Maternal and pregnancy characteristics affect plasma fibrin monomer complexes and D-dimer reference ranges for venous thromboembolism in pregnancy

Establishing Expectancy Values for Fibrin Monomer in Uncomplicated Pregnancy

Background  During pregnancy, a physiological increase of molecular activation markers (MAM) of hemostasis such as prothrombin fragments 1 + 2, thrombin-antithrombin complex, and D-dimers (DD) occurs. Therefore, monitoring MAM levels during pregnancy to evaluate the risk of venous thromboembolism (VTE) may be unreliable; nevertheless, DD analysis in pregnancy is widely performed. In contrast to DD, fibrin monomer (FM) levels have been reported to remain stable during pregnancy. Objectives  The main aim of this study was to define the expected range for FM levels in pregnant outpatients. In addition, we examined the impact of the individual VTE risk, as calculated by the pregnancy risk score of the Royal College of Obstetricians and Gynaecologists (RCOG), as well as that of antithrombotic treatment on FM levels. Methods  A total of 342 pregnant women seen at our hemostasis unit were included throughout 350 pregnancies in 899 samples. Results  Low-risk thrombophilia, but not the RCOG score itself, was found to influence all MAM levels, whereas antithrombotic treatment had only an impact on DD. For FM, a reference range could be calculated irrespective of the pregnancy term, in contrast to other MAMs, which fluctuated throughout pregnancy. Conclusions  Our findings suggest a stronger impact of inherited thrombophilia on hemostasis activity during pregnancy as compared with acquired or other predisposing thrombophilic risk factors. FM levels showed a marginal increase during pregnancy in contrast to other MAM and remain a potential candidate to improve the laboratory assessment of VTE risk during pregnancy. Further prospective studies in pregnant patients with suspicion of VTE are needed.

Nonovert disseminated intravascular coagulation (DIC) in pregnancy: a new scoring system for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion

BACKGROUND

Nonovert disseminated intravascular coagulation (DIC) is a subclinical hemostatic dysfunction that has not yet reached the decompensation stage. The detection of pregnant patients at this stage may assist in the identification of those who will develop severe obstetrical hemorrhage, as it is one of the leading causes for preventable maternal mortality. Currently, nonovert DIC is diagnosed by a scoring system based on nonpregnant patients, originally generated by the International Society on Thrombosis and Hemostasis (ISTH), which does not address the physiologic changes of the hemostatic system during pregnancy.

OBJECTIVES

(1) To develop a pregnancy-specific nonovert DIC score, (2) to determine the diagnostic performance of this score in detecting women at risk for obstetrical hemorrhage requiring blood product transfusion, and (3) to compare it to the existing ISTH nonovert DIC score.

STUDY DESIGN

This retrospective study has longitudinal and cross-sectional components and includes three steps: (1) characterization of the longitudinal changes in the components of modified ISTH nonovert DIC scores, including these parameters - fibrinogen, antithrombin III, protein C, prothrombin time (PT), platelets, thrombin-antithrombin (TAT) complex, and D-dimer - during gestation in a group of normal pregnancies (n = 50); (2) development of a pregnancy-specific nonovert DIC score in a cross-sectional design of high-risk (n = 152) and control (n = 50) pregnancies, based on the predictive performance of each analyte for the detection of women at risk for obstetrical hemorrhage requiring blood product transfusion and a logistic regression model; and (3) comparison between the diagnostic performance of the pregnancy-specific nonovert DIC score and the modified ISTH nonovert DIC score to detect, upon admission, women who are at increased risk for subsequent development of obstetrical hemorrhage requiring blood product transfusion.

RESULTS

(1) The study cohort included 202 patients, of which 21 (10%) had obstetrical hemorrhage that required blood product transfusion and were considered to have nonovert DIC; (2) using the nonpregnant ISTH nonovert DIC score, 92% of the patients had a D-dimer concentration above the 0.5 mg/L threshold, and only 2% were identified to have a low fibrinogen concentration (<100 mg/dL); thus, this scoring system was unable to identify any of the patients with nonovert DIC based on the suggested cutoff of a score of ≥5; (3) the parameters included in the pregnancy-specific nonovert DIC score were selected based on their contribution to the performance of the model for the prediction of women at risk for obstetrical hemorrhage requiring blood product transfusion; as a result, we excluded the PT difference parameter from the score and the TAT complex concentration was added; and (4) a pregnancy-specific nonovert DIC score of ≥3 had a sensitivity of 71.4% and a specificity of 77.9% to identify patients at risk for obstetrical hemorrhage requiring blood product transfusion.

