Thrombophilia in pregnancy: a systematic review

Optical coherence tomography angiography evaluation of retinal and choroidal microvascular changes in pregnant women with a history of unexplained recurrent spontaneous abortions

PURPOSE

To study retinal and choroidal microcirculation by optical coherence tomography angiography (OCTA) in pregnant women with unexplained recurrent spontaneous abortion (RSA) and to compare them with healthy pregnant and nonpregnant subjects.

METHODS

Pregnant women with an unexplained history of RSA (group 1), healthy pregnant (group 2), and healthy non-pregnant women (group 3) were included in the study. After a thorough ophthalmologic examination:best-corrected visual acuity, intraocular pressure,slit-lamp biomicroscopy, fundus examination,autorefractometer, biometry, and axial length measurement; OCT and OCTA measurements were performed with Swept Source OCT-Angiography (Topcon Co, Japan).

RESULTS

The nonpregnant group had higher values for central foveal superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel density (VD) and lower values for superior, inferior, and mean VD compared with pregnant groups (p < 0.001). Choriocapillaris values (CC) VD were higher in groups 1 and 2 than in group 3 (p < 0.001). The group with unexplained RSA had a relatively smaller FAZ (foveal avascular zone) area than the group of healthy pregnant women (p:0.047). There were no statistically significant differences between groups in the retina, retinal nerve fiber layer, ganglion cell layer, and choroidal thickness (p > 0.05).

CONCLUSION

Although our study did not identify any etiology in pregnant women with RSA, we observed detectable differences in FAZ area and vessel density values using OCTA, when comparing them with healthy pregnant women and healthy nonpregnant controls. We believe that OCTA, as used in many pathologies such as diabetic and hypertensive retinopathy and retinal vascular occlusion, can also be extended to unexplained RSA both to detect etiology and to monitor treatment in studies with a larger number of patients.

A retrospective study of the management and outcomes of pregnancies with inherited antithrombin deficiency

INTRODUCTION

Antithrombin (AT) deficiency is a rare but highly thrombogenic inherited thrombophilia. Its association with adverse pregnancy outcomes (APO) is undefined. There is limited guidance on managing AT deficiency in pregnancy. Some significant issues remain controversial, including risk assessment for prophylactic anticoagulation, anticoagulant therapy, and monitoring. Our goal was to examine if the antepartum management of patients with AT deficiency affected their pregnancy outcomes.

MATERIALS AND METHODS

This retrospective, single-center observational study included pregnant women with inherited AT deficiency in Peking Union Medical College Hospital between 2013 and 2024.

RESULTS

Seventeen pregnancies in 6 women with AT deficiency were identified. A total of 7 pregnancies received adjusted-dose low-molecular-weight heparin (LMWH) and were monitored by anti-Xa level, AT activity, and D-dimer. There were 5 live births (all received LMWH), 7 second-trimester abortions (1 received LMWH), and 5 early pregnancy losses (1 received LMWH). There were 5 abruptio placentae events (3 received LMWH) and 7 thrombotic events (2 received LMWH).

CONCLUSIONS

AT deficiency is at least an important partial factor contributing to APO. It is suggested to make a full assessment of AT patients both for venous thrombus embolism and APO risk. We observed a high prevalence of heparin resistance and a positive correlation between adequate anticoagulation and pregnancy outcome based on tight monitoring with anti-Xa level and timely adjustment of the LMWH dosage.

Antithrombin testing and treatment in pregnancy: Their real-world relationship to clinical outcomes

BACKGROUND

Antithrombin (AT) deficiency is a severe thrombophilia associated with increased rates of maternal morbidity, mortality, and greater healthcare resource utilization during pregnancy and postpartum.

METHODS

Two large U.S. healthcare databases were queried for women aged 15-44 with delivery-related encounters: Cerner Real-World Data (CRWD, 01/01/2000-12/31/2021) and Premier Healthcare Database (PHD, 01/01/2016-01/01/2019). Individuals receiving cardiopulmonary bypass were excluded. Three cohorts were created: 1) Individuals who had AT levels tested any time between 9-months pre- through 3-months post-delivery (CRWD Test Cohort); 2) individuals prescribed AT concentrate (ATc) within 1-year pre- or 1-year post-delivery in CRWD (CRWD Medication Cohort); and 3) the same criteria as 2) applied to PHD (PHD Medication Cohort).

RESULTS

There were 5411 individuals in the CRWD Test Cohort, 13 in the CRWD Medication Cohort and 38 in the PHD Medication Cohort. Demographic and baseline clinical characteristics were similar across cohorts. AT level testing occurred pre-delivery in 47.9 % of the CRWD Test Cohort and 23.1 % of the CRWD Medication Cohort. ATc was administered during the delivery hospitalization to 0.1 %, 23.1 % and 50.0 % of the CRWD Test, CRWD Medication, and PHD Medication Cohorts, respectively. Across cohorts, 5.4-7.9 % of individuals experienced thrombosis during the delivery-related encounter. Mean (SD) total costs for delivery through 1-year post-delivery were $190,894 ($276,893) with $123,763 ($177,122) of total costs related to abnormal coagulation.

CONCLUSION

Opportunities exist to enhance the care of pregnant individuals with low AT levels throughout pregnancy, aiming for optimal maternal outcomes.

VTE Risk Assessment and Prevention in Pregnancy

Venous thromboembolism (VTE) remains the leading cause of maternal mortality in pregnancy and the postpartum period. In addition to the higher pregnancy-associated baseline VTE risk, there are several well-established risk factors that can further increase the risk of VTE. At present, a thorough interrogation of these risk factors remains our only tool for estimating which pregnant people may be at an increased risk of VTE, and thus potentially benefit from thromboprophylaxis. However, an important knowledge gap still exists surrounding the duration of increased risk and the interaction of risk factors with each other. Furthermore, up to now, once significant risk has been established, prevention strategies have been largely based on expert opinion rather than high-quality data. Recent trials have successfully bridged a proportion of this knowledge gap; however, the challenge of conducting high-quality clinical trials with pregnant people remains. In this article, we provide an update on the recent evidence surrounding VTE risk factors in pregnancy while concurrently outlining knowledge gaps and current approaches to VTE prevention.

Exposure to Macrolides During Pregnancy and the Risk for Spontaneous Abortions: A Population-Based Retrospective Cohort Study

Previous studies evaluating the risk of spontaneous abortions following exposure to macrolides reported controversial results. The goal of the current study was to examine the risk for spontaneous abortions following exposure to macrolides during pregnancy. We conducted a population-based retrospective cohort study by linking three computerized databases: Clalit Health Services drug dispensation database, Soroka Medical Center (SMC) birth database, and SMC hospitalizations database. Multivariate time-varying Cox regressions were performed and adjusted for suspected confounders and known risk factors for spontaneous abortions. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated. A secondary analysis was performed to assess the association between exposure to macrolides in terms of the defined daily dose dispensed and spontaneous abortions. The study cohort included 65,457 pregnancies that ended at Soroka Medical Center between 2004 and 2009, of which 6508 (9.9%) resulted in a spontaneous abortion. A total of 825 (1.26%) pregnancies were exposed to macrolides during the exposure period. Exposure to macrolides was not associated with spontaneous abortions as a group (adjusted HR 1.00 95% CI 0.77-1.31) or as specific medications. There was no evidence of a dose-response relationship between exposure to macrolides and spontaneous abortions. In conclusion, this population-based retrospective cohort study did not detect an increased risk for spontaneous abortion following exposure to macrolides during the first trimester of pregnancy.

VTE risk assessment, prevention and diagnosis in pregnancy

Venous thromboembolism (VTE) is still reported as the leading cause of direct maternal death in pregnancy in serial international reports in developed countries. VTE risk is higher during pregnancy but is further increased by additional well-characterized risk factors. International guidelines recommend that formal VTE risk assessment should be conducted at least in early pregnancy, at delivery and when risk factors change. High quality data supporting optimal VTE prevention strategies are lacking, outside the setting of prevention of VTE recurrence. Moreover, recent high-quality studies have provided much-needed data on diagnostic strategies for pulmonary embolism (PE) in pregnancy. In this review, we summarize knowledge gaps and recently published data in the prevention and diagnosis of VTE in pregnancy. Moreover, we describe ongoing high-quality randomised trials and prospective clinical management studies in this area. High quality clinical studies and trials in pregnancy can be done and must be prioritised, through international network efforts and national funding advocacy. Ultimately, translation of study results to impact upon guidelines and policy will deliver better care to and will protect the lives and health of pregnant people and those contemplating pregnancy throughout the world.

