collected prospectively by neonatologist (SC) and obstetrician (PA). MAIN OUTCOME MEASURES: Incidence of caesarean section births, babies with moderate to severe HIE, instrumental vaginal births, obstetric anal sphincter injuries (OASIS) associated with instrumental delivery, and major post-partum haemorrhage (MPPH) of 2500 mL or more. RESULTS: During this 10-year period, a downward trend in emergency CS rate was seen from 15.6% in 2006 to 10.5% in 2015, reducing total CS rate from 25.5% in 2006 to 21.2% in 2015. A downward trend in the incidence of moderate and severe HIE was seen over the same period. There was an increase in operative vaginal births (OVB) from 12.8% to 15%. The rate of spontaneous vaginal births (SVB) remained stable. The incidence of OASIS remained constant and MPPH rate has fallen. CONCLUSIONS: Following amalgamation of two medium sized obstetric units and the opening of a Midwifery Led Unit (MLU), core intrapartum outcomes have improved. Contributing factors are the introduction of regular multidisciplinary training with enhanced team working, compulsory education for obstetricians and midwives on cardiotocograph (CTG) interpretation, increased consultant presence on delivery suite, robust risk management systems and broad multidisciplinary agreement on clinical guidelines promoting vaginal birth.

Managing major obstetric haemorrhage: Pharmacotherapy and transfusion.

Major obstetric haemorrhage is a leading cause of maternal mortality. A prescriptive approach to early recognition and management is critical to improving outcomes. Uterine atony is the primary cause of post-partum haemorrhage. First-line prevention and treatment include the administration of uterine tonic agents; other conservative measures include uterine cavity tamponade and uterine compression sutures. Interventional radiology procedures have been used for both prophylaxis and treatment, but a hysterectomy may be necessary if conservative measures fail. Assessment of anaemia and coagulation status is an important aspect of the management of haemorrhage. Hypofibrinogenaemia is a predictor of severe haemorrhage. Early and empiric use of fixed transfusion red blood cell:plasma:platelet ratios is controversial and may not be justified for all causes of haemorrhage. Cell salvage may be used safely in obstetric haemorrhage. Goal-directed therapy using point-of-care testing (e.g. thromboelastography) has not been well studied but holds promise for individualising resuscitation measures.

Commentary on Reconstituting Fibrinogen Concentrate to Maintain Blinding in a Double-blind, Randomized Trial in an Emergency Setting.

BACKGROUND: The gold standard of trial design is the double-blind, placebo-controlled, randomized trial. Intravenous medication, which needs reconstitution by the attending clinician in an emergency situation, can be challenging to incorporate into a suitably blinded study. DISCUSSION: We have developed a method of blindly reconstituting and administering fibrinogen concentrate (presented as a lyophilized powder), where the placebo is normal saline. Fibrinogen concentrate is increasingly being used early in the treatment of major hemorrhage. Our methodology was designed for a multicenter study investigating the role of fibrinogen concentrate in the treatment of the coagulopathy associated with major obstetric hemorrhage. The method has been verified by a stand-alone pharmaceutical manufacturing unit with an investigational medicinal products license, and to date has successfully been applied 45 times in four study centers. There have been no difficulties in reconstitution and no related adverse events reported. CONCLUSION: We feel our method is simple to perform and maintains blinding throughout, making it potentially suitable for use in other trials conducted in psychologically high-pressure environments. Although fibrinogen concentrate was the focus of our study, it is likely that the method is applicable to other lyophilized medication with limited shelf life (e.g., antibiotics).

The haematological features and transfusion management of women who required massive transfusion for major obstetric haemorrhage in the UK: a population based study.

Understanding the coagulopathy of major-obstetric-haemorrhage (MOH) that leads to massive-transfusion (MT) is fundamental to improving outcomes. This study reports on the haematological features and transfusion management of women experiencing MT [defined as transfusion of ≥8 units of red blood cells (RBC) within 24 h of delivery]. One hundred and eighty-one cases [median (interquartile range; IQR) age 33 years (29-36)] were identified from all UK hospitals, using the UK Obstetric Surveillance System between July 2012 and June 2013. The median (IQR) estimated blood loss was 6 l (4·5-8). At presentation, the median platelet count was lowest for placenta accreta, compared with other causes, while the median prothrombin time and fibrinogen were <1·5 × mean normal and <3 g/l, respectively for all aetiologies. Median platelet count and fibrinogen fell to <75 × 10(9) /l and <2 g/l, respectively for all causes during bleeding, except for trauma. The median (IQR) units of RBC, fresh-frozen-plasma (FFP) and cryoprecipitate transfused were 10 (8-14), 6 (4-8) and 2 (2-4), respectively. The median time from the onset of bleeding to delivery of the first RBC unit was significantly shorter for women who delivered via elective caesarean section, compared with others. The coagulopathy of MT during MOH differs significantly depending on its cause, suggesting that more targeted transfusion strategies are required.

