Prevention and management of venous thromboembolism in pregnancy: cutting through the practice variation

Soluble Fibrin Monomer Complex and D-Dimer Concentrations Between Patients at Low and High Risk of Venous Thromboembolism Before Delivery According to RCOG Score Assessment: An Observational Study Among 100 Third-Trimester Vietnamese Pregnancies

Background/Objectives: Venous thromboembolism (VTE) is related to maternal mortality, especially after the coronavirus disease (COVID-19) pandemic. The Royal College of Obstetricians and Gynecologists (RCOG) guidelines' risk assessment score has been established to reduce thrombotic complications during pregnancy. Recently, it was found that the soluble fibrin monomer complex (SFMC) could be an alternative to D-dimer (DD), which has been used to assess the risk of VTE. This study aims to reveal the difference between FM and DD concentrations in low- and high-VTE-risk groups according to the RCOG's guidelines. Method: This observational study was conducted at the Department of High-Risk Pregnancy, Tu Du Hospital, Vietnam between August 2023 and April 2024. This study enrolled 100 pregnant women beyond 28 weeks of gestation at low risk (≤2 points) and high risk (≥3 points) of VTE assessment following the RCOG guidelines' score. Blood samples were collected for the SFMC and DD tests before delivery. Statistical tests were used to compare the difference in SFMC and DD concentrations between the two groups. A p-value < 0.05 is considered statistically significant. Results: We found no significant difference in DD and SFMC tests between low and high VTE risk (1.61 [1.30-2.30] vs. 1.51 [0.91-2.13]; 5.00 [1.36-9.78] vs. 3.74 [1.28-14.63], respectively; p > 0.05). The length of hospital stay in the high-risk group is longer than that of the low-risk group and involves postpartum infection. In addition, we found no significant correlation between the gestational age and SFMC or DD concentration. However, a moderate positive correlation between the two tests was found. Similarly, no significant correlation between the VTE score and SFMC or DD concentration was found in the present study. Conclusions: The soluble fibrin monomer complex and D-dimer tests are not significantly different between low-risk and high-risk groups determined through VTE evaluation before delivery according to the RCOG guidelines. The fibrin-linked tests need to be individualized and applied among pregnant women with higher scores of VTE risk based on maternal and pregnancy characteristics during antenatal care. Further studies with a larger number of participants are required to strengthen the findings.

Variation among venous thromboembolism risk assessment tools for postcesarean patients: a retrospective cohort study

Venous thromboembolism (VTE) risk in pregnant women is four to five-fold higher than in nonpregnant women, and the risk of VTE is an additional four-fold higher after Cesarean section compared to normal vaginal delivery. Recommendations regarding anticoagulant prophylaxis are inconsistent across international guidelines, and VTE remains one of the leading causes of maternal morbidity and mortality. This study aimed to compare the need for postcesarean anticoagulation for VTE prophylaxis based on three major guidelines and our own institutional protocol. It was a retrospective cohort study that reviewed the medical records of patients who underwent a cesarean section at a tertiary-level care hospital in the United Arab Emirates (UAE). The need for anticoagulation was assessed using clinical tools from the American College of Obstetricians and Gynecologists (ACOG), Royal College Obstetricians and Gynecologists (RCOG), American College of Chest Physicians (ACCP), and the study site hospital protocol. A total of 1134 postcesarean women, aged 18-55 years, were included in the study. Most patients (87%) were at moderate risk for VTE. According to the study site hospital tool, 90.7% qualified for anticoagulant prophylaxis, while the ACOG, RCOG, and ACCP tools indicated that 0.5, 90.9, and 36.7% qualified, respectively. Enoxaparin was the primary anticoagulant used in 95% of cases. Only one patient developed VTE during the follow-up period. Anticoagulation needs assessment tools vary extensively in their estimations, highlighting the need for a uniform tool across multiple societies to establish a consistent standard of care and guide the development of evidence-based, site-specific protocols.