Thrombosis-related characteristics of pregnant women with antithrombin deficiency, protein C deficiency and protein S deficiency in Japan

BACKGROUND

 We previously conducted a primary survey of pregnant women with hereditary thrombophilia based on national surveillance in Japan, but did not examine their thrombosis-related characteristics. Antithrombin (AT) deficiency, protein C (PC) deficiency and protein S (PS) deficiency are the major types of hereditary thrombophilia in Japan.

METHODS

We examined their detailed information related to thrombosis, and evaluated peripartum outcomes in comparison with control data obtained from the Japan Society of Obstetrics and Gynecology.

RESULTS

Definite or probable AT deficiency, PC deficiency and PS deficiency were observed in 80, 50, and 317 pregnancies, respectively, from 2014 to 2018 in Japan, with prevalence rates among total deliveries of 0.011%, 0.007%, 0.044%. The number of pregnancies with AT, PC and PS deficiency might have been as many as 27, 17 and 108 every year if complete answers had been provided. In the peripartum period of current pregnancies, 27.5% of women with AT deficiency, 28.0% with PC deficiency and 13.2% with PS deficiency developed thrombosis (p < 0.001 vs. control). Pregnant women with AT and PC deficiency were more susceptible to thrombosis than those with PS deficiency (P < 0.01). Of the thromboses, 92.3% occurred during pregnancy, 62.8% at less than 15 gestational weeks. The earliest onset of thrombosis was 5 gestational weeks. Prophylactic anticoagulation significantly prevented the onset of both antepartum and postpartum thrombosis (p < 0.0001). The rate of recurrent pregnancy loss in women with low PC or PS activities was significantly higher than in controls (p < 0.0001); however, it is unknown whether recurrent pregnancy loss is related to hereditary PS deficiency. There seem to have been few serious maternal or fetal/neonatal complications due to placental insufficiency related to a hypercoagulable state other than growth restriction.

CONCLUSIONS

This survey revealed the thrombosis-related characteristics of pregnant women with hereditary thrombophilia in Japan. We suggest prophylactic anticoagulation to prevent maternal or fetal/neonatal complications.

The dos, don'ts, and nuances of thrombophilia testing

Considerable progress has been made in elucidating genetic and biologic risk factors for venous thromboembolism (VTE). Despite being able to identify heritable defects in a substantial proportion of patients with VTE, testing has not, in general, proven useful in management. Despite efforts to reduce inappropriate testing, it often falls to the hematologist to consult on patients having undergone thrombophilia testing. Through a series of cases, we discuss how D-dimer testing can be helpful in VTE recurrence risk stratification in younger women as well as how to approach patients with persistently elevated D-dimer levels in the absence of thrombosis. While elevated factor VIII coagulant activity levels are a significant risk factor for a first episode of VTE, its biologic basis is not fully understood, and studies have not shown it to be a useful predictor of recurrence. Abnormal results of genetic tests for methylene tetrahydrofolate reductase or plasminogen activator 1 promoter polymorphisms may be encountered, which carry little if any thrombotic risk and should never be ordered. We also discuss protein S deficiency, the most difficult of the hereditary thrombophilias to diagnose due to a wider "normal" range in the general population as compared with protein C, the presence of both free and bound forms in plasma, and the characteristics of the various assays in use. We also present a rare type of protein C deficiency that can be missed by functional assays using an amidolytic rather than a clotting end point.

To Test or Not to Test: Routine Thrombophilia Diagnostic Screening of Women with Reproductive Failures

BACKGROUND

Recurrent reproductive failure is a global health issue affecting a significant number of women. Thrombophilias have been implicated as a possible cause. Inherited thrombophilias include a single nucleotide variant on factor V Leiden and prothrombin.

OBJECTIVE

The aim of this study was to evaluate the association between the following single nucleotide variants: factor V Leiden (c.1601G>A), the prothrombin gene (c.*97G>A) and the reproductive failure in the Polish population.

METHODS

The study was conducted in a group of 545 patients with recurrent pregnancy loss, RPL (≥2 miscarriages), and in a group of 641 patients with infertility. The distribution of genotypes for the selected variants were determined by RFLP-PCR and by the real-time PCR method.

RESULTS

A variant of the F5 gene was found in 5.14% of patients with RPL and in 6.08% of infertile women. A variant of the F2 gene was identified in 0.73% of patients with RPL and in 2.03% of women with infertility. The frequency in the study groups did not differ from that in the general population. No association between the studied variants of the F5 gene or the F2 gene and the predisposition to reproductive wastage was found.

CONCLUSIONS

Recommendations for routine thrombophilia testing in women with recurrent miscarriages should be revisited. The decision regarding testing should be made individually depending on additional factors indicating an increased risk of venous thromboembolism.

Impact of a previous late miscarriage on subsequent pregnancy outcomes: A retrospective cohort study over 10 years

OBJECTIVE

To explore the prognostic impact of a previous late miscarriage (LM) on the subsequent pregnancy outcomes of women with infertility.

METHOD

This retrospective cohort study included couples who had experienced LM following their first embryo transfer during an in vitro fertilization (IVF) cycle from January 2008 to December 2020. Subgroup analysis and binary logistic regression were performed to evaluate the associations between LM due to different causes and subsequent pregnancy outcomes.

RESULTS

A total of 1072 women who had experienced LM were included in this study, comprising 458, 146, 412, and 56 women with LM due to unexplained factors (unLM), fetal factors (feLM), cervical factors (ceLM; i.e. cervical incompetence), and trauma factors (trLM), respectively. Compared with the general IVF (gIVF) population, the early miscarriage rate was significantly higher in the unLM group (8.28% vs. 13.47%, adjusted odds ratio [OR] 1.60, 95% confidence interval [95% CI] 1.12-2.28; P = 0.01). Furthermore, women in the unLM and ceLM groups had a dramatically increased risk of recurrent LM (unLM: 4.24% vs. 9.43%, aOR 1.91, 95% CI 1.24-2.94; P = 0.003; ceLM: 4.24% vs.15.53%, aOR 2.68, 95% CI 1.82-3.95; P < 0.001) and consequently a reduced frequency of live birth (unLM: 49.96% vs. 43.01%, aOR 0.75, 95% CI 0.61-0.91; P = 0.004; ceLM: 49.96% vs. 38.59%, aOR 0.61, 95% CI 0.49-0.77; P < 0.001) compared with the gIVF population.

CONCLUSION

A previous LM due to an unexplained factor or cervical incompetence was significantly associated with a higher risk of miscarriage and a lower live birth rate after subsequent embryo transfer.

Preeclampsia and the Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is characterized by venous or arterial thrombosis and/or adverse pregnancy outcome in the presence of persistent laboratory evidence of antiphospholipid antibodies (aPLs). Preeclampsia complicates about 10-17% of pregnancies with APS. However, only early onset preeclampsia (<34 weeks of gestation) belongs to the clinical criteria of APS. The similarities in the pathophysiology of early onset preeclampsia and APS emphasize an association of these two syndromes. Overall, both are the result of a defective trophoblast invasion and decidual transformation at early gestation. Women with APS are at increased risk for prematurity; the reasons are mostly iatrogenic due to placental dysfunction, such as preeclampsia or FGR. Interestingly, women with APS have also an increased risk for preterm delivery, even in the absence of FGR and preeclampsia, and therefore it is not indicated but spontaneous. The basic treatment of APS in pregnancy is low-dose aspirin and low-molecular-weight heparin. Nevertheless, up to 20-30% of women develop complications at early and late gestation, despite basic treatment. Several additional treatment options have been proposed, with hydroxychloroquine (HCQ) being one of the most efficient. Additionally, nutritional interventions, such as intake of vitamin D, have shown promising beneficial effects. Curcumin, due to its antioxidant and anti-inflammatory properties, might be considered as an additional intervention as well.

