The prevention and treatment of venous thromboembolism in pregnancy

Strategies for the prevention of maternal death from venous thromboembolism clinical recommendations based on current literature

Venous thromboembolism (VTE) is one of the leading causes of direct maternal deaths. It has been estimated that approximately 50% of these deaths are potentially preventable. The UK Confidential Enquiries into Maternal Deaths and the National Partnership for Maternal Safety have proposed strategies for the prevention of maternal deaths from VTE based on current guideline recommendations. The main strategies include: - Early recognition and comprehensive assessment of risk factors for VTE at different times from the beginning of pregnancy until patient's discharge from hospital. - Appropriate risk stratification using standardized VTE risk assessment tools (e.g. the Royal College Scoring System). - Risk-based antenatal and postnatal heparin thromboprophylaxis adjusting the heparin dosage and the duration of prophylaxis to the individual patient's risk. - Adequate management of heparin prophylaxis before and after delivery. - Preference of universal rather than selective post-cesarean heparin thromboprophylaxis and application of perioperative mechanical prophylaxis. - Avoidance of gaps in the postpartum prescription of heparin. - Good communication and cooperation between primary and secondary care including community midwifery staff in the postpartum period. - Immediate intravenous administration of (unfractionated) heparin, if pulmonary embolism is suspected. - Critical analysis of all thromboembolic events, particularly in association with maternal death to learn from failures and to realize, if and where improvement is needed. Adequate pharmacological thromboprophylaxis has the potential to reduce the risk of VTE by 60-70% in pregnant women at increased risk.

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.

Role of Ultrasound in the Assessment and Differential Diagnosis of Pelvic Pain in Pregnancy

Pelvic pain (PP) is common in pregnant women and can be caused by several diseases, including obstetrics, gynaecological, gastrointestinal, genitourinary, and vascular disorders. Timely and accurate diagnosis as well as prompt treatment are crucial for the well-being of the mother and foetus. However, these are very challenging. It should be considered that the physiological changes occurring during pregnancy may confuse the diagnosis. In this setting, ultrasound (US) represents the first-line imaging technique since it is readily and widely available and does not use ionizing radiations. In some cases, US may be conclusive for the diagnosis (e.g., if it detects no foetal cardiac activity in suspected spontaneous abortion; if it shows an extrauterine gestational sac in suspected ectopic pregnancy; or if it reveals a dilated, aperistaltic, and blind-ending tubular structure arising from the cecum in suspicious of acute appendicitis). Magnetic resonance imaging (MRI), overcoming some limits of US, represents the second-line imaging technique when an US is negative or inconclusive, to detect the cause of bowel obstruction, or to characterize adnexal masses.

Common iliac vein stenting for May-Thurner syndrome and subsequent pregnancy

BACKGROUND

For women with left common iliac vein compression (ie, May-Thurner syndrome) who undergo venous stenting and subsequently become pregnant, concerns have been raised regarding a possible compromise of stent patency due to compression from the gravid uterus and the hypercoagulability induced by pregnancy. Only a small body of literature exists on this subject, and limited management guidelines are available. The present study was designed to evaluate the safety of iliac vein stenting for May-Thurner syndrome (MTS) with subsequent pregnancy.

METHODS

Female patients who had undergone common iliac vein stenting at our center who were aged 18 to 45 years and had subsequently become pregnant were identified. A retrospective medical record review of eight eligible patients was conducted, recording the demographics, procedural characteristics, and anticoagulation strategies. The primary outcome evaluated was stent patency.

RESULTS

All eight patients had undergone left common iliac vein stenting for MTS. A total of eight stents were placed, and all demonstrated duplex ultrasound patency throughout pregnancy and postpartum. Seven patients delivered healthy pregnancies, and one experienced a stillbirth. The clinical CEAP (clinical, etiologic, anatomic, pathophysiologic) class remained unchanged or improved from pregnancy to postpartum for all patients. The average age at stent placement was 31 ± 5 years, and the average interval from stent placement to pregnancy was 28 ± 19 months. One patient developed nonobstructive deep vein thrombosis (DVT) of the left femoral vein during pregnancy and was treated with therapeutic enoxaparin. The nonobstructive DVT did not compromise the iliac vein stent. Two patients received low-dose aspirin and prophylactic doses of enoxaparin, one for a history of DVT and factor V Leiden and one for a recent history of fertility treatment. The five remaining patients received no anticoagulation, three received low-dose aspirin, and two received no antiplatelet therapy.

