Thrombophilia in pregnancy: a systematic review

Hypercoagulable states in arterial and venous thrombosis: When, how, and who to test?

Evaluation for underlying hypercoagulable states in patients with thrombosis is a frequent clinical conundrum. Testing for thrombophilias is often reflexively performed without strategic approach nor clear appreciation of the clinical implications of such results. Guidelines vary in the appropriate utilization of thrombophilia testing. In this review, we discuss the more commonly encountered inherited and acquired thrombophilias, their association with initial and recurrent venous thromboembolism, arterial thromboembolism, and role in women's health. We suggest an approach to thrombophilia testing guided by the clinical presentation, suspected pathophysiology, and an understanding of how such results may affect patient care.

The influence of specific mutations in the AT gene (SERPINC1) on the type of pregnancy related complications

BACKGROUND

Inherited antithrombin (AT) deficiency is a rare autosomal dominant disorder, caused by mutations in the SERPINC1 gene. The most common clinical presentation in AT deficient patients includes venous thrombosis and pulmonary embolism, while the association of AT deficiency and its effect on the development of pregnancy complications has been less studied. The aim of our research was to evaluate the effect of AT deficiency types, determined by genotyping, on pregnancy outcomes.

METHODS

A retrospective cohort study included 28 women with AT deficiency, and their 64 pregnancies were analyzed.

RESULTS

With regard to live birth rate, a significant difference was observed among women who were carriers of different SERPINC1 mutations, as the rate varied from 100% in cases of type I to the extremely low rate of 8% for women with type II HBS (AT Budapest 3) in the homozygous variant, P = 0.0005. All pregnancies from the type I group, even untreated ones, resulted in live births. In women with AT Budapest 3 in homozygous variant the overall live birth rate increased to 28.5% in the treated pregnancies. In this group the highest incidence of fetal death was observed of 62%; repeated fetal losses in 30%; fetal growth restriction in 22% and placental abruption in 7% of all pregnancies.

CONCLUSION

Our study results indicate a difference between type I and type II AT deficiency. The risk of pregnancy related VTE was equally present in both groups, except for AT Budapest 3 in the heterozygous variant, while adverse pregnancy outcomes were strictly related to type II, especially AT Budapest 3 in the homozygous variant.

Overcoming heparin resistance in pregnant women with antithrombin deficiency: a case report and review of the literature

Background

The risk of thromboembolic events during pregnancy in patients with antithrombin deficiency is increased. Preventing thromboembolic events during pregnancy in the case of antithrombin deficiency is still a matter of concern.

Case presentation

We present a case of a 19-year-old primigravida Greek Pomak woman, who was diagnosed as having congenital antithrombin deficiency. She had a history of recurrent miscarriages and a family history of thrombosis. She was managed with adjusted doses of low molecular weight heparin throughout her pregnancy, with regular anti-Xa and antithrombin level monitoring. Prior to delivery and for 4 days after delivery she received human antithrombin III concentrate. She delivered a small for gestational age baby with no other complications. She required an increased dose of heparin due to heparin resistance.

Conclusions

Antithrombin deficiency is associated with an increased risk of venous thromboembolic events with a 50% risk of thromboembolic events before the 50th year of life. It is a rare condition, so data concerning the optimal management during pregnancy are limited. The selection of patients who should receive low molecular weight heparin prophylaxis as well as dose intensity and monitoring are discussed. In our patient a conventional low molecular weight heparin dose proved to be inadequate at least at the laboratory level.

Vaginal antimycotics and the risk for spontaneous abortions

BACKGROUND

Spontaneous abortions are the most common complication of pregnancy. Clotrimazole and miconazole are widely used vaginal-antimycotic agents used for the treatment of vulvovaginal candidiasis. A previous study has suggested an increased risk of miscarriage associated with these azoles, which may lead health professionals to refrain from their use even if clinically indicated.

OBJECTIVE

The aim of the current study was to assess the risk for spontaneous abortions following first trimester exposure to vaginal antimycotics.

STUDY DESIGN

A historical cohort study was conducted including all clinically apparent pregnancies that began from January 2003 through December 2009 and admitted for birth or spontaneous abortion at Soroka Medical Center, Clalit Health Services, Beer-Sheva, Israel. A computerized database of medication dispensation was linked with 2 computerized databases containing information on births and spontaneous abortions. Time-varying Cox regression models were constructed adjusting for mother's age, diabetes mellitus, hypothyroidism, obesity, hypercoagulable or inflammatory conditions, recurrent miscarriages, intrauterine contraceptive device, ethnicity, tobacco use, and the year of admission.

RESULTS

A total of 65,457 pregnancies were included in the study: 58,949 (90.1%) ended with birth and 6508 (9.9%) with a spontaneous abortion. Overall, 3246 (5%) pregnancies were exposed to vaginal antimycotic medications until the 20th gestational week: 2712 (4.2%) were exposed to clotrimazole and 633 (1%) to miconazole. Exposure to vaginal antimycotics was not associated with spontaneous abortions as a group (crude hazard ratio, 1.11; 95% confidence interval, 0.96-1.29; adjusted hazard ratio, 1.11; 95% confidence interval, 0.96-1.29) and specifically for clotrimazole (adjusted hazard ratio, 1.05; 95% confidence interval, 0.89-1.25) and miconazole (adjusted hazard ratio, 1.34; 95% confidence interval, 0.99-1.80). Furthermore, no association was found between categories of dosage of vaginal antimycotics and spontaneous abortions.

CONCLUSION

Exposure to vaginal antimycotics was not associated with spontaneous abortions.

History of spontaneous miscarriage and the risk of diabetes mellitus among middle-aged and older Chinese women

AIMS

Epidemiological studies of the long-term maternal health outcomes of spontaneous miscarriages have been sparse and inconsistent. The objective of our study is to examine the association between spontaneous miscarriages and diabetes among middle-aged and older Chinese women.

METHODS

A total of 19,539 women from the Dongfeng-Tongji cohort study who completed a questionnaire and had medical examinations performed on were included in the analysis. History of spontaneous miscarriage was obtained by self-reporting in the first follow-up questionnaire interview. The presence of diabetes was determined by a fasting plasma glucose level, self-reported physician diagnosis and use of antidiabetic medication. A series of multivariate logistic regression models were used to calculate the odds ratios and 95% CI across spontaneous miscarriage categories (0, 1, 2, ≥ 3) after adjustment for potential confounding factors.