American Society of Hematology, ABHH, ACHO, Grupo CAHT, Grupo CLAHT, SAH, SBHH, SHU, SOCHIHEM, SOMETH, Sociedad Panamena de Hematología, Sociedad Peruana de Hematología, and SVH 2023 guidelines for diagnosis of venous thromboembolism and for its management in special populations in Latin America

Implementation of international guidelines in Latin American settings requires additional considerations (ie, values and preferences, resources, accessibility, feasibility, and impact on health equity). The purpose of this guideline is to provide evidence-based recommendations about the diagnosis of venous thromboembolism (VTE) and its management in children and during pregnancy. We used the GRADE ADOLOPMENT method to adapt recommendations from 3 American Society of Hematology (ASH) VTE guidelines (diagnosis of VTE, VTE in pregnancy, and VTE in the pediatric population). ASH and 12 local hematology societies formed a guideline panel comprising medical professionals from 10 countries in Latin America. Panelists prioritized 10 questions about the diagnosis of VTE and 18 questions about its management in special populations that were relevant for the Latin American context. A knowledge synthesis team updated evidence reviews of health effects conducted for the original ASH guidelines and summarized information about factors specific to the Latin American context. In comparison with the original guideline, there were significant changes in 2 of 10 diagnostic recommendations (changes in the diagnostic algorithms) and in 9 of 18 management recommendations (4 changed direction and 5 changed strength). This guideline ADOLOPMENT project highlighted the importance of contextualizing recommendations in other settings based on differences in values, resources, feasibility, and health equity impact.

Heparin for women with recurrent miscarriage and inherited thrombophilia (ALIFE2): an international open-label, randomised controlled trial

BACKGROUND

Anticoagulant therapy might reduce the number of miscarriages and adverse pregnancy outcomes in women with recurrent pregnancy loss and inherited thrombophilia. We aimed to assess use of low-molecular-weight heparin (LMWH) versus standard care in this population.

METHODS

The ALIFE2 trial was an international open-label, randomised controlled trial undertaken in hospitals in the UK (n=26), the Netherlands (n=10), the USA (n=2), Belgium (n=1), and Slovenia (n=1). Women aged 18-42 years who had two or more pregnancy losses and confirmed inherited thrombophilia, and who were trying to conceive or were already pregnant (≤7 weeks' gestation), were eligible for inclusion. Women were randomly assigned (1:1) to use low-dose LMWH or not (alongside standard care in both groups) once they had a positive urine pregnancy test. LMWH was started at or before 7 weeks' gestation and continued until the end of pregnancy. The primary outcome measure was livebirth rate, assessed in all women with available data. Safety outcomes included bleeding episodes, thrombocytopenia, and skin reactions, and were assessed in all randomly assigned women who reported a safety event. The trial was registered within the Dutch Trial Register (NTR3361) and EudraCT (UK: 2015-002357-35).

FINDINGS

Between Aug 1, 2012, and Jan 30, 2021, 10 625 women were assessed for eligibility, 428 were registered, and 326 conceived and were randomly assigned (164 to LMWH and 162 to standard care). 116 (72%) of 162 women with primary outcome data in the LMWH group and 112 (71%) of 158 in the standard care group had livebirths (adjusted odds ratio 1·08, 95% CI 0·65 to 1·78; absolute risk difference, 0·7%, 95% CI -9·2% to 10·6%). 39 (24%) of 164 women in the LMWH group and 37 (23%) of 162 women in the standard care group reported adverse events.

INTERPRETATION

LMWH did not result in higher livebirth rates in women who had two or more pregnancy losses and confirmed inherited thrombophilia. We do not advise use of LMWH in women with recurrent pregnancy loss and inherited thrombophilia, and we advise against screening for inherited thrombophilia in women with recurrent pregnancy loss.

FUNDING

National Institute for Health and Care Research and the Netherlands Organization for Health Research and Development.

Pathophysiological, immunogenetic, anatomopathological profile of thrombophilia in pregnancy

Thrombophilic states have been associated with early and/or late pregnancy loss and possibly other severe obstetrical complications. Pregnancy-induced hypercoagulability, increased stasis, and the consequences of inherited and acquired thrombophilia are just a few of the factors that contribute to the development of thrombosis in pregnancy. In this review, we illustrate the impact that these factors have on the development of thrombophilia during pregnancy. We also explore how thrombophilia impact pregnancy outcomes. Next, we discuss how human leukocyte antigen G plays a part in thrombophilia during pregnancy by regulating cytokine release to prevent trophoblastic cell invasion and maintain local immunotolerance constant. Human leukocyte antigen class E is briefly explored with thrombophilia in pregnancy. Regarding the anatomopathologic aspect, we describe the different histopathological lesions of the placenta found in women with thrombophilia.

Venous thromboembolism during pregnancy: Trends, incidence, and risk patterns in a large cohort population

OBJECTIVE

To determine the incidence and risk factors for pregnancy-associated venous thromboembolism (VTE).

METHODS

An observational retrospective study was conducted using data from 452 176 live births between the years 2010 and 2019. The study group consisted of women who were diagnosed with VTE during pregnancy or the postpartum period. The exclusion criteria included women who purchased anticoagulant drugs during pregnancy or postpartum. The hazard ratios (HRs) of VTE per week of each trimester and the postpartum period were calculated.

RESULTS

A total of 421 125 live births were included in the study. Among the study population, 302 cases (0.71 cases/1000 pregnancies) were diagnosed with VTE during pregnancy and postpartum. The overall rates of diagnosis did not change significantly during the study period but followed a declining trend in the postpartum period. The highest risk of VTE was found to be during the third trimester (HR 0.002% per week, 95% confidence interval [CI] 0.0016-0.0023), while the lowest rate was during the postpartum period (HR 0.0007% per week, 95% CI 0.0004-0.0011).

CONCLUSION

Pregnancy and the puerperium are well-established risk factors for VTE. The present study demonstrates a declining trend in the risk and incidence of VTE during the postpartum period, which can be explained by a liberal and effective VTE prevention policy.

Prevalence of Inherited Thrombophilia in Women with Recurrent Pregnancy Loss During the First Trimester of Pregnancy

Purpose

This study aims to investigate the prevalence of inherited thrombophilia in women with recurrent pregnancy loss during the first trimester of pregnancy. The study was assessed the potential role of inherited thrombophilia in recurrent miscarriages and evaluate the consequences of this condition on the reproductive outcomes of affected women.

Material and Methods

This study was an analytical descriptive carried out in Khartoum, Sudan. The research comprised 98 controls who had given birth twice or more without experiencing a miscarriage and 120 patients. Each patient had done more than two miscarriages especially when the pregnancy is at its beginning trimester. (APCR), and (PS) were investigated using the clotting approach. There was an assessment of biological activities of (ATIII), (PC), and (PS) for both groups using the chromogenic method.

Results

The average age of the patients was 34, which was higher than the average age of the controls (33.5). The patient group had a much higher rate of multiple miscarriages among the women.: 35 (29.17%), 45 (37.50%), and 40 (33.33%). The incidence of PC deficiencies was determined to be 1.02% (1/98), whereas neither ATIII nor PS deficiencies were seen in the control group (0/98). APCR was more prevalent in the control group (4.10% or 4/98).

Conclusion

Despite contradicting evidence to the contrary in the literature, our findings imply that most miscarriages occur when pregnancy is at the first trimester when a woman is pregnant and they are all caused by thrombophilia.

The role of thrombophilias in reproduction: A swot analysis

Thrombophilia is a group of inherited or acquired coagulation disorders that have been associated with reproductive failure. However, there are still no clear recommendations on whether its inclusion in the initial study of the infertile couple or patients with recurrent implantation failure is necessary. In this discussion paper, based on a SWOT (strengths, weaknesses, opportunities, threats) analysis, the different aspects of the repercussions of thrombophilia screening and treatment in reproduction are evaluated. To avoid possible subjectivity in the analysis and results of this study, researchers followed Oxford criteria for the evaluation of evidence. The results from the evaluation of the reviewed bibliography seem to indicate that, pending new evidence, it would be advisable not to include thrombophilia screening in the initial baseline study of the infertile couple. There is no evidence to support a clear association between thrombophilia and implantation failure or infertility. Thrombophilia testing in this setting may increase cost, with minimal potential benefit and lead to inappropriate use of anticoagulants with possible deleterious adverse effects. Future well-designed studies are needed to assess the possible benefit of anticoagulant therapy in infertile thrombophilic patients with implantation failure.

Clinical risk factors for vasculo-placental disorders: results from a prospective case-control study nested in HEMOTHEPP French cohort study

OBJECTIVE

Determine clinical risk factors for vasculo-placental disorders in singleton pregnancies.

DESIGN

Prospective case-control study nested in HEMOTHEPP French cohort.

SETTING

Women delivered between June, 2015 and January, 2019 in any maternity ward of Finistère.

POPULATION

Cases were women with vasculo-placental disorders (pre-eclampsia, intrauterine growth restriction (IUGR), placental abruption or stillbirth). Controls were women matched for age at delivery and parity.

