Nationwide confidential enquiries into maternal deaths because of obstetric hemorrhage in the Netherlands between 2006 and 2019

Introduction: Obstetric hemorrhage-related deaths are rare in high income countries. Yet, with increasing incidences of obstetric hemorrhage in these countries, it is of utmost importance to learn lessons from each obstetric hemorrhage-related death to improve maternity care. Our objective was to calculate the obstetric hemorrhage-related maternal mortality ratio (MMR), assess causes of obstetric hemorrhage-related deaths, and identify lessons learned. Material and methods: Nationwide mixed-methods prospective case-series with confidential enquiries into maternal deaths due to obstetric hemorrhage in the Netherlands from January 1, 2006 to December 31, 2019. Results: The obstetric hemorrhage-related MMR in the Netherlands in 2006–2019 was 0.7 per 100 000 livebirths and was not statistically significantly different compared with the previous MMR of 1.0 per 100 000 livebirths in 1993–2005 (odds ratio 0.70, 95% confidence interval 0.38–1.30). Leading underlying cause of hemorrhage was retained placenta. Early recognition of persistent bleeding, prompt involvement of a senior clinician and timely management tailored to the cause of hemorrhage with attention to coagulopathy were prominent lessons learned. Also, timely recourse to surgical interventions, including hysterectomy, in case other management options fail to stop bleeding came up as an important lesson in several obstetric hemorrhage-related deaths. Conclusions: The obstetric hemorrhage-related MMR in the Netherlands in 2006–2019 has not substantially changed compared to the MMR of the previous enquiry in 1993–2005. Although obstetric hemorrhage is commonly encountered by maternity care professionals, it is important to remain vigilant for possible adverse maternal outcomes and act upon an ongoing bleeding following birth in a more timely and adequate manner. Our confidential enquiries still led to important lessons learned with clinical advice to professionals as how to improve maternity care and avoid maternal deaths. Drawing lessons from maternal deaths should remain a qualitative and moral imperative

Women receiving massive transfusion due to postpartum hemorrhage: A comparison over time between two nationwide cohort studies

Introduction: Incidence of massive transfusion after birth was high in the Netherlands between 2004 and 2006 compared with other high-income countries. This study investigated incidence, causes, management and outcome of women receiving massive transfusion due to postpartum hemorrhage in the Netherlands in more recent years. Material and methods: Data for all pregnant women who received eight or more units of packed red blood cells from a gestational age of 20 weeks and within the first 24 hours after childbirth, during 2011 and 2012, were obtained from a nationwide retrospective cohort study, including 61 hospitals with a maternity unit in the Netherlands. Results: Incidence of massive transfusion due to postpartum hemorrhage decreased to 65 per 100 000 births (95% CI 56-75) between 2011 and 2012, from 91 per 100 000 births (95% CI 81-101) between 2004 and 2006, while median blood loss increased from 4500 mL (interquartile range 3250-6000) to 6000 mL (interquartile range 4500-8000). Uterine atony remained the leading cause of hemorrhage. Thirty percent (53/176) underwent peripartum hysterectomy between 2011 and 2012, compared with 25% (83/327) between 2004 and 2006. Case fatality rate for women who received massive transfusion due to postpartum hemorrhage was 2.3% (4/176) between 2011 and 2012, compared with 0.9% (3/327) between 2004 and 2006. Conclusions: The incidence of postpartum hemorrhage with massive transfusion decreased in the Netherlands between both time frames, but remained an important cause of maternal mortality and morbidity, including peripartum hysterectomy. National surveillance of maternal morbidity and mortality due to postpartum hemorrhage through an improved and continuous registration with confidential enquiries may lead to the identification of clear improvements of maternal care

Comparison of outcome between intrauterine balloon tamponade and uterine artery embolization in the management of persistent postpartum hemorrhage: A propensity score-matched cohort study

Introduction: The aim of this study was to compare the outcomes of women who were initially managed by intrauterine balloon tamponade or uterine artery embolization because of persistent postpartum hemorrhage demanding an immediate intervention to control bleeding. Material and methods: Propensity score-matched cohort study including women who had intrauterine balloon tamponade or uterine artery embolization as initial management strategy to control persistent postpartum hemorrhage, that is, refractory to first-line therapy combined with at least one uterotonic agent. The primary outcome measure was a composite of peripartum hysterectomy and/or maternal mortality. Secondary outcomes measures were total volume of blood loss and total number of packed red blood cells transfused. Results: Our 1:1 propensity score-matched cohort comprised of 50 women who had intrauterine balloon tamponade and 50 women who underwent uterine artery embolization at a blood loss between 1000 and 7000 mL. There was no statistically significant difference in the hysterectomy risk between the two groups (n = 6 in each group, odds ratio [OR] 1.00, 95% confidence interval [CI].30-3.34), in total volume of blood loss (median 4500 mL, interquartile range [IQR] 3600-5400) for balloon vs 4000 mL (IQR 3250-5000) for embolization, P = 0.382) or in total units of packed red blood cells transfused (median 7 (IQR 5-10) for balloon vs 6 [IQR 4-9] for embolization, P = 0.319). Fifteen women (30%) who were initially managed by an intrauterine balloon still underwent uterine artery embolization, of whom one had an embolization-related thrombo-embolic event. Maternal mortality occurred in neither of the intervention groups. Conclusions: No difference in the risk of peripartum hysterectomy and/or maternal death was observed between women who had intrauterine balloon tamponade and women who underwent uterine artery embolization as an initial management for persistent postpartum hemorrhage. Although this study was underpowered to demonstrate equivalence, our study design provides a framework for future research in which intrauterine balloon tamponade may prove to be a suitable intervention of first choice in the management of persistent postpartum hemorrhage