Differential serum metabolites in patients with pregnancy-associated venous thromboembolism analyzed using GC-MS/LC-MS untargeted metabolomics

Untargeted metabolomics can be used for the comprehensive analysis of metabolite profiles in biological samples without preset targets, making them particularly suitable for exploring metabolic characteristics and potential mechanisms in complex diseases. Therefore, in this study, we employed gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) techniques to analyze the serum metabolic characteristics of patients with pregnancy-associated venous thromboembolism (PA-VTE). In this study, 11 pregnant women with VTE and 11 healthy pregnant women were included in the experimental and control groups, respectively. Using GC-MS, we identified 325 metabolites, with the highest proportion being organic oxygen compounds. Using LC-MS, we identified 3104 metabolites, with the highest proportion being acylcarnitine. The results revealed significant differences in the levels of lipids, organic compounds, and other metabolites between patients compared to healthy pregnant women. Pathways such as pyrimidine metabolism, linoleic acid metabolism, and mineral absorption differed between patients with PA-VTE and controls. Furthermore, we identified biomarkers associated with metabolic processes, such as fatty acids and amino acids (2-hydroxyhexanedioic acid, hexadecenal, palmitoylethanolamide, glycerol-1-phosphate, and N-acetyl-beta-D-glucosamine). These findings revealed the metabolic characteristics of PA-VTE and provided important clues for further research on its pathophysiological mechanisms. Our findings may contribute to the development of new diagnostic markers and support early diagnosis and treatment of PA-VTE.

Asymptomatic Maternal Diseases Presenting with Symptomatic Neonatal Manifestations: A Short Case Series

It is documented that maternal diseases or treatments influence a newborn's clinical status at birth. If a prenatal medical history is not available, or if signs or symptoms of a mother's disease are revealed for the first time during pregnancy or postpartum, their effects on the newborn may be misattributed.

OBJECTIVE

The objective of this study is to emphasize the paramount importance of prenatal care, for both mothers and newborns, as a lack of maternal signs and symptoms during pregnancy does not exclude a potential severe neonatal condition.

MATERIALS AND METHODS

We present a series of three cases of pregnant women who gave birth to very sick preterm newborns that required admission to the Neonatal Intensive Care Unit (NICU). The mothers were asymptomatic during pregnancy and unaware of their subclinical disease. The newborns' complications, considered initially as consequences of prematurity or infection, subsequently revealed transient autoimmune disease in two of the cases (myasthenia gravis and hyperthyroidism) and a severe form of thrombophilia in the third case.

RESULTS

The newborns' diagnosis preceded maternal diagnosis and contributed to the identification of the maternal pathology; adequate treatment was prescribed, with favorable short- and long-term outcomes.

CONCLUSIONS

Prenatal exams and investigations throughout pregnancy are a good opportunity to detect subclinical diseases or predispositions. As newborns usually develop non-specific signs, one should have experience and pay attention to differentiating among etiologies. Our paper takes a reversed approach to the usual medical diagnosis pathway: from infant to mother instead of from mother to infant, proving that inter-specialty collaboration can work bi-directionally.

Pulmonary Embolism Following Preterm Vaginal Delivery: A Case Report

Pulmonary embolism (PE) is a critical medical condition characterized by the obstruction of pulmonary arteries due to blood clots. The incidence of PE is heightened during pregnancy, primarily due to physiological changes such as altered blood flow and a hypercoagulable state. This case report details a pulmonary embolism diagnosed immediately following a preterm delivery, despite the patient receiving prophylactic treatment with low molecular weight heparin (LMWH). The prompt initiation of therapeutic dosing of LMWH was vital in mitigating potentially fatal outcomes. Accurate and timely diagnosis, coupled with appropriate intervention, is essential in preventing severe complications, including maternal mortality. It is imperative to implement effective risk assessment and prophylactic strategies to manage the risk of PE in pregnant women.