METHODS

Clinical data were collected by obstetricians or midwives during antenatal care visits and delivery, and recorded by trained research assistants.

MAIN OUTCOME MEASURES

Occurrence of a vasculo-placental disorder.

RESULTS

505 women with vasculo-placental disorder (299 pre-eclampsia, 253 IUGR, 44 placental abruptions, 11 stillbirths) and 1515 matched controls were selected out of 20,075 participants. In multivariable analysis, four clinical parameters were associated with pre-eclampsia: obesity (Odd ratio (OR) = 3.11, 95%CI 2.11-4.58), French overseas origin (OR = 4.41, 95%CI 1.87-10.42), previous vasculo-placental disorder (OR = 5.14, 95%CI 2.72-9.70), aspirin during pregnancy (OR = 10.10, 95%CI 1.99-51.08). Three clinical parameters were associated with IUGR: auto-immune/inflammatory disorder (OR = 3.75, 95%CI 1.83-7.68), previous vasculo-placental disorder (OR = 3.63, 95%CI 2.06-6.41), smoking during pregnancy (OR = 2.66, 95%CI 1.91- 3.71). A previous venous thromboembolism (VTE) was associated with IUGR in univariable but not in multivariable analysis (OR = 3.72, 95%CI 0.82-17.00, p = 0.09).

CONCLUSIONS

Clinical risk factors differ between IUGR and pre-eclampsia, the later, but not the former, being associated with cardiovascular risk factors.

A Retrospective Assessment of Thrombophilia in Pregnant Women with First and Second Trimester Pregnancy Loss

Recurrent Pregnancy Loss (RPL) affects between 1% to 5% of women of reproductive age. It is widely believed that RPL is a complex disorder that is influenced by chromosomal abnormalities, genetic mutations, uterine anatomic deformity, endocrine dysfunction, immunologic factors, infections, and the environment. Thrombotic disorders are a frequent cause of RPL, accounting for almost half of all cases; however, in the rest of the cases, the cause of RPL remains unclear. Therefore, in this study, it was planned to determine the genetic mutations involved in RPL during the first and second trimester of pregnancy. An observational retrospective cohort study was conducted in 2021, collecting data from 157 first trimester miscarriages and 54 s trimester pregnancies. All patients with a panel of laboratory and genetic analysis for thrombophilia were included for data analysis. It was observed that four factors were significantly more prevalent in one of the groups. Factor V Leiden (FVL) homozygosity and antiphospholipid syndrome (APS) antibodies were statistically significantly more common in pregnant women who suffered first trimester pregnancy losses. On the other hand, Protein C deficiency and Glycoprotein Ia polymorphism were statistically significantly more frequent in the second trimester group. The strongest independent risk factors for first trimester pregnancy loss were FVL and prothrombin (PT) compound mutations (OR = 3.11), followed by FVL homozygous mutation (OR = 3.66), and APS antibodies (OR = 4.47). Regarding second trimester pregnancy loss risk factors, the strongest were FVL and PT compound (OR = 3.24), followed by Glycoprotein Ia polymorphism (OR = 3.61), and respectively, APS antibodies (OR = 3.85). Numerous thrombophilic risk factors for early and late pregnancy loss have been found, including several mutations that seem to occur more often either during the first or the second trimester. Even though we are aware of risk-free and efficient diagnostics for thrombophilia abnormalities, no intervention has been proved to be clearly successful after the detection of these variables.

Maternal Inherited Thrombophilia in Monochorionic Twin Pregnancy with Twin-Twin Transfusion Syndrome

BACKGROUND

To study the frequency of inherited thrombophilia in monochorionic twin pregnancies with twin-twin transfusion syndrome (TTTS).

METHODS

At the Department of Obstetrics of the Polytechnic University of Marche (Ancona, Italy) a population of monochorionic diamniotic pregnant women was selected retrospectively. After termination of the pregnancy, genotyping for Factor I, Factor V Leiden, Factor II and Methylenetetrahydrofolate Reductase (MTHFR), as well as activities of the plasma proteins C and S, was performed.

RESULTS

Regarding the 32 patients with TTTS, from a cohort of 104 monochorionic pregnancies recruited, at least one thrombophilic defect was more frequent (OR: 3.24), and the allele polymorphism frequency was higher for Factor I (OR: 4.4) and for Factor V Leiden (OR: 11.66).

CONCLUSIONS

Maternal inherited thrombophilia, possibly also inherited from monochorial fetuses, may result in impaired development of the placental vascular architecture. This inheritance hypothesis may explain why only a fraction of monochorionic diamniotic twins develop TTTS.

Thrombophilia and Pregnancy

Leading cause of death in pregnant women still remains venous thromboembolism, with an incidence of 1.4 to 4.9 per 100,000 pregnancies. A special group of inherited and acquired coagulation disorders associated with a susceptibility to thrombosis is thrombophilia. Physiological changes during the pregnancy also contribute to the occurrence thromboembolic diseases (VTE) in pregnancy. Total rate of venous thromboembolism is 100 per 100,000 pregnancies and 200 per 100,000 births. Etiopathogenesis of obstetric complications in thrombophilia is not clearly defined, which is one of the reasons for the occasional failure of therapy. In pregnancies with hereditary thrombophilia the oxidative stress is considered to be a cause of complications, similar to preeclampsia. Based on the findings so far, additional research should clarify questions regarding the anticoagulants role in pregnancy loss prevention. In this paper, we analyze the effect of the screening on pregnancy outcomes, consider the justification for the use of anticoagulation therapy in difficult situations, discuss about previous knowledge in the field and argue the use of new specific protocols. In short, we address the justification for prescribing anticoagulants and evaluation of their effect within thrombophilia therapeutic strategies.

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.

Pregnancy and thrombosis risk for women without a history of thrombotic events: a retrospective study of the real risks

Background

During pregnancy and puerperium women are at high VTE risk. Current guidelines recommend dynamic VTE-risk assessment during pregnancy. Based on related RCOG-guidelines we constructed a digital VTE-risk assessment tool: PATrisks (www.PATrisks.com). Using this tool, we retrospectively evaluated the thrombotic risk in 742 women from our previous work, women who received thromboprophylaxis based on clinical experience for A) pregnancy complications, B) IVF treatment and C) prothrombotic tendency, in order to investigate whether that practice was justified according to the PATrisks scoring system for VTE prevention.

Methods

Women with pregnancy complications [Group-A: 445], women who had undergone IVF [Group-B:132] and women with a prothrombotic tendency (thrombophilia, family history of VTE, other) [Group-C:165] were assessed using the PATrisks scoring system for thrombotic risk. The women were assigned into one of the following risk categories: low (score ≤ 2), intermediate (score = 3) and high (score ≥ 4). Further analysis per risk factor type (pre-existing or obstetric) and for various combinations of them, was also performed. We evaluated thrombotic risk early in pregnancy, and in the peripartum period.

Results

The mean risk score antepartum was higher for women in Group B (3.3 in comparison with 1.9 and 2.0 in Group A and Group C respectively). Moreover, the risk score increased significantly postpartum for all Groups. The chi-square test also proved that there was a higher percentage of women at high or intermediate risk in group B compared to C before birth (55.3% vs.26.1% respectively, p < 0.0001, OR: 3.5, 95% CI: 2.2 – 5.7) and similarly after birth (85.6% vs. 56.4%, OR: 4.6, 95%CI: 2.6–8.2, p < 0.0001). In total 12 (1.6%) out of 742 women experienced thrombotic events, whether pre- or post-partum.

Conclusions

LMWHs are widely prescribed during pregnancy for a number of indications, even when a proven scientific basis for such a practice is lacking. However, a considerable percentage of women were already at VTE-risk according to PATrisks and might have derived an additional benefit from LMWH in the form of VTE prevention. The rational use of these drugs should be optimized by establishing and implementing routine risk assessment for all pregnant women and by providing the necessary education to healthcare professionals.