Clinical value of early assessment of hyperfibrinolysis by rotational thromboelastometry during postpartum hemorrhage for the prediction of severity of bleeding: A multicenter prospective cohort study in the Netherlands

Introduction: Coagulopathy may be the result of hyperfibrinolysis and could exacerbate bleeding following childbirth. Timely recognition of hyperfibrinolysis during the earliest stages of postpartum hemorrhage could identify women at risk of more severe blood loss who may benefit from targeted anti-fibrinolytic therapy. Rotational thromboelastometry (ROTEM®) is a point-of-care test that could detect hyperfibrinolysis. The aim of this study was to evaluate whether early assessment of hyperfibrinolysis by ROTEM during postpartum hemorrhage could predict progression to severe postpartum hemorrhage. Material and methods: During a prospective cohort study in the Netherlands among women with postpartum hemorrhage (total blood loss at least 1000 ml within 24 h after childbirth) ROTEM measurements were performed following 800–1500 ml of blood loss. Hyperfibrinolysis was defined as an enzymatic fibrinolysis index (ROTEM EXTEM maximum clot lysis [ML] minus the ROTEM APTEM ML) above 15%. Severe postpartum hemorrhage was defined as a composite end point of total blood loss greater than 2000 ml, transfusion of four or more units of packed cells, and/or need for an invasive intervention. The predictive value of hyperfibrinolysis for progression to severe postpartum hemorrhage was assessed by area under the receiver operating curve (AUC) and positive and negative predictive values. Trial registration: ClinicalTrials.gov (NCT02149472). Results: Of 390 women included, 82 (21%) had severe postpartum hemorrhage. Four (1%) women had thromboelastometric evidence of hyperfibrinolysis, of whom two developed severe postpartum hemorrhage. The AUC for enzymatic fibrinolysis index more than 15% for progression to severe postpartum hemorrhage was 0.47 (95% CI 0.40–0.54). Positive and negative predictive values for this index were 50.0% (95% CI 6.8–93.2) and 79.3% (95% CI 74.9–83.2), respectively. Conclusions: Thromboelastometric evidence of hyperfibrinolysis was rare in women with postpartum hemorrhage when assessed between 800 and 1500 ml of blood loss. The clinical predictive value of viscoelastometric point-of-care testing for hyperfibrinolysis for progression to severe postpartum hemorrhage during early postpartum hemorrhage is limited

Clinical value of early viscoelastometric point‐of‐care testing during postpartum hemorrhage for the prediction of severity of bleeding: A multicenter prospective cohort study in the Netherlands

Introduction: To evaluate rotational fibrin-based thromboelastometry (ROTEM® FIBTEM) with amplitude of clot firmness at 5 min (A5) as an early point-of-care parameter for predicting progression to severe postpartum hemorrhage, and compare its predictive value with that of fibrinogen. Material and methods: Prospective cohort study in the Netherlands including women with 800–1500 ml of blood loss within 24 h following birth. Blood loss was quantitatively measured by weighing blood-soaked items and using a fluid collector bag in the operating room. Both FIBTEM A5 values and fibrinogen concentrations (Clauss method) were measured between 800 and 1500 ml of blood loss. Predictive accuracy of both biomarkers for the progression to severe postpartum hemorrhage was measured by area under the receiver operating curves (AUC). Severe postpartum hemorrhage was defined as a composite endpoint of (1) total blood loss >2000 ml, (2) transfusion of ≥4 packed cells, and/or (3) need for an invasive intervention to cease bleeding. Results: Of the 391 women included, 72 (18%) developed severe postpartum hemorrhage. Median (IQR) volume of blood loss at blood sampling was 1100 ml (1000–1300) with a median (interquartile range [IQR]) fibrinogen concentration of 3.9 g/L (3.4–4.6) and FIBTEM A5 value of 17 mm (13–20). The AUC for progression to severe postpartum hemorrhage was 0.53 (95% confidence interval [CI] 0.46–0.61) for FIBTEM A5 and 0.58 (95% CI 0.50–0.65) for fibrinogen. Positive predictive values for progression to severe postpartum hemorrhage for FIBTEM A5 ≤12 mm was 22.5% (95% CI 14–33) and 50% (95% CI 25–75) for fibrinogen ≤2 g/L. Conclusions: The predictive value of FIBTEM A5 compared to fibrinogen concentrations measured between 800 and 1500 ml of blood loss following childbirth was poor to discriminate between women with and without progression towards severe postpartum hemorrhage

b tagging in DELPHI at LEP

The standard method used for tagging b-hadrons in the DELPHI experiment at the CERN LEP Collider is discussed in detail. The main ingredient of b-tagging is the impact parameters of tracks, which relies mostly on the vertex detector. Additional information, such as the mass of particles associated to a secondary vertex, significantly improves the selection efficiency and the background suppression. The paper describes various discriminating variables used for the tagging and the procedure of their combination. In addition, applications of b-tagging to some physics analyses, which depend crucially on the performance and reliability of b-tagging, are described briefly.Comment: 54 pages, 26 figures, Accepted by Eur. Phys. J.