Evaluating Thromboprophylaxis Strategies for High-Risk Pregnancy: A Current Perspective

Venous thromboembolism (VTE) represents one of the leading causes of death during pregnancy. The greatest risk for it is the presence of medical or family history of VTE, stillbirth, cesarean section and selected thrombophilia. Appropriate thromboprophylaxis has the potential to decrease the risk of VTE in at-risk pregnant patients by 60-70%. Based on this, the authors reviewed the PubMed, Web of Science and Scopus databases to identify the possibilities of thromboprophylaxis in pregnant patients with a high risk of VTE. Moreover, they summarized its management in specific situations, such as cesarean delivery or neuraxial blockade. Currently, low-molecular-weight heparins (LMWH) are the preferred drugs for anticoagulant thromboprophylaxis in the course of pregnancy and postpartum due to easy administration and a lower rate of adverse events.

Low-molecular-weight heparin and preeclampsia - does the sword cut both ways? Three case reports and review of literature

BACKGROUND

Low-molecular-weight heparins (LMWH) are the most commonly used anticoagulants during pregnancy. It is considered to be the drug of choice due to its safety in not crossing placenta. Considering the beneficial effect in the improvement of microcirculation, prophylactic application of LMWH in patients with preeclampsia became a trend. However, the bleeding risk related with LMWH in preeclampsia patients has seldomly been evaluated. This current study aimed to identify the potential risks regarding LMWH application in patients with preeclampsia.

CASE SUMMARY

Herein we present a case series of three pregnant women diagnosed with preeclampsia on LMWH therapy during pregnancy. All the cases experienced catastrophic hemorrhagic events. After reviewing the twenty-one meta-analyses, the bleeding risk related with LMWH seems ignorable. Only one study analyzed the bleeding risk of LMWH and found a significantly higher risk of developing PPH in women receiving LMWH. Other studies reported minor bleeding risks, none of these were serious enough to stop LMWH treatment. Possibilities of bleeding either from uterus or from intrabdominal organs in preeclampsia patients on LMWH therapy should not be ignored. Intensive management of blood pressure even after delivery and homeostasis suture in surgery are crucial.

CONCLUSION

Consideration should be given to the balance between benefits and risks of LMWH in patients with preeclampsia.

Racial and ethnic disparities in eligibility for postpartum venous thromboembolism prophylaxis in the United States

BACKGROUND

Postpartum venous thromboembolism (VTE) incidence differs by race and ethnicity in the United States. However, it is unclear whether the eligibility criteria for postpartum VTE prophylaxis mirror this disparity.

OBJECTIVE

To characterize the prevalence of risk factors and eligibility for postpartum VTE prophylaxis, among US Birthing people, stratified by race and ethnicity.

METHODS

We analyzed the National Inpatient Sample from October 2015 to December 2019, using diagnosis and procedure codes to identify postpartum individuals and their VTE risk factors. We compared proportion of delivery hospitalizations meeting eligibility for thromboprophylaxis stratified by race or ethnicity, according to American College of Gynecology and Obstetrics, American College of Chest Physicians, Royal College of Obstetricians and Gynecologists (RCOG), and American Society for Hematology guidelines.

RESULTS

Among a national estimate of 14 967 861 delivery hospitalizations in the United States, the proportion of individuals eligible for thromboprophylaxis using the RCOG, American College of Chest Physicians, American College of Gynecology and Obstetrics, and American Society for Hematology guidelines were 32.9%, 8.0%, 0.2%, and 0.2%, respectively. Using the RCOG criteria, non-Hispanic Black individuals had the highest proportion of thromboprophylaxis eligibility (39.7%), whereas it was lowest among Hispanic individuals (30.8%). Racial disparities in thromboprophylaxis eligibility were driven by differences in clinical risk factors (38.8% non-Hispanic Black population vs 30.5% Hispanic population) and cesarean section rates (35.9% vs 32.2%), rather than history of VTE (0.3% vs 0.1%), inherited thrombophilia (0.2% vs 0.2%), or sickle cell disease (0.4% vs <0.1%).

CONCLUSION

Non-Hispanic Black individuals were most likely to qualify for postpartum thromboprophylaxis, attributable to clinical risk factors rather than inherited risk factors. An urgent need exists to better understand ethno-racial disparities in thromboprophylaxis use and to equitably address modifiable risk factors for postpartum VTE.