Management of Antithrombin Deficiency in Pregnancy

Antithrombin (AT) deficiency is a high-risk thrombophilia and a rare condition. The risk of venous thromboembolism (VTE) is increased in AT-deficient women during pregnancy and the postpartum period and is especially high in women with a prior history of VTE. A thorough assessment of VTE risk is recommended in pregnant AT-deficient women, comprising the degree and type of AT deficiency, genetic mutations, personal and family history, and additional preexisting or pregnancy-specific risk factors. Due to a lack of adequate study data, there is limited guidance on the management of AT deficiency in pregnancy, including the need for prophylactic anticoagulation, the appropriate dose of low-molecular-weight heparin (LMWH), and the role of AT substitution. LMWH is the medication of choice for the pharmacological prophylaxis and treatment of VTE in pregnancy. Patients with a history of VTE should receive full-dose LMWH during pregnancy and the postpartum period. AT concentrates are a treatment option when anticoagulation is withheld in potentially high-risk events such as childbirth, bleeding, or surgery and in cases of acute VTE despite the use of therapeutic dose anticoagulation. Women with AT deficiency should be counseled at specialized centers for coagulation disorders or vascular medicine, and close cooperation between obstetricians and anesthesiologists is warranted before delivery and during the peripartum period.

Hemostasis System and Plasminogen Activity in Retrochorial Hematoma in the First Trimester of Pregnancy

(1) Background: The components of the fibrinolytic system and its main component, plasminogen, play a key role in the first months of pregnancy. The effect of autoantibodies interacting with plasminogen in the formation of retrochorial hematoma is unknown. The aim of our study was to determine the role of plasminogen and IgA, IgM, and IgG, which bind to plasminogen, in retrochorial hematoma. (2) Methods: Prothrombin time (PT), thrombin time (TT), partial activated thromboplastin time (aPTT), soluble fibrin-monomer complex (SFMC), D-dimer, plasminogen activity (%Plg), plasminogen concentration (Plg), and the levels of IgG (IgG-Plg), IgM (IgM-Plg), IgA (IgA-Plg) interacting with plasminogen were determined in plasma samples of 57 women with normal pregnancy and 16 with retrochorial hematoma. (3) Results: %Plg in plasma samples from women with retrochorial hematoma was significantly lower than in plasma samples from women with normal pregnancy. The diagnostic significance of %Plg in the ROC analysis was AUC = 0.85. A direct correlation was found between aPTT and the level of autologous IgM interacting with plasminogen. (4) Conclusions: A decrease in the activity of plasminogen in the blood serum of women in the first trimester of pregnancy may indicate disturbances in the hemostasis system and the formation of retrochorial hematoma. According to the results of the study, it is possible to recommend the determination of plasminogen activity in the management of pregnant women in gynecological practice.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

Evolving Knowledge on Primary and Secondary Prevention of Venous Thromboembolism in Carriers of Hereditary Thrombophilia: A Narrative Review

The association between heritability of venous thromboembolism (VTE) and thrombophilia was first reported clinically in 1956, later followed by the first description of a congenital cause of hypercoagulability-antithrombin deficiency-in 1965. Since then, our knowledge of hereditary causes of hypercoagulability, which may predispose carriers to VTE has improved greatly. Novel genetic defects responsible for severe thrombophilia have been recently identified and we have learned that a wide range of interactions between thrombophilia and other genetic and acquired risk factors are important determinants of the overall individual risk of developing VTE. Furthermore, therapeutic strategies in thrombophilic patients have benefited significantly from the introduction of direct oral anticoagulants. The present review is an overview of the current knowledge on the mechanisms underlying inherited thrombophilia, with a particular focus on the latest achievements in anticoagulation protocols and prevention strategies for thrombosis in carriers of this prothrombotic condition.

Thrombophilia screening in women with recurrent first trimester miscarriage: is it time to stop testing? - a cohort study and systematic review of the literature

OBJECTIVE

There are numerous studies reporting a disproportionally high prevalence of thrombophilia in women with a history of recurrent miscarriage (RM), which has led to overdiagnosis and treatment without an improvement in clinical outcomes. The objective of our study was to assess the prevalence of inherited and acquired thrombophilia in a large cohort of women with a history of early RM using internationally agreed diagnostic criteria and inclusion parameters and compare it to the meta-analysis results of existing literature.

METHODS

DESIGN: Retrospective cohort study and systematic review of literature.

SETTING

This is a retrospective cohort study set-up in two dedicated tertiary centres for women with RM in Southwest London and Surrey. We reviewed all the available literature related to causes of RMs. We ascertained the prevalence of thrombophilia in the study population and compared it with historical and published prevalence in the general population.

PARTICIPANTS

1155 women between 2012 and 2017. All patients had three or more first trimester miscarriages and a full thrombophilia screen.

RESULTS

The overall prevalence of thrombophilia in our study population is 9.2% (106/1155) with 8.1% (94/1155) of cases positive for inherited thrombophilia, which is similar to the general population; Factor V Leiden (4.9%; 57/1155) and prothrombin gene mutation (2.9%; 34/1155) were the most common inherited thrombophilias, while only 1% (12/1155) tested positive for acquired thrombophilia. Persistent positive lupus anticoagulant (LA) was found in 0.5% (6/1155) and persistent positive anticardiolipin (ACL) antibodies with a value ≥40 U/mL was found in 0.5% (6/1155) of patients. Tests for LA/ACL were performed a minimum of 12 weeks apart thus meeting the revised Sapporo criteria for a diagnosis of antiphospholipid syndrome.

CONCLUSION

The findings of our study demonstrate that the prevalence of inherited thrombophilia is similar in women with RM to that in the general population. Similarly, the prevalence of acquired thrombophilia, using the revised Sapporo criteria, in the cohort of RMs is similar to that in the general population. Therefore, we do not recommend investigation or treatment of inherited or acquired thrombophilia in women with RM.

PROSPERO REGISTRATION NUMBER

CRD42020223554.

Association Between ABO Blood Group and Venous Thromboembolism Risk in Patients With Peripherally Inserted Central Catheters: A Meta-analysis and Systematic Review

Background

Previous studies have evaluated the association between ABO blood group and venous thromboembolism (VTE) risk in patients with peripherally inserted central catheters (PICCs). However, it remains unclear whether ABO blood groups are associated with PICC-associated VTE risk. Therefore, we conducted a meta-analysis of related studies to elucidate the potential role of ABO blood group as a risk factor for PICC-associated VTE.

Methods

All detectable case–control and cohort studies comparing the role of ABO blood group as a risk factor for PICC-associated VTE were collected for this analysis by searching PubMed, Embase, CNKI, Web of Science, and Wanfang. We conducted a meta-analysis of the eligible studies and computed the summary risk estimates with random or fixed effects models.

Results

A total of four studies involving 7,804 patients were included. Meta-analysis of the studies showed that the risk of PICC-associated VTE was significantly higher in blood types A [odds ratio (OR)=1.54, 95% CI=1.17–2.03), p=0.002], B (OR=2.35, 95% CI=1.71–3.23, p<0.0001), and AB (OR=2.55, 95% CI=1.68–3.88, p<0.0001) and lower in blood types O (OR=0.58, 95% CI=0.45–0.74, p<0.0001). Subgroup analysis based on ethnicity demonstrated that blood type O may be a genetic protective factor for PICC-associated VTE in Asians. Among Caucasians, individuals with blood types B and AB have a higher risk of PICC-associated VTE. Blood types A, B, and AB are risk factors for PICC-associated VTE in Asians.

Conclusions

Blood type O is associated with a decreased risk of PICC-associated VTE, especially in Asian populations. Moreover, blood types A, B, and AB are risk factors for PICC-associated VTE.

Low molecular weight heparin and pregnancy outcomes in women with inherited thrombophilia: A systematic review and meta-analysis

AIM

To determine whether the use of low molecular weight heparin (LMWH) improves the pregnancy outcomes in women with inherited thrombophilia by conducting a meta-analysis of randomized controlled trials and observational studies.

METHODS

A systematic literature search of several databases was conducted through September 19, 2020 to identify relevant studies. The outcomes of interest included live birth and adverse pregnancy outcomes (APOs). The overall risk estimates were pooled using random-effects meta-analysis.

RESULTS

Ten randomized controlled trials and 12 cohort studies were included. In the meta-analyses of randomized controlled trials, the effectiveness of LMWH-treatment was found to be statistically significant in decreasing the risk of APOs (risk ratio [RR] = 0.76; 95% confidence interval [CI]: 0.61-0.95; p = 0.020), rather than in increasing the rate of live birth (RR = 1.12; 95% CI: 0.93-1.34; p = 0.230). In the meta-analyses of cohort studies, results showed that the use of LMWH was associated with a significantly higher proportion of live birth (RR = 1.86; 95% CI: 1.09-3.19; p = 0.020) as well as a significantly lower ratio of APOs (RR = 0.46; 95% CI: 0.31-0.69; p < 0.001) in women with inherited thrombophilia.