CONCLUSIONS

Common iliac vein stent patency was not compromised by subsequent pregnancy in our eight patients with MTS. Furthermore, the stents remained patent throughout pregnancy in patients receiving a wide range of anticoagulation and antiplatelet treatments, suggesting that no uniform therapeutic threshold exists and treatment should be individualized. For most patients, low-dose aspirin alone or no treatment was adequate. This could have implications for counseling women who require intervention for MTS and are of child-bearing age.

How Can Rotational Thromboelastometry as a Point-of-Care Method Be Useful for the Management of Secondary Thromboprophylaxis in High-Risk Pregnant Patients?

Thromboprophylaxis with low-molecular-weight heparin (LMWH) for patients with a history of venous thromboembolism (VTE) is suggested. Rotational thromboelastometry (ROTEM^®) represents an innovative point-of-care method enabling the complex and quick evaluation of hemostasis. However, there are only episodic cases of its use for hemostasis assessment and guidance of LMWH in pregnancy. Therefore, we provide the results of unique prospective and longitudinal monitoring of hemostasis in high-risk pregnant women, which we used for the individualized optimalization of secondary thromboprophylaxis. According to the shortening of clot formation time (CFT) in EXTEM (p = 0.0007 from the 26th gestational week vs. controls) and INTEM (p = 0.002 from the 35th gestational week), increase in alpha angle (AA) in EXTEM, INTEM, and HEPTEM, and the persistence of increase in maximum clot firmness (MCF) in EXTEM, INTEM, and HEPTEM (p < 0.001 from the 26th and 35th gestational week vs. controls for EXTEM and INTEM, p = 0.0012 from the 26th gestational week in HEPTEM), LMWH dose was modified. Even after the postpartum period, AA in EXTEM was steeper than in controls (p = 0.0007), indicating that hemostasis is not fully normalized after 6–8 weeks following delivery. Therefore, ROTEM may be a useful tool for the individual evaluation of the termination of anticoagulant thromboprophylaxis.

Ovarian Vein Thrombosis: A Narrative Review

Ovarian vein thrombosis (OVT) is a rare type of venous thromboembolism. The most common risk factors for OVT include pregnancy, oral contraceptives, malignancies, recent surgery, and pelvic infections; however, in 4 to 16% of cases, it can be classified as idiopathic. Most of the available information regards pregnancy-related OVT, which has been reported to complicate 0.01 to 0.18% of pregnancies and to peak around 2 to 6 days after delivery or miscarriage/abortion. The right ovarian vein is more frequently involved (70-80% of cases). Clinical features of OVT include abdominal pain and tenderness, fever, and gastrointestinal symptoms. The most typical finding is the presence of a palpable abdominal mass, although reported in only 46% of cases. OVT can be the cause of puerperal fever in approximately a third of women. Ultrasound Doppler is the first-line imaging, because of its safety, low cost, and wide availability. However, the ovarian veins are difficult to visualize in the presence of bowel meteorism or obesity. Thus, computed tomography or magnetic resonance imaging is often required to confirm the presence and extension of the thrombosis. In oncological patients, OVT is often an incidental finding at abdominal imaging. Mortality related to OVT is nowadays low due to the combination treatment of parenteral broad-spectrum antibiotics (until at least 48 hours after fever resolution) and anticoagulation (low-molecular-weight heparin, vitamin K antagonists, or direct oral anticoagulants). Anticoagulant treatment duration of 3 to 6 months has been recommended for postpartum OVT, while no anticoagulation has been suggested for incidentally detected cancer-associated OVT.