RESULTS

The prevalence rate of diabetes was 18.8% among the participants. In the fully adjusted logistic regression model, women who had 1, 2 or ≥ 3 spontaneous miscarriages had 0.86 times (95% CI 0.68, 1.08), 1.30 times (95% CI 0.82, 2.04) and 2.11 times (95% CI 1.08, 4.11) higher risk of diabetes, respectively, compared with women who had no history of spontaneous miscarriage.

CONCLUSIONS

There is an increased risk of diabetes among women with a history of a higher number of spontaneous miscarriages. History of multiple spontaneous miscarriages should be taken into consideration when assessing the risk of diabetes.

Antigenic binding sites of anti-protein S autoantibodies in patients with recurrent pregnancy loss

BACKGROUND

Protein S (PS) deficiency is a risk factor for adverse pregnancy outcomes including recurrent pregnancy loss. Several studies have shown that the presence of anti-PS autoantibodies (anti-PS) leads to an acquired PS deficiency. Hence, an epitope mapping study was conducted to know the pathogenesis of anti-PS in patients with recurrent pregnancy loss.

METHODS

PS was treated with thrombin to divide the protein into γ-carboxyglutamic acid (Gla) domain and Gla-domain free PS. For the preparation of fragments of epidermal growth factor (EGF)-like domains (EGF1-4), PS was subjected to proteolysis using lysyl endopeptidase. The epitopes were identified in immunoblot. Whether anti-PS recognized EGF family proteins in anti-PS-positive patients was also examined.

RESULTS

Anti-PS recognized Gla-domain free PS, especially the three fragments of EGF-like domains, EGF1-2, EGF3-4, and EGF1-4. Anti-PS recognized recombinant human EGF. Anti-PS and polyclonal antibodies to recombinant human EGF recognized PS in the absence of Ca2+ but not in the presence of Ca2+. In competitive inhibition studies, polyclonal antibodies to recombinant mouse EGF blocked anti-PS binding to PS in a concentration-dependent manner.

CONCLUSIONS

These results suggest that anti-PS in patients with recurrent pregnancy loss recognize EGF-like domains in PS. Interestingly, anti-PS also recognized EGF family proteins. Anti-PS in patients with recurrent pregnancy loss may be associated with not only thrombophilia but also the disruption of the EGF system.

Maternal Thrombophilia and Recurrent Miscarriage - Is There Evidence That Heparin is Indicated as Prophylaxis against Recurrence?

Background

Recurrent miscarriage, also referred to as recurrent spontaneous abortion (RSA), affects 1 – 5% of couples and has a multifactorial genesis. Acquired and congenital thrombophilia have been discussed as hemostatic risk factors in the pathogenesis of RSA.

Method

This review article was based on a selective search of the literature in PubMed. There was a special focus on the current body of evidence studying the association between RSA and antiphospholipid syndrome and hereditary thrombophilia disorders.

Results

Antiphospholipid syndrome (APS) is an acquired autoimmune thrombophilia and recurrent miscarriage is one of its clinical classification criteria. The presence of lupus anticoagulant has been shown to be the most important serologic risk factor for developing complications of pregnancy. A combination of low-dose acetylsalicylic acid and heparin has shown significant benefits with regard to pregnancy outcomes and APS-related miscarriage. Some congenital thrombophilic disorders also have an increased associated risk of developing RSA, although the risk is lower than for APS. The current analysis does not sufficiently support the analogous administration of heparin as prophylaxis against miscarriage in women with congenital thrombophilia in the same way as it is used in antiphospholipid syndrome. The data on rare, combined or homozygous thrombophilias and their impact on RSA are still insufficient.

Conclusion

In contrast to antiphospholipid syndrome, the current data from studies on recurrent spontaneous abortion do not support the prophylactic administration of heparin to treat women with maternal hereditary thrombophilia in subsequent pregnancies. Nevertheless, the maternal risk of thromboembolic events must determine the indication for thrombosis prophylaxis in pregnancy.

Preventing venous thromboembolism during pregnancy and postpartum: crossing the threshold

When should a patient with a known thrombophilia or prior venous thromboembolism (VTE) receive low-molecular-weight heparin (LMWH) prophylaxis during pregnancy and/or the postpartum period? Accurately predicting thrombotic and bleeding risks and knowing what to do with this information is at the heart of decision-making in these challenging scenarios. This article will explore the concept of a risk threshold from clinician and patient perspectives and provide guidance for the use of antepartum and postpartum LMWH prophylaxis in women with a known thrombophilia or prior VTE. Advice for the management of LMWH prophylaxis use around labor and delivery is also reviewed.

Differential haemostatic risk factors for pregnancy-related deep-vein thrombosis and pulmonary embolism

Limited data exist on thrombophilia and the risk of venous thrombosis (VT) during pregnancy and postpartum. The objectives of the present study were to investigate the role of haemostatic risk factors for pregnancy-related VT and their phenotypic expression in deep-vein thrombosis (DVT) and pulmonary embolism (PE). Total 313 cases with objectively verified first time VT and 353 controls were selected from a source population of 377,155 women with 613,232 pregnancies. The adjusted odds ratio (aOR) for pregnancy-related VT was 1.7 (95% confidence interval [CI] 1.1–2.8) for women with factor VIII >90th percentile. The aOR for VT for endogenous thrombin potential and D-dimer values >90thpercentiles were 1.8 (95% CI 1.1–3.0) and 2.1 (95% CI 1.3–3.3), respectively. Factor IX >90thpercentile or free protein S ≤the 5th percentile increased the risk for PE, and the aORs were 2.4 (95% CI 1.1–5.0) and 3.1 (95% CI 1.3–7.2), respectively. Women carrying the factor V Leiden (F5 rs6025) polymorphism, or who had reduced sensitivity to activated protein C (aPC) in the absence of F5 rs6025, had increased risk for DVT, with unadjusted ORs 7.7 (95% CI 4.7–12.7) and 3.5 (95% CI 2.2–5.4), respectively. Women with a history of pregnancy-related VT showed activation of coagulation and had elevated factor VIII. Furthermore, high levels of factor IX and low levels of free protein S were associated with increased risk for PE, whereas aPC resistance and F5 rs6025 were risk factors for DVT and not PE.