CONCLUSIONS

The use of LMWH may have a potentially beneficial effect on reducing the risk of APOs and even increasing the live birth rate in women with inherited thrombophilia. Further well-designed clinical trials with large samples are needed to address the role of LMWH in improving pregnancy outcomes among pregnant women with inherited thrombophilia.

Peripartum management of hereditary thrombophilia: results of primary surveillance in Japan

This study investigated patients with thrombophilia and current peripartum management practices based on national surveillance in Japan. Between 2014 and 2018, antithrombin (AT), protein C (PC) and protein S (PS) deficiency were observed in 84, 67, and 443 pregnancies, respectively, with incidence rates among total deliveries at 0.012%, 0.009%, and 0.061%. The percentage of institutions that measured both antigens and AT, PC, and PS activity for the diagnosis of thrombophilia was 50.2%, and 46.9% of institutions did not perform gene analysis. Prophylactic anticoagulation therapy was used in the ante- and postpartum management of patients with AT deficiency at 67.1% and 66.3% of institutions, most commonly with 10,000 units of unfractionated heparin. Ante- and postpartum management of PC and PS deficiency was performed at 75.3% and 67.1% of institutions. Approximately half of the institutions performed peripartum prophylactic AT supplementation for AT deficiency. Low trough AT activity before supplementation was most commonly 50 ≤  < 70%, and the highest AT supplementation was 1500 ≤  < 3000 units. The number of pregnancies with AT, PC and PS deficiency might be as many as 29, 23 and 151 every year in Japan if complete answers were provided.

Prevention of venous thromboembolism in pregnant women with congenital antithrombin deficiency: a retrospective study of a candidate protocol

BACKGROUND

The best thromboprophylaxis for pregnant women with congenital antithrombin deficiency (CAD) is controversial.

OBJECTIVE

To clarify the effectiveness of a protocol for venous thromboembolism (VTE) prevention in pregnant women with CAD.

METHODS

Women at high risk of VTE were administered antithrombin concentrate and heparin after conception, whereas those at low risk of VTE were administered heparin alone until delivery. All women received antithrombin concentrate at delivery except for one who was diagnosed with CAD.

RESULTS

Ten women had CAD, including one in the high-risk group and nine in the low-risk group. No women had VTE at delivery as per the protocol for VTE prevention. Almost all women had increased antithrombin activity before delivery followed by maintenance at ≥ 70% due to antithrombin concentrate administration. VTE prophylaxis during and after delivery was successful in all women with CAD. However, one woman in the low-risk group did not receive heparin and developed VTE induced by severe hyperemesis at 9 gestational weeks, before the diagnosis of CAD. Women in the high-risk group received antithrombin concentrate after delivery but had increased D-dimer levels at postpartum.

CONCLUSIONS

Our protocol to prevent VTE in pregnant women with CAD is safe and effective.

Risk of Thrombosis, Pregnancy Morbidity or Death in Antiphospholipid Syndrome

The antiphospholipid syndrome is an autoimmune disease characterized by thrombosis and pregnancy morbidity. The manifestations are caused by antibodies targeting cell membrane phospholipids and/or associated proteins. The triggers leading to these antibodies' production are unknown but recent work suggests cross-reactivity between the autoantigens and peptides produced by the intestinal microbiome. Work on how the autoantibodies could cause clinical manifestations implicates different mechanisms. Binding to surface proteins of different cell types can induce intracellular signaling leading to cell activation and tissue factor expression. Complement activation and neutrophil extracellular-traps are also involved, and recent evidence implicates endothelial protein C receptor-lysobisphosphatidic acid complex. Pregnancy is a high-risk situation for antiphospholipid syndrome patients due to the increased risk of thrombosis and obstetric complications. Epidemiological and clinical research on APS is hampered by heterogeneity in populations, testing and treatment strategies. About one in 10 to one in fifty APS pregnancies is complicated by thrombosis, despite treatment. Pregnant patients with prior thrombosis are prescribed therapeutic dose heparins and low dose aspirin. Without prior thrombosis a prophylactic dose is used. The most frequent obstetrical manifestation is recurrent early pregnancy loss. The association of APS antibodies with late pregnancy loss is stronger, however. Prevention of recurrence is achieved with aspirin and prophylactic dose heparin, although the evidence is of low certainty. The third obstetrical classifying manifestation comprises preterm delivery due to placenta-mediated complications and is treated in subsequent pregnancies with aspirin with or without prophylactic dose heparin, again based on low quality evidence. New therapies are under investigation.

Venous thromboembolism during pregnancy and postpartum period

Venous thromboembolism (VTE) is one of the leading causes of maternal mortality. Rates of VTE during pregnancy and the postpartum period have not decreased over the past two decades and pregnancyassociated VTE continues to pose a significant health challenge. Pregnant and postpartum women are at a higher risk for VTE owing to many factors. There are hormonally mediated and pregnancy-specific alterations of coagulation that favor thrombosis, including increased production of clotting factors. There are physiologic and anatomic mechanisms that also contribute, including a decreased rate of venous blood flow from the lower extemities as pregnancy progresses. Cesarean delivery also introduces VTE risk. In addition, studies have demonstrated that pregnancy-associated complications such as pre-eclampsia or peri-partum infections are associated with increased VTE rates. In this review, we discuss the recent epidemiological studies, pathogenesis, risk factors and clinical presentation as well as therapeutic options for VTE during pregnancy and the postpartum period. We also provide proposed diagnostic algorithms for diagnosis and management of VTE during pregnancy and the postpartum period based on updated evidence. Finally, we highlight knowledge gaps to guide future research.

Thrombophilia, Thrombosis and Thromboprophylaxis in Pregnancy: For What and in Whom?

Compared with nonpregnant women, pregnancy carries a four- to fivefold higher risk of venous thromboembolism (VTE). Despite increasing use of heparin prophylaxis in identified high-risk patients, pulmonary embolism still is the leading cause of maternal mortality in the western world. However, evidence on optimal use of thromboprophylaxis is scarce. Thrombophilia, the hereditary or acquired tendency to develop VTE, is also thought to be associated with complications in pregnancy, such as recurrent miscarriage and preeclampsia. In this review, the current evidence on optimal thromboprophylaxis in pregnancy is discussed, focusing primarily on VTE prevention strategies but also discussing the potential to prevent recurrent pregnancy complications with heparin in pregnant women with thrombophilia.

Reproductive Failure and Thrombophilia: Not Enough Evidence for a Tight Bond

OBJECTIVES

The role of hereditary thrombophilia in reproductive failure (RF) is strongly debatable. In this retrospective single-center study, we analyzed pregnancy outcome in 175 women screened for thrombophilia after at least one event of RF.

RESULTS

The prevalence of thrombophilia in our cohort was 33.4%. Pregnancy survival curves were not different according to severity (log-rank, p = 0.302) or type of thrombophilia (log-rank, p = 0.532). In total, 81.7% of 175 subsequent pregnancies were proceeded with LMWH. Concomitant use of ASA was prescribed in 75 pregnancies according to physician choice. The primary endpoint was live birth rate (LBR) that succeeded in 152/175 next pregnancies (86.8%) and late obstetric complications (LOBC) which occurred in 17/175 next pregnancies (9.8%). In logistic regression analysis, neither the severity nor the type of thrombophilia was important for any pregnancy outcome (LBR or LOBC). Considering therapeutic interventions, the use of LMWH ± ASA was not related to LBR or LOBC. The only factor inversely related to LBR was age above the cutoff value of 35.5 years (p = 0.049).

CONCLUSIONS

Incidence of thrombophilia is increased among women with RF, but the severity or type of thrombophilia is not related to pregnancy outcome.

Examination of in Factor V Leiden and Prothrombin II Thrombophilic Mutations in Czech Young Women Using ddPCR-Prevalence and Cost-Benefit Analysis

BACKGROUND

Thrombophilic mutations in genes for factor V Leiden and factor II prothrombin are among the most important risk factors for developing the thromboembolic disease (TED), along with the use of oral contraceptives (OCs) or smoking.

AIM

This study aimed to investigate the occurrence of risk factors in young women using droplet digital PCR (ddPCR) and, based on the results of this investigation, to perform a cost-benefit analysis of ddPCR-based screening in young women starting to take OCs compared to the treatment costs of patients who develop preventable TED in the Czech Republic.

METHODS

In this cross-sectional study, female university students filled in a questionnaire and provided a blood sample for DNA isolation and ddPCR analysis of both aforementioned genetic risk factors. The results, along with data from literature and web search, were used for cost-benefit analysis valid for the Czech Republic.

