Postpartum haemorrhage (PPH) is a major risk factor for maternal morbidity and mortality. PPH has numerous causative factors, which makes its occurrence and severity difficult to predict. Underlying haemostatic imbalances such as consumptive and dilutional coagulopathies may develop during PPH, and can exacerbate bleeding and lead to progression to severe PPH. Monitoring coagulation status in patients with PPH may be crucial for effective haemostatic management, goal-directed therapy, and improved outcomes. However, current PPH management guidelines do not account for the altered baseline coagulation status observed in pregnant patients, and the appropriate transfusion triggers to use in PPH are unknown, due to a lack of high-quality studies specific to this area. In this review, we consider the evidence for the use of standard laboratory-based coagulation tests and point-of-care viscoelastic coagulation monitoring in PPH. Many laboratory-based tests are unsuitable for emergency use due to their long turnaround times, so have limited value for the management of PPH. Emerging evidence suggests that viscoelastic monitoring, using thrombelastography- or thromboelastometry-based tests, may be useful for rapid assessment and for guiding haemostatic therapy during PPH. However, further studies are needed to define the ranges of reference values that should be considered ‘normal’ in this setting. Improving awareness of the correct application and interpretation of viscoelastic coagulation monitoring techniques may be critical in realizing their emergency diagnostic potential.

Haemostatic monitoring during postpartum haemorrhage and implications for management

Disseminated intravascular coagulation in obstetric disorders and its acute haematological management

Background Post-partum haemorrhage (PPH) causes rapidly developing deficiencies in clotting factors and contributes to substantial maternal morbidity and mortality. Rotational thromboelastometry (ROTEM®) is increasingly used as a point of care coagulation monitoring device in patients with massive haemorrhage; however, there are limited data on reference ranges in the peri-partum period. These are required due to the haemostatic changes in pregnancy. Methods In a Dutch multi-centre trial, 161 subjects were included; blood samples were obtained during labour (T1) and within 1 h of delivery (T2). Reference ranges of ROTEM® INTEM, EXTEM, FIBTEM, and APTEM were set and correlation with laboratory results was investigated using the guidelines of the International Federation of Clinical Chemistry. Results Reference ranges were obtained for clotting time (CT), clot formation time (CFT), α-angle, clot firmness at 10 and 20 min (A10, A20), maximum clot firmness (MCF), and maximum lysis (ML). These were comparable from centre to centre, and between T1 and T2. Reference ranges T1: EXTEM: CT 31–63 s, CFT 41–120 s, and MCF 42–78 mm. INTEM: CT 109–225 s, CFT 40–103, and MCF 63–78 mm. FIBTEM: CT 31–79 s and MCF 13–45 mm. APTEM: CT 33–62 s, CFT 42–118, and MCF 61–79 mm. Conclusions Reference values for ROTEM® parameters are reported. The previously published correlation between FIBTEM parameters and plasma fibrinogen levels by the Clauss method is confirmed. Further research is needed to define threshold values for haemostatic therapy in the course of PPH. Clinical trial registration NTR 2515 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2515).

Peri-partum reference ranges for ROTEM(R) thromboelastometry

Globally, postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality. In the current treatment of severe PPH, first-line therapy includes transfusion of packed cells and fresh-frozen plasma in addition to uterotonic medical management and surgical interventions. In persistent PPH, tranexamic acid, fibrinogen, and coagulation factors are often administered. Secondary coagulopathy due to PPH or its treatment is often underestimated and therefore remains untreated, potentially causing progression to even more severe PPH. In most cases, medical and transfusion therapy is not based on the actual coagulation state because conventional laboratory test results are usually not available for 45 to 60 minutes. Thromboelastography and rotational thromboelastometry are point-of-care coagulation tests. A good correlation has been shown between thromboelastometric and conventional coagulation tests, and the use of these in massive bleeding in nonobstetric patients is widely practiced and it has been proven to be cost-effective. As with conventional laboratory tests, there is an influence of fluid dilution on coagulation test results, which is more pronounced with colloid fluids. Fibrinogen seems to play a major role in the course of PPH and can be an early predictor of the severity of PPH. The FIBTEM values (in thromboelastometry, reagent specific for the fibrin polymerization process) decline even more rapidly than fibrinogen levels and can be useful for early guidance of interventions. Data on thromboelastography and thromboelastometry in pregnant women are limited, particularly during the peripartum period and in women with PPH, so more research in this field is needed.