Benign and malignant tumors of the central nervous system and pregnancy

Tumors of the central nervous system (CNS) are rare entities, typically affecting the very young or the very old, but span a spectrum of disease that may present in any age group. Women of reproductive age are more likely to be affected by benign tumors, including pituitary adenomas and meningiomas, and aggressive intracranial malignancies, such as brain metastases and glioblastoma, rarely present in pregnancy. Definitive management of CNS tumors may involve multimodal therapy, including surgery, radiation, and chemotherapy, and each of these treatments carries risk to the mother and developing fetus. CNS tumors often present with challenging and morbid symptoms such as headache and seizure, which need to be managed throughout a pregnancy. Decisions about timing treatment during pregnancy or delaying until after delivery, continuing or electively terminating a pregnancy, and future family planning and fertility are complex and require a multidisciplinary care team to evaluate the implications to both mother and baby. There are no guidelines or consensus recommendations regarding brain tumor management in pregnancy, and thus, individual treatment decisions are made by the care team based on experiential evidence, extrapolation of guidelines for nonpregnant patients, and patient values and preferences.

Low molecular weight heparins use in pregnancy: a practice survey from Greece and a review of the literature

Background

Use of LMWH in pregnancy is not only limited to VTE management, but it extends, to the management of vascular gestational complications and the optimization of IVF pregnancies despite the lack of concrete scientific evidence. In this context, we conducted the present study aiming to gain insights regarding the use of LMWH during pregnancy and puerperium. We recorded indication for use, diagnostic work-up as well as the safety and efficacy of the treatment, trying to elucidate the clinical practice in our country.

Methods

We analyzed data regarding 818 pregnant women received LMWH during 2010-2015.Our cohort had a median age of 33.9 years and a BMI of 23.6.There were 4 groups: those with a history of VTE [Group-A: 76], those with pregnancy complications [Group-B: 445], those undergoing IVF [Group-C: 132] and those carrying prothrombotic tendency (thrombophilia, family history of VTE, other) [Group-D: 165]. Mean duration of LMWH administration was 8.6 ± 1.5 months. Out of the total number, 440 received LMWH in fixed prophylactic dose, 272 in higher prophylactic-weight adjusted dose and 106 in therapeutic dose. Moreover, 152 women received in addition low-dose acetylsalicylic acid (ASA). 93.8% of pregnancies were single and 6.2% were multiple ones. Live births occurred in 98.7% of pregnancies.

Results

Anticoagulation was efficacious and well tolerated. Seventeen VTE events were recorded; 7 of them antepartum and 10 postpartum. No major bleeding events were observed while 13 clinical relevant non-major bleeding events were recorded. Regarding gestational vascular complications, 28 IUGR events were recorded, as well as 48 cases of preterm labor of which 12 were concomitant with IUGR (25%). Six early pregnancy losses were recorded; there were 3 fetal deaths and 3 cases of pre-eclampsia/eclampsia.

Conclusions

LMWHs are used extensively during pregnancy and puerperium in Greece for VTE treatment and prophylaxis and for a variety of other indications as well. Although the drug has been shown to be both safe and efficacious, its use for some indications has no proven scientific evidence. In order to clearly define the role of LMWHs in pregnancy, beyond thromboprophylaxis, large prospective studies are required, which could be based on the conclusions of this study.

Establishment of a risk assessment tool for pregnancy-associated venous thromboembolism and its clinical application: protocol for a prospective observational study in Beijing

BACKGROUND

The risk of venous thromboembolism (VTE) during pregnancy and puerperal periods is significantly higher than during the non-pregnant period and is one of the major causes of maternal mortality. Developed countries have promulgated guidelines for risk assessment and prevention of maternal VTE, and standardized management has led to a significant reduction in maternal mortality. However, there is a paucity of relevant research related to pregnancy and puerperal VTE in China.

METHODS/DESIGN

We will perform a prospective cohort study and recruit 13,000 pregnant women from 2018 to 2020 in Beijing, China. VTE risk assessment will be conducted using the Royal College of Obstetricians and Gynaecologists (RCOG) pregnancy and puerperal VTE risk-assessment-scoring tool during early and late pregnancy, as well as during the puerperal period. Venous ultrasonography of lower extremities, routine blood tests, and coagulation parameters will be examined. These VTE risk assessments will be performed again if patients have VTE-related symptoms during their pregnancies, or if any of the following occur: (1) patients are hospitalized over 7 days due to any pregnancy complications; (2) patients are placed under strict bed rest for ≥ 3 days to prevent miscarriage. For patients with a confirmed diagnosis of VTE, treatment and follow-up plans will be decided jointly by the obstetricians, vascular surgeons, and pulmonologists. All patients in the study will be followed up by dedicated healthcare providers for up to 42 days postpartum. Statistical analyses will be performed to test the feasibility of the RCOG scoring tool for the Chinese population. The RCOG scoring tool will then be revised based upon the characteristics of the Chinese population, and the revised assessment scoring tool will then be tested in the cohort to evaluate its efficacy. Finally, a pregnancy and puerperal VTE risk-assessment tool will be proposed based on our study results.