RESULTS

Out of 148 participants, 30 (20%) were smokers and 49 (33%) took OCs. A mutation was confirmed in 6 women (4.1%) in the factor V gene and in 3 women (2%) in the factor II gene, respectively. A model calculation on a cohort of 50,000 women starting to use contraceptives in the Czech Republic every year showed that at maximum compliance, (i.e., non-use of OC and smoking cessation), screening could prevent 68 cases of TED over the course of the mean period of OC use (5.7 years). Economically, the costs of testing in this cohort (2.25 mil. USD) would be significantly lower than prevented treatment costs (16 mil. USD at maximum compliance); the cost-benefit break-even point would be at 14.1% compliance.

CONCLUSION

The cost-benefit analysis based on our results indicates that screening for factor V Leiden and factor II prothrombin in young women before starting to use OCs would, in the conditions of the Czech Republic, likely be highly economically effective.

Low molecular weight heparin or LMWH plus aspirin in the treatment of unexplained recurrent miscarriage with negative antiphospholipid antibodies: A meta-analysis of randomized controlled trial

OBJECTIVE

Unexplained recurrent miscarriage (uRM) has caused serious distress to women of childbearing age, and effective treatment is particularly important. The aim of this meta-analysis is to compare the efficacy of low molecular weight heparin (LMWH) and LMWH combined with aspirin for uRM.

METHODS

Databases including PubMed, Web of Science, Embase, Scopus and the Cochrane Library databases were electronically searched to identify randomized controlled trials that reported the LMWH or LMWH combined with aspirin for women with uRM and negative antiphospholipid antibodies (aPL). The retrieval time is limited from inception to June 2021. Two reviewers independently screened literature, extracted data, and assessed risk bias of included studies. Meta-analysis was performed by using STATA 12.0 software.

RESULTS

A total of 7 studies involving 1849 patients were included. The meta-analysis results showed that compared with the control group, both LMWH and LMWH + aspirin interventions showed no substantial influence on miscarriage rate (LMWH: RR = 0.69, 95%CI: 0.34-1.39, P = 0.293, LMWH + aspirin: RR = 0.62, 95%CI: 0.30-1.27, P = 0.19) and the occurrence of pre-eclampsia (LMWH: RR = 1.1, 95%CI: 0.53-2.31, P = 0.792; LMWH + aspirin: RR = 1.49, 95%CI: 0.25-8.79, P = 0.662). LMWH therapy had no influence on the live births (RR = 0.99, 95%CI: 0.92-1.06, P = 0.72). Subgroup analysis showed that enoxaparin is not effective in women with uRM and negative aPL (miscarriage rate: RR = 0.82, 95%CI: 0.31-2.19, P = 0.695; pre-eclampsia: RR = 1.03, 95%CI: 0.46-2.33, P = 0.936).

CONCLUSIONS

LMWH and LMWH combined with aspirin therapy cannot improve the pregnancy outcome of women with uRM and negative aPL. However, the above conclusions are still required to be verified through more RCTs due to the limited quantity of included studies.

Obstetric venous thromboembolism prophylaxis, risk factors and outcomes

PURPOSE OF REVIEW

Risk factors for obstetric venous thromboembolism (VTE), a leading cause of maternal mortality in the United States, are increasing on a population basis. This review provides the obstetrician with an update of current issues related to obstetric VTE risk, prophylaxis, outcomes, anaesthesia considerations and future research opportunities.

RECENT FINDINGS

Obstetric VTE affects approximately 1 per 1000 pregnancies and accounts consistently for 9-10% of maternal deaths in the United States. In industrialized countries, risk factors for VTE, including overweight/obesity, caesarean delivery and obstetrical complications such postpartum haemorrhage and infection continue to increase. VTE prophylaxis is central to reducing maternal mortality. However, recommendations for prophylaxis from leadership societies vary widely. In the UK, maternal mortality risk from VTE has decreased significantly in the setting of broader heparin prophylaxis. In the United States where mechanical VTE prophylaxis is used more commonly, mortality risk has remained constant.

SUMMARY

Obstetric VTE is a leading cause of maternal mortality in the United States. The incidence of risk factors for obstetric VTE continues to increase. Currently, recommendations for obstetric VTE prophylaxis vary substantially. Opportunities for research in this area exist to optimize prophylaxis and improve maternal outcomes.

Approach to the Evaluation and Treatment of Venous Thromboembolism in Pregnancy

Thrombosis in pregnancy is a major cause of maternal and fetal morbidity and mortality. Risk stratification of venous thromboembolism (VTE) during pregnancy is complex. The hypercoagulability observed in pregnant women can reduce bleeding during childbirth, but may cause thrombosis especially in the presence of additional prothrombotic risk factors such as antiphospholipid antibodies or genetic thrombophilic defects. The availability of large datasets allows for the identification of additional independent risk factors, including assisted reproductive technologies (ARTs), endometriosis, and recurrent pregnancy loss. Data on the risk of VTE linked to COVID-19 in pregnant women are very limited, but suggest that infected pregnant women have an increased risk of VTE. Current guidelines on the prevention and treatment of VTE in pregnancy are based on available, albeit limited, data and mainly present expert opinion. Low-molecular-weight heparins (LMWHs) are the mainstay of anticoagulation to be employed during pregnancy. Administration of LMWH for VTE treatment in pregnancy should be based on the personalized approach, taking into account a weight-based adjusted scheme. During gestation, due to physiological changes, in women at high risk of VTE, monitoring of anti-Xa activity is performed to ensure adequate LMWH dosing. As for the treatment duration for pregnant women with acute VTE, guidelines suggest that anticoagulation should be continued for at least 6 weeks postpartum for a minimum total duration of therapy of 3 months.

Factor V Leiden G1691A and Prothrombin Gene G20210A Mutations on Pregnancy Outcome

Factor V Leiden (FVL) G1619A mutation and prothrombin gene (PTG) G20210A are the most common inherited thrombophilias. They have been associated with various obstetric complications such as venous thromboembolism, recurrent pregnancy loss, preeclampsia, abruptio placentae, and small for gestational age fetus. The prevalence of these two mutations is 3-15% in Caucasians and is assumed to be far less common in other ethnic populations. However, there have been several controversies regarding advising routine screening of these thrombophilias because of a widely variable strength of association between different ethnic groups, as well as contradictory conclusions by different studies in regards to the association. In this study, the literature was analyzed thoroughly for the effect of FVL G1619A and PTG G20210A mutations on various obstetric outcomes. A review of multiple case-control and prospective studies suggests that despite the availability of robust data on this subject the results remain inconclusive and insubstantial. Further superior quality research, preferably prospective studies, is warranted to conclusively establish this relationship and to enable practitioners to follow a definitive protocol in the screening of various populations for these mutations to achieve an improved pregnancy outcome.

Expert review: prevention of obstetrical venous thromboembolism

Venous thromboembolism represents a persistent proportionate cause of maternal mortality in the United States accounting for 9% to 10% of maternal deaths. Given that overall maternal mortality rose >40% since the late 1990s, it is likely that absolute venous thromboembolism mortality risk increased as well. This persistent risk may be secondary to increases in broad population-based risk factors for venous thromboembolism such as obesity and cesarean delivery. Widespread adoption of perioperative cesarean mechanical thromboprophylaxis is associated with reduced risk for venous thromboembolism events but has not been sufficient to reduce mortality. Experts agree that improved clinical care is required to reduce risk as it is unlikely that trends in venous thromboembolism risk factors will reverse course anytime soon. Experts further agree that improving prophylaxis and prevention may provide the largest benefit. However, how to best improve prophylaxis is highly controversial with both experts and guidelines in disagreement. In the United Kingdom, mortality risk decreased substantially following the 2004 recommendations for broader heparin prophylaxis without evidence of increased mortality risk from hemorrhage. A key clinical question in the United States is whether heparin prophylaxis should be expanded to patients hospitalized for cesarean delivery or an antepartum indication. Some experts, including us, support expanded heparin prophylaxis. Evidence supporting heparin prophylaxis includes (1) demonstration of safety and efficacy in the United Kingdom, (2) that mechanical prophylaxis-the primary alternative to heparin-has major limitations outside the immediate perioperative setting, and (3) that hospitalized cesarean and antepartum patients are at high relative risk of events. Experts against broader heparin prophylaxis cite concerns related to safety, efficacy, and cost. This expert review focused on whether heparin prophylaxis should be routinely used during antepartum hospitalizations and after cesarean delivery. First, we review the differences in major society guidelines. Second, we review arguments for and against broader heparin prophylaxis. Third, we discuss what future research may be most likely to further inform best practices. Fourth, we review practical clinical considerations with heparin prophylaxis, including access to neuraxial anesthesia. Given the best available data, we concluded that expanding heparin prophylaxis represents a modest intervention with the potential to meaningfully reduce venous thromboembolism mortality.