Fibrinogen concentrate versus placebo for treatment of postpartum haemorrhage: study protocol for a randomised controlled trial.

BACKGROUND: Postpartum haemorrhage (PPH) is a major cause of maternal morbidity. Bleeding is caused by a combination of physical causes, such as failure of the uterus to contract or operations, and is made worse by impairment of the blood clotting system. A number of studies have shown that low levels of the blood clotting factor fibrinogen are associated with progression of bleeding, the need for invasive interventions and transfusions of red blood cells and fresh frozen plasma (FFP). This trial will investigate whether early infusion of fibrinogen concentrate during a major PPH, with the aim of correcting a low fibrinogen to a level that is normal for delivery, based on the Fibtem test, reduces the total number of allogeneic blood products (red blood cells, FFP, cryoprecipitate and platelets) transfused after study medication until discharge, compared to placebo. METHODS/DESIGN: This is a prospective, randomised, double-blind placebo controlled trial. Women will enter an observational phase and if their Fibtem levels fall they will be randomised in the interventional phase. A total of 60 women will be randomised and women are eligible for the trial if they meet all of the following inclusion criteria: age 18 years or over, gestation ≥24 + 0 weeks, haemorrhage of about 1500 ml and on-going bleeding without another complication or haemorrhage of about 1000 ml and caesarean section/uterine atony/placental abruption/placenta praevia/cardiovascular instability or microvascular oozing. Participants with a Fibtem A5 < 16 mm will be randomly allocated to receive either a bolus infusion of fibrinogen concentrate or placebo (isotonic saline). The dose of fibrinogen concentrate or placebo will be calculated based on the woman's ideal body weight for height and the measured Fibtem A5 with the aim of increasing the Fibtem A5 to 23 mm. DISCUSSION: The trial aims to provide evidence on the efficacy and safety of fibrinogen concentrate during acute bleeding in an obstetric setting. TRIAL REGISTRATION: ISRCTN ref: ISRCTN46295339 (01.07.2013); EudraCT: 2012-005511-11 (28.11.2012), UKCRN ref: 13940.

The white cell count in pregnancy and labour: a reference range.

OBJECTIVE: The white cell count (WCC) can be raised in pregnancy, but there is no published data-set to support a normal range. This study aimed to develop one. METHODS: The WCC of 500 consecutive labouring women at term receiving regional anaesthesia and 500 consecutive women delivered at term by elective caesarean section were retrieved from an electronic database. RESULTS: The mean and derived reference range at term with no labour was 8.9 × 10(9)/L (5-13 10(9)/L) and for the labouring group was 15.3 × 10(9)/L (5.3-25.3 × 10(9)/L). Fifteen women had a WCC > 25.3 × 10(9)/L (range 25.4-33.5 × 10(9)/L) not associated with severe sepsis. CONCLUSION: Two distinct normal ranges have been established to aid clinicians recognise normal and abnormal results.

Fibrin-based clot formation as an early and rapid biomarker for progression of postpartum hemorrhage: a prospective study.

This prospective, observational study investigated the utility of Fibtem A5 and Clauss fibrinogen as predictors of progression of postpartum hemorrhage (PPH). A consecutive cohort of 356 women experiencing 1000 to 1500 mL PPH was recruited. Fibtem and fibrinogen were measured and subsequent transfusions, invasive procedures, and bleed volume recorded. Women progressing to 8 U blood products (red blood cells [RBCs] + fresh frozen plasma [FFP] + platelets) had a median (interquartile range) fibrinogen and Fibtem A5 of 2.1 (1.8-3.4) g/L and 12 (7-17) mm, respectively, compared with 3.9 (3.2-4.5) and 19 (17-23) for those not progressing. On multivariate analysis, Fibtem was an independent predictor for progression to bleeds >2500 mL (95% confidence interval [CI], 0.85 [0.77-0.95]). Receiver operating characteristic area under the curve (95% CI) for progression to RBC transfusion was 0.67 (0.60-0.74) for fibrinogen and 0.61 (0.54-0.68) for Fibtem, and progression to >2500 mL was 0.71 (0.61-0.81) and 0.75 (0.66-0.85) for fibrinogen and Fibtem, respectively. Fibtem A5 <10 mm was associated with more prolonged bleeds (median [95% CI], 127 [44-210] compared with 65 [59-71] minutes; P = .018) and longer stay in the high-dependency unit (23.5 [18.4-28.5] compared with 10.8 [9.7-11.8] hours). Fibtem is a rapidly available early biomarker for progression of PPH.