Evolution of Factor V Leiden

Factor V Leiden is a procoagulant mutation associated with venous and arterial thrombosis and pregnancy complications. Its high prevalence of 5% in Caucasians suggests that there are evolutionary benefits as well. Carriers are indeed reported to have various advantageous phenotypes related to haemostasis, inflammation and fertility: less acute blood loss; less menstrual blood loss; decreased risk of intracranial haemorrhage; milder phenotypes of haemophilia; higher survival in and lower susceptibility to severe sepsis; higher survival in acute respiratory distress syndrome; less severe diabetic nephropathy and higher fecundity in both men and women. Not all these associations come from high quality adequately powered studies and many have not been confirmed by further research. The evolutionary influence of the alleged associations varies and is difficult to establish, partly due to a shift over time in risk factors of the diseases concerned. For most of the phenotypes possible mechanistic explanations can be provided. The procoagulant phenotype and perhaps also certain pregnancy complications follow from activated protein C (APC) resistance. Elevated APC levels possibly mediate anti-inflammatory effects. Higher sperm counts and more successful embryo implantation seem to play a role in the increased fecundity.

Obstetric complications and pregnancy-related venous thromboembolism: The effect of low-molecular-weight heparin on their prevention in carriers of factor V Leiden or prothrombin G20210A mutation

Whether the administration of low-molecular-weight heparin (LMWH) during pregnancy is effective in preventing obstetric complications and pregnancy-related venous thromboembolism (VTE) in women who are carriers of factor V Leiden (FVL) and/or prothrombin variant G20210A (PTm) is controversial. This observational study investigated the possible efficacy of pharmacological treatment with LMWH ± aspirin (ASA) in pregnancy outcomes in 1,011 pregnancies of 416 women with thrombophilia (FVL and/or PTm). Most patients were chosen on the basis of previous obstetrical complications (36%), or because of familial or personal history of venous/arterial thromboembolism (28% and 18%, respectively); 74 patients (18%) were incidentally identified. The outcome was evaluated according to the type of treatment and of the period of pregnancy when the treatment was started. After adjustment for observation before and after diagnosis of thrombophilia, previous miscarriages and VTE, parity, age and centre, we observed that LMWH had a protective effect on miscarriages (odds ratio [OR] 0.52, 95% confidence interval [CI] 0.29–0.94) and VTE (OR 0.05, 95% CI 0.01–0.21). ASA appeared to have no effect on the prevention of obstetric complications and VTE. A nested analysis performed in 116 women with two or more obstetric complications confirmed that the highest number of live births was recorded in the group under LMWH prophylaxis (OR 0.19, 95% CI 0.05–0.75). These results suggest that LMWH prophylaxis reduces the risk of obstetric complications in carriers of FVL and/or PTm, particularly in those with previous obstetric events. Furthermore, LMWH prophylaxis reduces the risk of pregnancy-related VTE.

Diagnosis and management of non-criteria obstetric antiphospholipid syndrome

Accurate diagnosis of obstetric antiphospholipid syndrome (APS) is a prerequisite for optimal clinical management. The international consensus (revised Sapporo) criteria for obstetric APS do not include low positive anticardiolipin (aCL) and anti β2 glycoprotein I (aβ2GPI) antibodies (> 99th centile) and/or certain clinical criteria such as two unexplained miscarriages, three non-consecutive miscarriages, late preeclampsia, placental abruption, late premature birth, or two or more unexplained in vitro fertilisation failures. In this review we examine the available evidence to address the question of whether patients who exhibit non-criteria clinical and/or laboratory manifestations should be included within the spectrum of obstetric APS. Prospective and retrospective cohort studies of women with pregnancy morbidity, particularly recurrent pregnancy loss, suggest that elimination of aCL and/or IgM aβ2GPI, or low positive positive aCL or aβ2GPI from APS laboratory diagnostic criteria may result in missing the diagnosis in a sizeable number of women who could be regarded to have obstetric APS. Such prospective and retrospective studies also suggest that women with non-criteria obstetric APS may benefit from standard treatment for obstetric APS with low-molecular-weight heparin plus low-dose aspirin, with good pregnancy outcomes. Thus, non-criteria manifestations of obstetric APS may be clinically relevant, and merit investigation of therapeutic approaches. Women with obstetric APS appear to be at a higher risk than other women of pre-eclampsia, placenta- mediated complications and neonatal mortality, and also at increased long-term risk of thrombotic events. The applicability of these observations to outcomes in women with non-criteria obstetric APS remains to be determined.

Thrombin generation and low-molecular-weight heparin prophylaxis in pregnant women with thrombophilia

Pregnancy is associated with increased risk of venous thromboembolism, especially in the presence of thrombophilia. However, there is no consensus on the optimal approach for thromboprophylaxis in this population. Recent evidence suggests that thrombin generation correlates with the overall procoagulant state of the plasma. Our aim was to evaluate thrombin generation in a prospective cohort of thrombophilic pregnant women, and investigate the effectiveness of low-molecular- weight heparin (LMWH) prophylaxis in pregnancy. Women with severe (n=8), mild (n=47) and no (n=15) thrombophilia were followed throughout their pregnancies. Thrombin generation was evaluated in each trimester as well as five days and eight weeks postpartum (as a reference category). In women undergoing LMWH prophylaxis, thrombin generation and anti-Factor-Xa activity were measured just before and 4 hours after administration (peak effect). Thrombin generation was determined using Technothrombin TGA assay system. For the analysis, median peak thrombin and endogenous thrombin potential were used. Peak thrombin and endogenous thrombin potential were increased during pregnancy compared to the non-pregnant state with the highest results in the severe thrombophilia group. In women receiving LMWH prophylaxis a decrease was observed in thrombin generation at peak effect but over the progression of pregnancy the extent of this decrease reduced in a stepwise fashion. Our results show that thrombin generation demonstrates the hypercoagulable state in thrombophilic pregnancies. In addition, we found the effect of LMWH prophylaxis to progressively decrease with advancing stages of pregnancy.