Prothrombotic state associated with preeclampsia

PURPOSE OF REVIEW

Preeclampsia is a common complication of pregnancy and contributes significantly to maternal and fetal morbidity and mortality. A protective hypercoagulable state is often developed during late pregnancy and can evolve into a prothrombotic state in patients with preeclampsia. The underlying mechanism of this prothrombotic transition remains poorly understood. We discuss recent progress in understanding the pathophysiology of preeclampsia and associated prothrombotic state.

RECENT FINDINGS

The hypercoagulable state developed during pregnancy is initiated by placental factors and progresses into the prothrombotic state in preeclampsia when the placenta is subjected ischemic and oxidative injuries. The cause of the preeclampsia-induced prothrombotic state is multifactorial, involving not only placental factors but also maternal conditions, which include genetic predisposition, preexisting medical conditions, and conditions acquired during pregnancy. Endotheliopathy is the primary pathology of preeclampsia and contributes to the prothrombotic state by inducing the dysregulation of coagulation, platelets, and adhesive ligands.

SUMMARY

Patients with preeclampsia often develop a severe prothrombotic state that predisposes them to life-threatening thrombosis and thromboembolism during and after pregnancy. Early recognition and treatment of this prothrombotic state can improve maternal and infant outcomes of preeclampsia patients.

Findings from a multicentre, observational study on reproductive outcomes in women with unexplained recurrent pregnancy loss: the OTTILIA registry

STUDY QUESTION

What evaluation and care is offered to women after unexplained recurrent pregnancy loss (RPL) or intra-uterine foetal death (IUFD) and what are the reproductive outcomes?

SUMMARY ANSWER

Women are assessed for thrombophilia and often treated with low-molecular weight heparin (LMWH) and/or low-dose aspirin (ASA).

WHAT IS KNOWN ALREADY

Randomized controlled trials (RCTs) on possible efficacy of heparins and/or aspirin have been inconclusive due to limited power to detect a difference and patient heterogeneity.

STUDY DESIGN, SIZE, DURATION

Prospective multicentre cohort study performed in 12 hospitals in three countries between 2012 and 2019.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All consecutive pregnant women with recurrent PL (≥3 losses or 2 losses in the presence of at least one euploid foetal karyotype) or at least one IUFD. Eligible women may have undergone thrombophilia testing before conception, at the discretion of local providers. The possible assignment of women to treatments (such as LMWH) was not decided a priori but was determined based on the responsible provider's current practice. Aims of the study were: (i) to evaluate factors associated with pregnancy outcome; (ii) to compare clinical management strategies in women with and without a subsequent successful pregnancy; and (iii) to evaluate characteristics of women who may benefit from antithrombotic therapy. A propensity score matching method was used to balance the differences in baseline characteristics.

MAIN RESULTS AND THE ROLE OF CHANCE

A matched sample of 265 pregnant women was analysed, with all undergoing thrombophilia screening; 103 out of 119 (86.6%) with and 98/146 (67.1%) without thrombophilia were prescribed with LMWH and/or ASA. Overall, live-births were recorded in 204 cases (77%), PL or IUFD in 61 (23%) pregnancies. Logistic regression showed a significant interaction between thrombophilia and treatment with LMWH (P = 0.03). Findings from sensitivity analysis showed odds ratio (OR) for pregnancy loss in women with inherited or acquired thrombophilia in absence of any treatment was 2.9 (95% CI, 1.4-6.1); the administration of LMWH (with or without ASA) was associated with higher odds of live-birth (OR, 10.6; 95% CI, 5.0-22.3). Furthermore, in women without thrombophilia, the odds of live-birth was significantly and independently associated with LMWH prophylaxis (alone or in association with ASA) (OR, 3.6; 95% CI, 1.7-7.9).

LIMITATIONS, REASONS FOR CAUTION

While the propensity score matching allows us to balance the differences in baseline characteristics, it does not eliminate all confounding.

WIDER IMPLICATIONS OF THE FINDINGS

Antithrombotic prophylaxis during pregnancy may be effective in women with otherwise unexplained PL or IUFD, and even more useful in those with thrombophilia.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by Italian Ministry of Health (Ricerca Corrente 2018-2020). Dr G.P. has received research grant support from Bristol Myers Squibb/Pfizer Alliance, Janssen, Boston Scientific Corporation, Bayer, and Portola and consultant fees from Amgen and Agile Therapeutics. Dr E.G. has received consultant fees from Italfarmaco and Sanofi. All other authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

NCT02385461.

Anticardiolipin Positivity Is Highly Associated With Intrauterine Growth Restriction in Women With Antiphospholipid Syndrome

The purpose of our study was to evaluate pregnancy outcomes of women with antiphospholipid antibodies (aPL) positivity and assess risk factors associated with adverse pregnancy outcomes. Pregnant women with aPL positivity were enrolled prospectively in China from January 2017 to March 2020. Treatment of low-dose aspirin and low molecular weight heparin were given. Pregnancy outcomes and coagulation function were recorded and compared with normal pregnancies. Multivariable logistic regression was performed to identify risk factors associated to intrauterine growth restriction (IUGR). 270 pregnant women, including 44 diagnosed as Antiphospholipid syndrome (APS), 91 as non-criteria APS (NCAPS) and 135 normal cases as control, were enrolled in the study. The live birth rate in aPL carriers and APS group was 97% and 95.5%, respectively. Adverse pregnancy outcomes did not show significant difference between aPL carriers and normal pregnancies, and between APS and NCAPS, except for IUGR. The incidence of IUGR was significantly higher in aPL carriers than normal pregnancies, and in APS patients than NCAPS (P < 0.05). After controlling for age, in vitro fertilization (IVF), pregnancy losses related to APS and treatment, anticardiolipin (aCL) positivity was the only variable significantly associated with IUGR, with an adjusted odds ratio of 4.601 (95% CI, 1.205-17.573). Better pregnant outcomes of aPL positive women, include APS and NCAPS, were achieved in our study with treatment based on low-dose aspirin (LDA) plus low molecular weight heparin (LMWH). The incidence of IUGR was still higher in them, and aCL positivity was the only one risk factor associated with IUGR.

Thrombophilia, Inflammation, and Recurrent Pregnancy Loss: A Case-Based Review

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies and is often multifactorial with the majority of miscarriages being due to aneuploidy and anatomic or physiological abnormalities. However, inherited or acquired thrombophilias have also been associated with RPL, albeit inconsistently. While inherited thrombophilias, such as factor V Leiden and prothrombin gene mutation, are relatively prevalent in women with RPL compared with the general population, a causal link has yet to be definitively established. Recently, systemic inflammation, as measured by high-sensitivity C-reactive protein, has also been hypothesized to play a role in infertility. Based on limited prospective trial data, antithrombotic therapy and antiplatelet agents have been proposed as possible tools for the prevention of RPL. Because of the multifactorial nature of RPL and infertility, various clinicians, as obstetricians and gynecologists, endocrinologists, hematologists, or vascular medicine specialists, may be requested to counsel these women. This, together with evidence gaps, frequently leads to distinctly different diagnostic and therapeutic recommendations, especially regarding thrombophilia testing and treatment. Using four case vignettes in this review, we critically appraise the literature and highlight how two clinicians from different subspecialties approach the relationship between RPL, inflammation, and thrombophilia.

Recurrent implantation failure - an overview of current research

BACKGROUND

Recurrent implantation failure (RIF) can be defined as a failure to achieve a clinical pregnancy after transfer of at least four embryos of good quality in a minimum of three fresh or frozen cycles in women under the age of 40. RIF is often a complex problem with a wide variety of etiologies and mechanisms as well as treatment options.

SUMMARY

Anatomical conditions of the uterus, thrombophilia, genetic abnormalities, or immunological factors are only a few examples which could be responsible for RIF. The recommendations for women with RIF vary depending on the source of their problem. There is not just one treatment option, but many depending on the etiology and the severity of the problem.

KEY MESSAGE

However, it would help to establish a set of standardized examinations and tests to use, in order to do a preliminary evaluation on each patient, which would then hopefully direct the approach of treatment for each individual couple.