CONCLUSION

We propose (1) a pregnancy-specific nonovert DIC score adjusted for the physiologic changes in the hemostatic system during gestation; and (2) that the pregnancy-specific nonovert DIC score can be a useful tool for the identification of patients at risk for obstetrical hemorrhage requiring blood product transfusion.

New cut-off point for D-dimer in the diagnosis of pulmonary embolism during pregnancy

Background

Considering that pulmonary embolism (PE) is one of the leading causes of mortality among pregnant women and that the D-dimer level in pregnancy can be highly fluctuating, a new and reliable D-dimer reference value is essential to identifying PE in this group of patients. Hence, the present study aimed to evaluate the diagnostic effect of D-dimer testing in pregnant women with suspected PE.

Methods

This study recruited 100 women with confirmed pregnancy or six weeks after delivery or abortion with suspected PE symptoms. Wells criteria, D-dimer values, and pregnancy trimesters were recorded. Definitive PE results were obtained using multidetector computed tomography (MDCT) or pulmonary ventilation/perfusion scans.

Results

D-dimer cut-off point in PE diagnosis was higher than 1,447 mg/L [sensitivity, 87.5%; specificity, 63.04%; area under the curve (AUC)=0.735; P=0.003]. In addition, the combination of Wells criteria with the D-dimer test indicated that the cut-off points of D-dimer in PE likely and unlikely women were 1,962 and 1,447 mg/L, respectively, and had acceptable and significant diagnostic value in PE detection. In addition, the diagnostic value of D-dimer in pregnancy trimesters was not found to be significant (P>0.05).

Conclusion

The new cut-off points of 1,447 and 1,962 mg/L were determined for D-dimer in pregnant women with likely and unlikely PE, respectively. Moreover, the new cut-off points in the first and second trimesters of pregnancy were 1,701 mg/L and 1,451 mg/L, respectively, which indicated no statistically acceptable diagnostic value.

Impact of specific preclinical variables on coagulation biomarkers in cancer-associated thrombosis

Coagulation biomarkers are being actively studied for their diagnostic and prognostic value in patients with venous thromboembolism and cancer, as well as in the study of pathogenic mechanisms between cancer and thrombosis. For the results of such studies to be accurate and reproducible, attention must be paid to minimize sources of error in all phases of testing. The pre-analytical phase of laboratory testing is known to be fraught with the majority of errors. Coagulation testing is particularly susceptible to conditions during collection, processing, transport and storage of specimens which can lead to clinically significant errors in results. In addition, changes in pre-analytical conditions can impact different biomarkers differently. Therefore, research studies investigating coagulation biomarkers must carefully standardize not just the analytical phase, but also the pre-analytical phase of testing to ensure accuracy and reliability. We briefly review the impact of pre-analytical conditions on coagulation testing in general, and on specific biomarkers in cancer and thrombosis. In addition, we provide recommendations to reduce pre-analytical errors by developing and sharing standard operating procedures that specifically target standardization of methodologies for collecting specimens and measuring current and emerging coagulation biomarkers in cancer studies.

Monitoring of hemostatic parameters for early prediction of first-trimester miscarriage

BACKGROUND

Hypercoagulation starts as early as the first-trimester pregnancy and is a risk factor for thromboembolic events which are associated with miscarriage. Our study aimed to investigate coagulation, platelets, and fibrinolysis parameters alteration amongst trimester-specific normal pregnancy and first-trimester miscarriage patients. We also test the accuracy of haemostatic parameters determination for prediction of first-trimester miscarriage.

METHODS

Retrospective investigation of 50 women whose most recent pregnancy had ended in the first trimester and 54 age-matched consecutive normal pregnancy between 2016 and 2019. Furthermore, 51 non-pregnant, age-matched women were included in parallel to healthy controls. Twelve screening tests for coagulation and platelet parameters were assessed.

RESULTS

We found plasma levels of aPTT, FBG, and TT were significantly prolonged or decreased in miscarriage subjects than the corresponding first phase in normal pregnancies. PT, INR, aPTT, and d-dimer all shift back to normal in miscarriage patients compared with non-pregnant women. Shortened aPTT combined with TT and FBG can predicted the occurrence of first-trimester miscarriage with an AUC of 0.831.

CONCLUSIONS

Routine assessment of aPTT combined with TT and FBG is a low-cost, widely available marker for prediction of first-trimester miscarriage.