Prevalence of F5 1691G>A, F2 20210G>A, and MTHFR 677C>T polymorphisms in Bosnian women with pregnancy loss

The relationship between genetic risk factors of thrombophilia and pregnancy loss (PL) is being discussed. The focus has been on F5 1691G>A, F2 20210G>A, and MTHFR 677C>T polymorphisms that may predispose women to microthrombosis during the stages of embryo implantation and placentation. Although, the frequencies of these polymorphisms were reported in different populations, such studies have not yet been performed in Bosnian population. In this study, we determined the prevalence of F5 G>A (rs6025), F2 G>A (rs1799963) and MTHFR C>T (rs1801133) polymorphisms in Bosnian women. A total of 154 women with PL, mean age 33 (±5.4) years, were enrolled in the study. As a control group, 154 mothers [mean age 31.4 (±6.7) years] with at least one live-born child were included. We used real-time polymerase chain reaction (PCR) to determine the frequencies of F5 G>A and F2 G>A genotypes, and PCR-restriction fragment length polymorphism (RFLP) for analyzing MTHFR C>T genotypes. The frequency of heterozygotes for F5 and F2 was significantly higher in women with venous thrombosis (VT) compared to women without VT (p = 0.047 and p = 0.001, respectively). There was no significant difference in the distribution of MTHFR genotypes and alleles between these two groups. In addition, we observed no significant differences in the genotype and allele frequencies between the group with PL and control group, for all investigated polymorphisms. The allele frequencies for 1691A (F5), 20210A (F2), and 677T (MTHFR) reported in this study are consistent with the data obtained for other European countries, however, we were not able to confirm the association between the three polymorphisms and PL in Bosnian women.

The physiologic anticoagulant and anti-inflammatory role of heparins and their utility in the prevention of pregnancy complications

Accumulating evidence supports the concept of increased thrombin generation, placental vascular lesions, and inflammation as crucial points in the development of the great obstetrical syndromes [preeclampsia, intrauterine growth restriction (IUGR), preterm labor (PTL), preterm prelabor rupture of membranes (PROM), fetal demise and recurrent abortions]. In light of this, the role of heparins for primary or secondary prevention of these syndromes is becoming more and more apparent, mainly due to the antithrombotic and anti-inflammatory effects of heparins. There is agreement regarding the use of heparin in the prevention of gestational complications in patients with antiphospholipid syndrome, while its use for other obstetrical complications is under debate. In the present review we will describe the physiologic role of heparins on coagulation and inflammation and we will discuss current evidence regarding the use of heparins for the prevention/ treatment of obstetrical syndromes.

Pregnancy, thrombophilia, and the risk of a first venous thrombosis: systematic review and bayesian meta-analysis

Objective To provide evidence to support updated guidelines for the management of pregnant women with hereditary thrombophilia in order to reduce the risk of a first venous thromboembolism (VTE) in pregnancy.Design Systematic review and bayesian meta-analysis.Data sources Embase, Medline, Web of Science, Cochrane Library, and Google Scholar from inception through 14 November 2016.Review methods Observational studies that reported on pregnancies without the use of anticoagulants and the outcome of first VTE for women with thrombophilia were eligible for inclusion. VTE was considered established if it was confirmed by objective means, or when the patient had received a full course of a full dose anticoagulant treatment without objective testing. Results 36 studies were included in the meta-analysis. All thrombophilias increased the risk for pregnancy associated VTE (probabilities ≥91%). Regarding absolute risks of pregnancy associated VTE, high risk thrombophilias were antithrombin deficiency (antepartum: 7.3%, 95% credible interval 1.8% to 15.6%; post partum: 11.1%, 3.7% to 21.0%), protein C deficiency (antepartum: 3.2%, 0.6% to 8.2%; post partum: 5.4%, 0.9% to 13.8%), protein S deficiency (antepartum: 0.9%, 0.0% to 3.7%; post partum: 4.2%; 0.7% to 9.4%), and homozygous factor V Leiden (antepartum: 2.8%, 0.0% to 8.6%; post partum: 2.8%, 0.0% to 8.8%). Absolute combined antepartum and postpartum risks for women with heterozygous factor V Leiden, heterozygous prothrombin G20210A mutations, or compound heterozygous factor V Leiden and prothrombin G20210A mutations were all below 3%. Conclusions Women with antithrombin, protein C, or protein S deficiency or with homozygous factor V Leiden should be considered for antepartum or postpartum thrombosis prophylaxis, or both. Women with heterozygous factor V Leiden, heterozygous prothrombin G20210A mutation, or compound heterozygous factor V Leiden and prothrombin G20210A mutation should generally not be prescribed thrombosis prophylaxis on the basis of thrombophilia and family history alone. These data should be considered in future guidelines on pregnancy associated VTE risk.

Hereditary Thrombophilia and Recurrent Pregnancy Loss

The challenging nature of recurrent pregnancy loss (RPL) is multifactorial, but largely begins with determining who meets diagnostic criteria for RPL as definitions vary and frequently change. Many patients seek obstetrical intervention after losses, even if they do not meet the criteria for RPL, and even those strictly meeting criteria often present a conundrum as to the etiology of their condition. The contribution of hereditary thrombophilia to RPL, the impact of each disorder on the clotting cascade, available evidence regarding pregnancy outcomes, and current recommendations for evaluation and treatment is presented.

Genetic Causes of Recurrent Pregnancy Loss

Pregnancy loss is one of the most common obstetric complications, affecting over 30% of conceptions. A considerable proportion of losses are due to genetic abnormalities. Indeed, over 50% of early pregnancy losses have been associated with chromosomal abnormalities. Most are due to de novo nondisjunctional events but balanced parental translocations are responsible for a small but important percentage of genetic abnormalities in couples with recurrent pregnancy loss. In the past, assessment of genetic abnormalities was limited to karyotype performed on placental or fetal tissue. However, advances in molecular genetic technology now provide rich genetic information about additional genetic causes of and risk factors for pregnancy loss. In addition, the use of preimplantation genetic testing in couples undergoing in vitro fertilization has the potential to decrease the risk of pregnancy loss from genetic abnormalities. To date, efficacy is uncertain but considerable potential remains. This chapter will review what is known about genetic causes of recurrent pregnancy loss with a focus on novel causes and potential treatments. Remaining knowledge gaps will be highlighted.