DISCUSSION

This study will establish a preliminary VTE risk-assessment tool that is applicable to pregnant and puerperal women in China and provide guidelines for further thrombophylactic interventions. Furthermore, we wish to draw increased attention to pregnancy-associated VTE to reduce VTE-related mortality.

TRIAL REGISTRATION

Chi CTR1800015848 (04/24/2018).

Pregnancy and Pulmonary Embolism

Venous thromboembolism (VTE), referring to both deep vein thrombosis and pulmonary embolism, is a leading cause of death in the developed world during pregnancy. This increased risk is attributed to the Virchow triad, inherited thrombophilias, along with other standard risk factors, and continues for up to 6 to 12 weeks postpartum. During the peripartum period, women should be risk stratified and preventive measures should be initiated based on their risk. Diagnostic tests and treatment strategies commonly used in VTE differ in pregnancy. An understanding of these differences is imperative to diagnose with confidence and to treat appropriately.

Evaluation of therapeutic efficacy of anticoagulant drugs for patients with venous thromboembolism during pregnancy: A systematic review and meta-analysis

A meta-analysis based on published literature was undertaken to evaluate the efficacy of anticoagulant drugs for the treatment of venous thromboembolism during pregnancy. PubMed, Cochrane and Embase databases were searched from inception to September 2018 for relevant studies using indexed words, including qualified case-control and cohort studies. The meta-analysis used odds ratios (OR) and 95% confidence intervals (95% CI) to analyse the primary results. Nine studies were included in this meta-analysis, with a total of 834 cases and 3424 controls. There were no significant differences in the incidence of prenatal haemorrhage (OR 1.08, 95% CI 0.84-1.40), venous thromboembolism (OR 1.30, 95% CI 0.72-2.33) or caesarean section (OR 1.16, 95% CI 0.69-1.98) between the case group and the control group. The incidence of pulmonary embolism was significantly higher in the case group than in the control group (OR 3.90, 95% CI 1.23-12.34). However, there were a few limitations that may have influenced the results, so more randomized double-blind controlled studies of high quality are warranted to confirm the efficacy of anticoagulant therapy for venous thromboembolism in pregnancy.

Guidelines for Antenatal and Preoperative care in Cesarean Delivery: Enhanced Recovery After Surgery Society Recommendations (Part 1)