Acute inferior vena cava thromboembolism in pregnancy

A multigravida in her late 20s was diagnosed with inferior vena cava thrombosis (IVCT) and PE at 26 weeks of pregnancy after a routine prenatal care visit. The patient denied any diseases that could cause IVCT, as well as the presence of any symptoms. Progressive thrombocytopenia was diagnosed in the period until the implantation of the inferior vena cava filter (IVCF). Due to a rupture of foetal membranes and chorioamnionitis, labour was induced at 32 weeks of pregnancy. The IVCF remained in place and anticoagulants were continued through the postpartum period for up to 6 months.

The ART of Thromboprophylaxis in the Prevention of Gestational Venous Thromboembolism

Assisted reproductive techniques (ART) allow infertile couples to conceive. Use of hormones to obtain a controlled ovarian stimulation and an adequate growth of the endometrium preparatory for embryo implantation are not riskless. Among others, thrombotic events can occur during the ovulation induction or pregnancy following ART. As the number of women approaching ART to conceive is steadily increasing, the issue of thrombotic risk in this setting is relevant. Data on the weight of each risk factor and on potential benefit of thromboprophylaxis are largely lacking. In this review, we discuss risk of venous thromboembolism during pregnancy following ART, with a focus on general (i.e.: age, body mass index, thrombophilia, bed rest, transfusions) and ART-specific (i.e., polycystic ovarian syndrome, ovarian hyperstimulation syndrome) risk factors. We also attempt to provide some suggestions to guide clinical practice, based on available data and studies performed outside ART.

Predictors of pregnancy-associated venous thromboembolism: A case-control study

Background

Venous thromboembolism (VTE), manifesting as pulmonary embolism (PE) or deep vein thrombosis (DVT), is the most common cause of morbidity and death during pregnancy and the postpartum period. We conducted this study to describe the predictors of pregnancy-associated VTE (DVT and PE).

Methods

A case-control study was conducted at a tertiary care center in Riyadh. A total of 380 patients were included in this study, 180 of whom were diagnosed with pregnancy-associated thrombosis and 200 of them showed no VTE. Demographic data and data on risk factors of VTE were collected by reviewing the medical charts and the risk assessment tool of the Royal College of Obstetricians and Gynecologists, respectively. The main outcome measures were VTE, manifesting as PE or DVT.

Results

The following factors were identified as the predictors of VTE through multivariate analysis: family history [Odds ratio (OR) = 50.47, 95% Confidence Interval (CI): 6.78–375.64, P < 0.0001)], thrombophilia (OR = 21.99, 95% CI: 2.83–170.63, P = 0.003), and presence of gross varicose veins (OR = 17.15, 95% CI: 3.93–74.87, P < 0.0001).

Conclusions

The findings of this study showed that family history, thrombophilia, and the presence of gross varicose veins were risk factors for VTE, exceeding other transient risk factors. Hence, prophylaxis is highly recommended for those women who present with any of these factors.

Prophylactic Dose of Dalteparin in Pregnant Women With History of Venous Thromboembolisms and/or Thrombophilia: Real-World Data

Women with a history of venous thromboembolisms (VTEs) and/or thrombophilia are at increased risk of VTE during pregnancy. We analysed our cohort of such women who were treated with a prophylactic doses of dalteparin. 152 pregnant women with 179 pregnancies were classified into 3 groups: (1) previous VTE without thrombophilia (122 pregnancies); (2) previous VTE with thrombophilia (26 pregnancies) and (3) thrombophilia only (31 pregnancies). They were treated with prophylactic dalteparin in the prepartum and postpartum periods or only in the postpartum period. Occurrences of symptomatic VTE and bleeding episodes were followed, as well as dalteparin discontinuation and anti-Xa activity. Symptomatic deep vein thrombosis occurred in 4 women (2.2%) with 2 episodes in group 1 (in the postpartum period) and 2 episodes in group 2 (one in the prepartum and another in the postpartum period). Seven episodes (3.9%) of minor bleeding occurred. Dalteparin was not stopped in any women. Anti-Xa levels were within the prophylactic range. Our real-world data show a low incidence of thrombosis and minor bleeding in pregnant women treated with prophylactic dalteparin. The incidence of recurrent VTE was lower than that reported in women with similar risk, but without prophylactic anticoagulation.