Immunologic Abnormalities, Treatments, and Recurrent Pregnancy Loss: What Is Real and What Is Not?

Recurrent pregnancy loss, depending on the definition, affects 1% to 3% of women aiming to have a child. Little is known about the direct causes of recurrent pregnancy loss, and the condition is considered to have a multifactorial and complex pathogenesis. The aim of this review was to summarize the evaluation and the management of the condition with specific emphasis on immunologic biomarkers identified as risk factors as well as current immunologic treatment options. The review also highlights and discusses areas in need of further research.

Gender related issues in thrombosis and hemostasis

INTRODUCTION

Many aspects of hemostasis, both primary and secondary, as well as fibrinolysis display sex differences. From a clinical viewpoint, certain differential phenotypic presentations clearly arise within various disorders of thrombosis and hemostasis. Areas covered: The present mini-review summarizes selected clinical entities where sex differences are reflected in both frequency and clinical presentation of hemostasis disorders. Sex differences are discussed within the settings of cardiovascular disease, including coronary artery disease and ischemic stroke, venous thromboembolism and inherited bleeding disorders. Moreover, pregnancy and labor present particular challenges in terms of increased thromboembolic and bleeding risk, and this is also summarized. Expert commentary: Available knowledge on sex differences in risk factors and clinical presentation of disorders within thrombosis and hemostasis is increasing. However, more evidence is needed to further clarify different risk factors and treatment effect in men and women, both as regards to cardiovascular disease and venous thromboembolism. This should facilitate improved gender guided risk stratification, and prevention and treatment of these diseases. Finally, risk assessment during pregnancy remains a challenge; this applies both to thromboembolic risk assessment during normal pregnancy and special care of women with inherited bleeding disorders during labor.

A case that illustrates the challenges of managing pregnant patients with antithrombin deficiency: More questions than answers

Using an illustrative case of a patient with antithrombin (AT) deficiency who developed a recurrent venous thromboembolism (VTE) in pregnancy despite therapeutic low-molecular-weight heparin (LMWH), we highlight what is known in the literature and address areas of controversy through a series of questions around the case. The questions we address include the role of anti-Xa monitoring for patients with past VTE on antepartum LMWH, what treatment regimen is recommended for pregnant patients who develop a recurrent VTE while on therapeutic anticoagulation, the role of antepartum AT concentrate prophylaxis, and the management of labor/delivery, epidural anesthesia and postpartum anticoagulation. We also describe practical considerations for use of AT concentrate, including teaching our patient to self-infuse AT concentrate at home with support of a hemophilia treatment center (HTC), and the direct and indirect costs of AT concentrate for secondary prophylaxis.

Thrombophilic gene polymorphisms and recurrent pregnancy loss in Greek women

INTRODUCTION

Recurrent pregnancy loss (RPL) is a multifactorial disorder. The aim of this study was the detection of various genetic polymorphisms and their correlation to RPL, in Greek women.

METHODS

The impact of 12 thrombophilic polymorphisms was evaluated, among 48 Greek women with a history of RPL, vs 27 healthy parous women. Multiplex PCR and in situ hybridization on nitrocellulose films were performed, to investigate 12 genetic polymorphisms previously reported as risk factors for RPL.

RESULTS

Heterozygous FV Leiden, homozygous PAI-1 4G/4G, heterozygous MTHFR C677T, homozygous MTHFR A1298C, as much as the combined thrombophilic genotypes MTHFR 677T + ACE Ι/D, MTHFR 677T/1298C + ACE D/D, ACE I/D + b-fibrinogen -455 G/A, FV HR2 + b-fibrinogen -455 G/A showed a correlation as risk factors for RPL, whereas the rest of the investigated polymorphisms and their combinations did not render statistically significant differences between the two groups in study.

CONCLUSION

The results of this study, as well as those of similar studies, concerning the detection of genetic, environmental, and physiological factors underlying RPL, will prove of critical significance in the investigation and treatment of thrombophilic predisposition, in cases of RPL.

Anticoagulants to prevent recurrent placenta-mediated pregnancy complications: Is it time to put the needles away?

Placenta-mediated pregnancy complications, such as pre-eclampsia, placental abruption, birth of a small-for-gestational age infant and late pregnancy loss, are common and carry significant morbidity and mortality. The etiology of placenta-mediated pregnancy complications is likely multifactorial and may include abnormal coagulation activation of the maternal-fetal interface. The use of antepartum low-molecular-weight heparin (LMWH) prophylaxis to prevent recurrent placenta-mediated pregnancy complications has become common practice despite limited and conflicting evidence to support its use. This paper reviews the evidence, including recently published data from an individual patient level meta-analysis, which challenges the role of LMWH in preventing recurrent placenta-mediated pregnancy complications. Incorporating this recent evidence, we recommend against the use of LMWH to prevent recurrent placenta-mediated pregnancy complications in women with and without inherited thrombophilia.

Antiphospholipid antibody profile based obstetric outcomes of primary antiphospholipid syndrome: the PREGNANTS study

BACKGROUND

Antiphospholipid syndrome is an autoimmune, hypercoagulable state that is caused by antiphospholipid antibodies. Anticardiolipin antibodies, anti-β2 glycoprotein-I, and lupus anticoagulant are the main autoantibodies found in antiphospholipid syndrome. Despite the amassed body of clinical knowledge, the risk of obstetric complications that are associated with specific antibody profile has not been well-established.

OBJECTIVE

The purpose of this study was to assess the risk of obstetric complications in women with primary antiphospholipid syndrome that is associated with specific antibody profile.

STUDY DESIGN

The Pregnancy In Women With Antiphospholipid Syndrome study is a multicenter, retrospective, cohort study. Diagnosis and classification of antiphospholipid syndrome were based on the 2006 International revised criteria. All women included in the study had at least 1 clinical criteria for antiphospholipid syndrome, were positive for at least 1 antiphospholipid antibody (anticardiolipin antibodies, anti-β2 glycoprotein-I, and/or lupus anticoagulant), and were treated with low-dose aspirin and prophylactic low molecular weight heparin from the first trimester. Only singleton pregnancies with primary antiphospholipid syndrome were included. The primary outcome was live birth, defined as any delivery of a live infant after 22 weeks gestation. The secondary outcomes were preeclampsia with and without severe features, intrauterine growth restriction, and stillbirth. We planned to assess the outcomes that are associated with the various antibody profile (test result for lupus anticoagulant, anticardiolipin antibodies, and anti-β2 glycoprotein-I).