This Enhanced Recovery After Surgery (ERAS) Guideline for perioperative care in cesarean delivery will provide best practice, evidenced-based, recommendations for preoperative, intraoperative, and postoperative phases with, primarily, a maternal focus. The focused pathway process for scheduled and unscheduled cesarean delivery for this ERAS Cesarean Delivery Guideline will consider from the time from decision to operate (starting with the 30-60 minutes before skin incision) to hospital discharge. The literature search (1966-2017) used Embase and PubMed to search medical subject headings that included "Cesarean Section," "Cesarean Section," "Cesarean Section Delivery" and all pre- and intraoperative ERAS items. Study selection allowed titles and abstracts to be screened by individual reviewers to identify potentially relevant articles. Metaanalyses, systematic reviews, randomized controlled studies, nonrandomized controlled studies, reviews, and case series were considered for each individual topic. Quality assessment and data analyses that evaluated the quality of evidence and recommendations were evaluated according to the Grading of Recommendations, Assessment, Development and Evaluation system, as used and described in previous ERAS Guidelines. The ERAS Cesarean Delivery Guideline/Pathway has created a maternal focused pathway (for scheduled and unscheduled surgery starting from 30-60 minutes before skin incision to maternal discharge) with ERAS cesarean delivery consensus recommendations preoperative elements (anesthetic medications, fasting, carbohydrate supplementation, prophylactic antibiotics/skin preparation, ), intraoperative elements (anesthetic management, maternal hypothermia prevention, surgical technique, hysterotomy creation and closure, management of peritoneum, subcutaneous space, and skin closure), perioperative fluid management, and postoperative elements (chewing gum, management of nausea and vomiting, analgesia, timing of food intake, glucose management, antithrombotic prophylaxis, timing of ambulation, urinary management, and timing of maternal and neonate discharge). Limited topics for optimized care and for antenatal education and counselling and the immediate neonatal needs at delivery are discussed. Strong recommendations for element use were given for preoperative (antenatal education and counselling, use of antacids and histamine, H2 receptor antagonists, 2-hour fasting and small meal within 6 hours surgery, antimicrobial prophylaxis and skin preparation/chlorhexidine-alcohol), intraoperative (regional anesthesia, prevention of maternal hypothermia [forced warm air, warmed intravenous fluids, room temperature]), perioperative (fluid management for euvolemia and neonatal immediate care needs that include delayed cord clamping), and postoperative (fluid management to prevent nausea and vomiting, antiemetic use, analgesia with nonsteroidal antiinflammatory drugs/paracetamol, regular diet within 2 hours, tight capillary glucose control, pneumatic compression stocking for venous thromboembolism prophylaxis, immediate removal of urinary catheter). Recommendations against the element use were made for preoperative (maternal sedation, bowel preparation), intraoperative (neonatal oral suctioning or increased inspired oxygen), and postoperative (heparin should not be used routinely venous thromboembolism prophylaxis). Because these ERAS cesarean delivery pathway recommendations (elements/processes) are studied, implemented, audited, evaluated, and optimized by the maternity care teams, this will create an opportunity for the focused and optimized areas of care research with further enhanced care and recommendation.

Morphological Survey of Placenta in Trombophilia Related Hypoperfusion of Maternal-Fetal Blood Flow

ABSTRACT: Complex and modern obstetric medical care provides a constant improvement for the pregnancy prognosis. Thus, young women with an undiagnosed pathology become pregnant and, during pregnancy, the previously undiagnosed pathology, without any clinical signs and symptoms, becomes present during pregnancy, having an unfavorable impact on the fetus and the health state of the pregnant woman. The gestational syndromes during pregnancy influence the woman’s health state over a long period of time and the quality of the conception product. The recommendation, performance of laboratory tests and imagistic investigations at the right time during pregnancy, as well as a correct interpretation of their results, may prevent the onset of catastrophic occurrences including fetal death in utero and/ or maternal death. We report the case of a 30-year old primigesta, primipara (IGIP) patient with a singleton, naturally obtained pregnancy, severe preeclampsia, severe IUGR and thrombophilia.

Compliance with the 2009 Royal College of Obstetricians and Gynaecologists guidelines for venous thromboembolic disease prophylaxis in pregnancy and postpartum period in Uruguay

: Venous thromboembolism remains as one of the leading causes of maternal death. Prevention of venous thromboembolism in the obstetric population is challenging as recommendations for prophylaxis have low grade of evidence. Risk factors and prophylaxis guidelines have been highlighted by Royal College of Obstetricians and Gynaecologists. In 2014, we developed a written alert following this guidelines to guide thromboprophylaxis. The aim of this study is to assess recommendations compliance. This study was conducted at University-Hospital in Uruguay from January 2014 to December 2016. A total of 1035 women were enrolled and stratified in high, intermediate or low risk based on Royal College of Obstetricians and Gynaecologists guidelines. Thromboprophylaxis was recommended for women at intermediate and high risk. Women were followed up to assess symptomatic thromboembolism or haemorrhagic complications. A total of 309 were pregnant and 731 puerperal. Median age was 24 (19-29) years old. Of them, 3.0% (n = 31) were at high risk and 35.4% (n = 366) at intermediate risk. All high-risk women received prophylaxis with low-molecular-weight heparin. Of the 366 intermediate-risk women, 52.7% received prophylaxis. Venous thromboembolism was developed in only one woman of the intermediate group, who had received prophylaxis. Bleeding complications were not observed. Awareness of the thrombotic risk, as conferred by an easy and suitable risk assessment, has the potential to improve venous thromboembolism prophylaxis in pregnant and puerperal women. We have a good guidelines compliance with the written alert in the high-risk women group. However, we have to improve low-molecular-weight heparin indication in intermediate-risk group, especially in postcaesarean women.