Comparison of international societal guidelines for the diagnosis of suspected pulmonary embolism during pregnancy

Pregnancy-associated pulmonary embolism is one of the leading causes of maternal mortality. Diagnosis of pulmonary embolism in pregnancy is challenging, with symptoms of pulmonary embolism mimicking those of pregnancy. Several key components such as clinical prediction tools, risk stratification, laboratory tests, and imaging widely used for diagnosis of pulmonary embolism in the non-pregnant population show limitations for diagnosis in pregnancy. Further, because of the difficulty of studying pregnant patients, high-quality research evaluating the performance of these diagnostic components in pregnancy is scarce. Seven international medical society guidelines present clinical diagnostic pathways for evaluation of pulmonary embolism in pregnancy that show conflicting recommendations on the use of these diagnostic components. This Review assesses all key components of diagnostic clinical pathways recommended by guidelines for evaluation of pulmonary embolism in pregnancy, reviews current evidence, compares the guideline recommendations with respect to each key component, and provides our preferred diagnostic pathway. It provides the guidelines and available data needed for informed decision making to diagnose pulmonary embolism in pregnancy.

Impact of fetal maceration grade on risk of maternal disseminated intravascular coagulation after intrauterine fetal death - A retrospective cohort study

Disseminated intravascular coagulation (DIC) is a life-threatening event that is the endpoint of a pathologically activated cascade leading to excessive consumption of platelets culminating in bleeding. Several diseases are known to be associated with DIC, some of which may also occur during pregnancy or the puerperium. One of the potential risk factors that have been considered as a potential trigger for DIC is the retention of a highly macerated fetus after intrauterine fetal death (IUFD). However, sparse evidence exists on its clinical implication on hemostasis parameters. In this retrospective single-center study, we investigated the role of fetal maceration grades 0-III on the risk of DIC in 91 women following IUFD between gestational weeks (+days) 22 + 0 and 41 + 6 between 2003 and 2017. We calculated the Erez DIC-score after consideration of maternal platelet count (PC), prothrombin time (PT) and fibrinogen (Fib) and correlated the findings with fetal maceration grade. Mean (±SD) age of women was 32.1 ± 6.7 years. Neither maternal hemostasis parameters (PC, PT, Fib), nor the Erez score showed a statistically significant difference between maceration grades 0-III with median values of 1 for all four grades (maceration grade I: range 0 to 27; I: 0 to 51; II: 0 to 52; III: 0 to 39). We therefore conclude, that the pathophysiology of DIC in women after singleton IUFD is unrelated to the degree of fetal maceration.

Maternal and neonatal outcomes among pregnant women with fibromyalgia: a population-based study of 12 million births

PURPOSE

Fibromyalgia (FM) is a rheumatologic disorder marked by chronic, widespread pain and associated comorbid conditions. The purpose of our study was to evaluate the effect of FM on maternal and neonatal outcomes.

METHODS

Using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from 1999 to 2013, we conducted a population-based retrospective cohort study consisting of women who delivered during that period. Logistic regression was used to compare maternal and neonatal outcomes among pregnancies in women with and without FM.

RESULTS

Of 12 584 918 births during the 15-year study period, 7758 (0.06%) were to women with FM with rates increasing over the study period. Women with FM were more commonly older in age, overweight or obese, and users of alcohol, tobacco, and illicit drugs. They were more likely to experience anxiety, depression, and bipolar disorder. Women with FM were at greater risk of gestational diabetes, preterm premature rupture of membranes, and placental abruption. Women with FM more commonly had cesarean deliveries (odds ratios (OR): 1.11, 95% CI: 1.05-1.16) and births complicated by venous thromboembolism (OR: 2.34, 95% CI: 1.91-2.86). Infants of women with FM were more likely to be premature (OR: 1.35, 95% CI: 1.25-1.46) and have intrauterine growth restriction (OR: 1.48, 95% CI: 1.30-1.68).

CONCLUSIONS

The prevalence of FM in pregnancy is rising in the US. FM is a high-risk pregnancy condition associated with adverse maternal and newborn outcomes.

Diagnosis of acute pulmonary embolism

Advances in the management of patients with suspected pulmonary embolism (PE) have improved diagnostic accuracy and made management algorithms safer, easier to use, and well standardized. These diagnostic algorithms are mainly based on the assessment of clinical pretest probability, D-dimer measurement, and imaging tests-predominantly computed tomography pulmonary angiography. These diagnostic algorithms allow safe and cost-effective diagnosis for most patients with suspected PE. In this review, we summarize signs and symptoms of PE, current existing evidence for PE diagnosis, and focus on the challenge of diagnosing PE in special patient populations, such as pregnant women, or patients with a prior VTE. We also discuss novel imaging tests for PE diagnosis and highlight some of the additional challenges that might require adjustments to current diagnostic strategies, such as the reduced clinical suspicion threshold, resulting in a lower proportion of PE among suspected patients as well as the overdiagnosis of subsegmental PE.