RESULTS

There were 750 singleton pregnancies with primary antiphospholipid syndrome in the study cohort: 54 (7.2%) were positive for lupus anticoagulant only; 458 (61.0%) were positive for anticardiolipin antibodies only; 128 (17.1%) were positive for anti-β2 glycoprotein-I only; 90 (12.0%) were double positive and lupus anticoagulant negative, and 20 (2.7%) were triple positive. The incidence of live birth in each of these categories was 79.6%, 56.3%, 47.7%, 43.3%, and 30.0%, respectively. Compared with women with only 1 antibody positive test results, women with multiple antibody positive results had a significantly lower live birth rate (40.9% vs 56.6%; adjusted odds ratio, 0.71; 95% confidence interval, 0.51-0.90). Also, they were at increased risk of preeclampsia without (54.5% vs 34.8%; adjusted odds ratio, 1.56; 95% confidence interval, 1.22-1.95) and with severe features (22.7% vs 13.8%, adjusted odds ratio, 1.66; 95% confidence interval, 1.19-2.49), of intrauterine growth restriction (53.6% vs 40.8%; adjusted odds ratio, 2.31; 95% confidence interval, 1.17-2.61) and of stillbirth (36.4% vs 21.7%; adjusted odds ratio, 2.67; 95% confidence interval, 1.22-2.94). In women with only 1 positive test result, women with anti-β2 glycoprotein-I positivity present alone had a significantly lower live birth rate (47.7% vs 56.3% vs 79.6%; P<.01) and a significantly higher incidence of preeclampsia without (47.7% vs 34.1% vs 11.1%; P<.01) and with severe features (17.2% vs 14.4% vs 0%; P=.02), intrauterine growth restriction (48.4% vs 40.1% vs 25.9%; P<.01), and stillbirth (29.7% vs 21.2% vs 7.4%; P<.01) compared with women with anticardiolipin antibodies and with women with lupus anticoagulant present alone, respectively. In the group of women with >1 antibody positivity, triple-positive women had a lower live birth rate (30% vs 43.3%; adjusted odds ratio,0.69; 95% confidence interval, 0.22-0.91) and a higher incidence of intrauterine growth restriction (70.0% vs 50.0%; adjusted odds ratio,2.40; 95% confidence interval, 1.15-2.99) compared with double positive and lupus anticoagulant negative women.

CONCLUSION

In singleton pregnancies with primary antiphospholipid syndrome, anticardiolipin antibody is the most common sole antiphospholipid antibody present, but anti-β2 glycoprotein-I is the one associated with the lowest live birth rate and highest incidence of preeclampsia, intrauterine growth restriction, and stillbirth, compared with the presence of anticardiolipin antibodies or lupus anticoagulant alone. Women with primary antiphospholipid syndrome have an increased risk of obstetric complications and lower live birth rate when <1 antiphospholipid antibody is present. Despite therapy with low-dose aspirin and prophylactic low molecular weight heparin, the chance of a liveborn neonate is only 30% for triple-positive women.

'To test or not to test', the arguments for and against thrombophilia testing in obstetrics

Clinicians increasingly investigate women for thrombophilias due to their associations with venous thromboembolism and placenta-mediated pregnancy complication. These associations, however, are modest and based largely on retrospective data from studies with heterogeneous classifications and populations, leading to discordance between evidence and guidelines. Current evidence suggests a contributory rather than causative role for thrombophilia in placenta-mediated pregnancy complication and venous thromboembolism. With little evidence of benefit from antithrombotic therapy in placenta-mediated pregnancy complication, thrombophilia screening remains controversial. Given the low absolute risk of placenta-mediated pregnancy complication and gestational venous thromboembolism with heritable thrombophilia, universal screening is inappropriate. Selective screening for antiphospholipid syndrome is supported by robust evidence of benefit. Conversely, selective screening for heritable thrombophilia has not been shown to effectively manage placenta-mediated pregnancy complication. Therefore, at present heritable thrombophilia screening is not warranted for placenta-mediated pregnancy complication. Until we have better evidence from better stratified patient groups, caution should remain if we wish to practice evidence-based medicine.

Comparison of two preventive treatments for patients with recurrent miscarriages carrying a C677T methylenetetrahydrofolate reductase mutation: 5-year experience

Objective

To investigate the effect of anticoagulant treatment on pregnancy outcomes in patients with previous recurrent miscarriages (RM) who carry a methylenetetrahydrofolate reductase (MTHFR) gene mutation.

Methods

In this longitudinal retrospective study, patients with RM were treated during pregnancy with either: (i) 100 mg/day aspirin and 5 mg/day folic acid (group 1); or the same protocol plus 0.4 mg/day enoxaparin (group 2). An age-matched group of triparous women without RM or thrombophilia was used as the control group (group 3).

Results

This study enrolled 246 women with RM (123 per treatment group) and age-matched controls (n = 117). The delivery rate was significantly lower in group 1 than group 2 (46.3% versus 79.7%, respectively). The miscarriage rate was significantly lower in group 2 compared with group 1 (20.3% versus 51.2%, respectively). In the control group 3, the delivery rate was 86.3% and the miscarriage rate was 12.8%.

Conclusion

Treatment with low-dose aspirin, enoxaparin and folic acid was the most effective therapy in women with RM who carried a C677T MTHFR mutation.