Obstetric hemorrhage and coagulation: an update. Thromboelastography, thromboelastometry, and conventional coagulation tests in the diagnosis and prediction of postpartum hemorrhage.

Placenta previa, placenta accreta, and vasa previa cause significant maternal and perinatal morbidity and mortality. With the increasing incidence of both cesarean delivery and pregnancies using assisted reproductive technology, these 3 conditions are becoming more common. Advances in grayscale and Doppler ultrasound have facilitated prenatal diagnosis of abnormal placentation to allow the development of multidisciplinary management plans to achieve the best outcomes for mother and baby. We present a comprehensive review of the literature on abnormal placentation including an evidence-based approach to diagnosis and management.

Abnormal Placentation: Evidence-Based Diagnosis and Management of Placenta Previa, Placenta Accreta, and Vasa Previa

Purpose of reviewHaemorrhage remains a cause of significant maternal morbidity and mortality. This review summarizes the prevention, management and treatment of obstetric haemorrhage and highlights recent advances and developments.Recent findingsPostpartum haemorrhage is the most common cause of maj

Strategies to manage major obstetric haemorrhage.

Every minute of every day, a woman dies in pregnancy or childbirth. The biggest killer is obstetric haemorrhage, the successful treatment of which is a challenge for both the developed and developing worlds. The presence of an attendant at every birth and access to emergency obstetric care are key to reducing maternal morbidity and mortality in the developing world while resource-rich countries have a rising caesarean section rate with its consequential effect on the incidence of abnormal placentation and its link with peripartum hysterectomy. Management of obstetric haemorrhage involves early recognition, assessment and resuscitation. Various methods are available to try to stop the bleeding – from pharmacological methods to aid uterine contraction (e.g., oxytocinon, ergometrine and prostaglandins) to surgical methods to stem the bleeding (e.g., balloon tamponade, compression sutures or arterial ligation). Interventional radiology can be used if placenta accreta is suspected. Cell salvage has been introduced into obstetrics relatively recently in an attempt to reduce allogeneic transfusion.

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Challenges of major obstetric haemorrhage

Using a cohort study design, we analysed 17 diagnoses and 9 interventions (including critical care admission) as a composite measure of severe maternal morbidity for pregnancies recorded over 14 years in Scotland. There were 762,918 pregnancies, of which 7947 (10 in 1000 pregnancies) recorded 9345 severe maternal morbidity events, 2802 episodes of puerperal sepsis being the most common (30%). Severe maternal morbidity incidence increased from 9 in 1000 pregnancies in 2012 to 17 in 1000 pregnancies in 2018, due in part to puerperal sepsis recording. The odds ratio (95%CI) for severe maternal morbidity was higher for: older women, for instance 1.22 (1.13–1.33) for women aged 35–39 years and 1.44 (1.27–1.63) for women aged > 40 years compared with those aged 25–29 years; obese women, for instance 1.13 (1.06–1.21) for BMI 30–40 kg.m‐2 and 1.32 (1.15–1.51) for BMI > 40 kg.m‐2 compared with BMI 18.5–24.9 kg.m‐2; multiple pregnancy, 2.39 (2.09–2.74); and previous caesarean delivery, 1.52 (1.40–1.65). The median (IQR [range]) hospital stay was 3 (2–5 [1–8]) days with severe maternal morbidity and 2 (1–3 [1–5]) days without. Forty‐one women died during pregnancy or up to 42 days after delivery, representing mortality rates per 100,000 pregnancies of about 365 with severe maternal morbidity and 1.6 without. There were 1449 women admitted to critical care, 807 (58%) for mechanical ventilation or support of at least two organs. We recorded an incidence of severe maternal morbidity higher than previously published, possibly because sepsis was coded inaccurately in our databases. Further research may determine the value of this composite measure of severe maternal morbidity.

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Arlene Wise

Papers

Strategies to manage major obstetric haemorrhage.

Challenges of major obstetric haemorrhage

Severe maternal morbidity in Scotland

P130 Development of glucose-6-phosphate dehydrogenase deficiency guidelines for the obstetric patient

P170 Coagulopathy and placentitis complicating COVID-19 infection in the obstetric population