Management of Venous Thromboembolism in Patients with Hereditary Antithrombin Deficiency and Pregnancy: Case Report and Review of the Literature

Background. Hereditary antithrombin deficiency is a thrombogenic disorder associated with a 50–90% lifetime risk of venous thromboembolism (VTE), which is increased during pregnancy and the puerperium in these patients. We present a case of a woman with antithrombin (AT) deficiency who presented with a VTE despite therapeutic low molecular weight heparin (LMWH). Though the pregnancy was deemed unviable, further maternal complications were mitigated through the combined use of therapeutic anticoagulation and plasma-derived antithrombin concentrate infusions to normalize her functional antithrombin levels. Methods. A review of the literature was conducted for studies on prophylaxis and management of VTE in pregnant patients with hereditary AT deficiency. The search involved a number of electronic databases, using combinations of keywords as described in the text. Only English language studies between 1946 and 2015 were included. Conclusion. Antithrombin concentrate is indicated in pregnant women with hereditary AT deficiency who develop VTE despite being on therapeutic dose anticoagulation. Expert opinion suggests AT concentrate should be used concomitantly with therapeutic dose anticoagulation. However, further high-quality studies on the dose and duration of treatment in the postpartum period are required. Use of AT concentrate for prophylaxis is controversial and should be based on individual VTE risk stratification.

Thrombophilia Screening: Universal, Selected, or Neither?

The utility of thrombophilia testing in clinical practice is still a matter of debate because studies have not shown a benefit in the reduction of recurrent venous thromboembolism (VTE) risk in patients with thrombosis, despite the clearly higher VTE risk for first thrombosis. Screening for thrombophilia is indicated in selected patients. Particularly in selected young patients, especially women of childbearing age, the knowledge of the genetic thrombophilic defect may help in specific situations to decrease the risk of VTE events. Avoidance of modifiable risk factors and/or prophylactic thromboembolic procedures may be evaluated in selected patients. A comprehensive workup including personal and familial history, clinical examination, and laboratory test results including hereditary thrombophilia remains helpful in assessing the cumulative risk and the management of this group of selected patients.

Association of Methylenetetrahydrofolate Reductase C677T and A1298C Gene Polymorphisms With Recurrent Pregnancy Loss in Syrian Women

C677T polymorphism of the methylenetetrahydrofolate reductase ( MTHFR) gene was a risk factor for recurrent pregnancy loss (RPL), but few studies have confirmed a possible role of MTHFR A1298C polymorphism in RPL risk. This study was carried out to determine the influence of the MTHFR gene polymorphisms in RPL Syrian women. A case-control study was performed on 2 groups (106 healthy and 100 RPL women). The frequency of the MTHFR gene polymorphisms was determined by polymerase chain reaction based on restriction fragment length gene polymorphism. In the RPL group, the genotype frequencies of MTHFR C677T were CC (41%), CT (41%), and TT (18%), and in the control group, the frequencies were CC (62.2%), CT (36.7%), and TT (1%). Statistical analysis showed a homozygous TT genotype and T allele were significantly different in the RPL group ( P = .000003 and P = .000019, respectively). The genotype frequencies of MTHFR A1298C were AA (53%), AC (44%), and CC (8%) in the RPL group, whereas in the control group, these were AA (61.3%), AC (37.8%), and CC (1%). A significant difference in the CC genotype and C allelic frequencies in the RPL women was observed ( P = .014 and P = .064, respectively). The patients having compound heterozygous (677 CT/1298AC) were associated with an estimated 4.86-fold increase in risk of pregnancy loss compared to individuals with a wild type ( P = .012). Our findings indicate that RPL women with homozygous genotype for (C677T and A1298C) either alone or compound heterozygous genotypes have a high risk of pregnancy loss in Syrian women.

Inherited thrombophilia: a double-edged sword

Inherited thrombophilia is a blood coagulation disorder that increases the risk for venous thromboembolism (VTE). During the last decades, the practice of testing has evolved from testing selected populations, leading to high perceived risks, to broad testing for various conditions that included VTE, arterial thrombosis, and pregnancy complications. Because results of such tests usually do not guide treatment decisions, not testing patients with VTE for inherited thrombophilia is on the "Choosing Wisely" list endorsed by multiple specialty societies, including ASH. Inherited thrombophilia can be regarded a double-edged sword, as despite the rationale not to test, it is still being performed frequently. Another way of seeing inherited thrombophilia as a double-edged sword lies in its 2-sided association with reproduction, both in men and in women. Current areas of research are whether women with inherited thrombophilia and pregnancy complications benefit from anticoagulant therapy with regard to improving the chance of a successful pregnancy. Potential effects of inherited thrombophilia, most notably factor V Leiden, on improved embryo implantation in women and sperm counts in men are intriguing, but are currently poorly understood.

Pregnancy outcome after a first episode of cerebral vein thrombosis

Essentials Little is known about recurrences and pregnancy outcome after cerebral vein thrombosis (CVT). We studied a cohort of pregnant women with CVT. Women with CVT appear at increased risk of late obstetrical complications despite prophylaxis. Risks of recurrent thrombosis and bleeding in women on heparin prophylaxis while pregnant are low.

SUMMARY

Background The risk of recurrent thrombosis and bleeding episodes in women with previous cerebral vein thrombosis (CVT) on antithrombotic prophylaxis with low-molecular-weight heparin (LMWH) during pregnancy is not established and little information is available on pregnancy outcome. Objectives The aims of this study were to evaluate the risk of obstetrical complications, recurrent venous thrombosis and bleeding in a cohort of pregnant women on LMWH after a first episode of CVT. In addition, to estimate the relative risk of obstetrical complications, patients were compared with healthy women without thrombosis and with at least one pregnancy in their life. Patients We studied a cohort of 52 patients and 204 healthy women. Results The risk of developing late obstetrical complications was 24% (95% CI, 18-38%), leading to a relative risk of 6.09 (95% CI, 2.46-15.05). The risk of miscarriage was not increased. The higher risk of late obstetrical complications in patients appeared unrelated to a previous history of obstetrical complications, to the carriership of thrombophilia abnormalities, or to the presence of co-morbidities. The incidence of termination observed in patients with thrombophilia was double that observed in those without. No recurrent thrombosis or bleeding episodes were observed. Conclusions Women with previous CVT on LMWH prophylaxis during pregnancy have a low risk of developing recurrent thrombosis or bleeding episodes, but seem to have an increased risk of late obstetrical complications.

Associations of recurrent miscarriages with chromosomal abnormalities, thrombophilia allelic polymorphisms and/or consanguinity in Saudi Arabia

BACKGROUND

Recurrent pregnancy loss (RPL) or recurrent spontaneous abortion is an obstetric complication that affects couples at reproductive age. Previous reports documented a clear relationship between parents with chromosomal abnormalities and both recurrent miscarriages and infertility. However, limited data is available from the Arabian Peninsula which is known by higher rates of consanguineous marriages. The main goal of this study was to determine the prevalence of chromosomal abnormalities and thrombophilic polymorphisms, and to correlate them with RPL and consanguinity in Saudi Arabia.

METHODS

Cytogenetic analysis of 171 consent patients with RPL was performed by the standard method of 72-h lymphocyte culture and GTG banding. Allelic polymorphisms of three thrombophilic genes (Factor V Leiden, Prothrombin A20210G, MTHFR C677T) were performed using PCR-RFLP (restriction fragment length polymorphism) and gel electrophoresis.

RESULTS

Data analysis revealed that 7.6 % of patients were carrier of numerical or structural chromosomal abnormalities. A high rate of translocations (46 %) was associated to increased incidence of RPL. A significant correlation between consanguineous RPL patients and chromosomal abnormalities (P < 0.05) was found. Both Factor V Leiden and Prothrombin A20210G allelic polymorphisms were significantly associated with a higher prevalence of RPL.

CONCLUSIONS

This study demonstrated a strong association between RPL and the prevalence of chromosomal abnormalities and inherited thrombophilia. Given the high rate of consanguineous marriages in the Saudi population, these results underline the importance of systematic cytogenetic investigation and genetic counseling preferably at the premarital stage or at least during early pregnancy phase through preimplantation genetic diagnosis (PGD).

A Review of Hormonal Contraception and Venous Thromboembolism in Adolescents

BACKGROUND

The number of adolescents who are prescribed hormonal contraception (HC) for contraceptive and noncontraceptive indications is increasing. Approximately 1 of 4 female adolescents will use some form of HC by age 19 years. Venous thromboembolism (VTE) is a rare, but life-threatening complication associated with HC use. Although adolescents aged 15 to 19 years have the lowest absolute HC-associated VTE risk, they still account for 5.9% of HC-associated VTE. The absolute HC-associated VTE risk for those younger than 15 years of age is not well described.

OBJECTIVE

The objectives of this report are to describe the current literature regarding HC-associated VTE in adolescents, to review the coagulation cascade and in vivo coagulation, to highlight differences between the adolescent and adult coagulation profiles, to discuss coagulation profile changes related to HC use, and to identify knowledge deficits for future study.

CONCLUSION

The mechanisms and confounding variables that lead to HC-associated VTE in all adolescents are not well understood because many large HC studies exclude female adolescents younger than 18 years of age. Because of the paucity of data in this age group, observational studies and randomized controlled trials of VTE risk in adolescents on varying forms of HC are needed. Studies should include female adolescents across the entire adolescent age span (12-21 years) to better understand HC-associated VTE risk in this population.

Birthweight in pregnant women with protein S deficiency treated with low-molecular-weight heparin: a retrospective cohort study

OBJECTIVE

To determine the risk of small-for-gestational-age (SGA) and intrauterine growth retardation (IUGR) in pregnant women with protein S (PS) deficiency who received low-molecular-weight heparin (LMWH).

METHODS

Retrospective cohort study of pregnant women seen from January 2002 to December 2011. The study cohort comprised a total of 328 patients with PS deficiency, who received prophylactic enoxaparin during pregnancy. The control cohort included 11 884 pregnant women without significant past medical history. The risk of SGA and IUGR was calculated as odds ratio. Multivariate regression analysis over the entire reference population was performed determining the risk of both SGA and IUGR by adjusting for maternal age, first delivery, maternal underweight status, pre-eclampsia, other treated thrombophilias or history of recurrent abortion.

RESULTS

The SGA rates in the PS deficiency and control cohorts were 10.7% and 8.5%, respectively (p > 0.05). There was no increased risk of SGA (unadjusted OR = 1.28, 95% confidence interval [CI] 0.9-1.83; adjusted OR = 1.35, 95% CI 0.91-2.01). The IUGR rate was 2.7% in pregnant women with PS deficiency versus 4.1% in the control group (p > 0.05). Also, we did not find a significant risk of IUGR (OR = 0.66; 95% CI 0.34-1.28; adjusted OR = 0.843; 95% CI 0.42-1.70).

CONCLUSIONS

In women with PS deficiency treated with LMWH, the risk of SGA and IUGR is similar to the one found in healthy pregnant women.

Surgical management of iliofemoral vein thrombosis during pregnancy and the puerperium

BACKGROUND

The risk of deep venous thrombosis is elevated during pregnancy and the puerperium. Therapy is usually limited to conservative measures as invasive thrombus removal is feared because of possible complications. However, leg- or life-threatening situations require fast thrombus removal, and the long-term rate of post-thrombotic syndrome (PTS) may be reduced by venous recanalization. Our center's experience may give support to surgical venous thrombectomy (VT).

METHODS

Between 1996 and 2016, all women who received VT for pregnancy-related deep venous thrombosis in our department were included. Retrospective data were combined with a current follow-up.

RESULTS

The study included 82 women with a mean age of 29 years (17-38 years). An additional arteriovenous fistula was performed in 79 and planned simultaneous cesarean section in 13 patients. Neither pulmonary emboli nor fetal complications occurred during surgery, and perioperative and postoperative mortality was 0%. Operative revision was required in 38% mainly for rethrombosis (24%) and bleeding (12%). One fetus died 2 months after VT of unrelated causes. After a mean of 83 months, complete venous recanalization was seen in 88%, venous valve sufficiency in 90%, and PTS in 31% without any ulcers. At 10 years, PTS incidence rose to reach 50% with limited statistical significance because of the number of patients reaching long-term follow-up.

CONCLUSIONS

Iliofemoral venous recanalization during pregnancy can be performed safely in a specialized center, with lower PTS rates than in historical controls.

Hereditary risk factors for thrombophilia and probability of venous thromboembolism during pregnancy and the puerperium

Venous thromboembolism (VTE) is a leading cause of maternal mortality. Few studies have evaluated the individual risk of gestational VTE associated with heritable thrombophilia, and current recommendations for antenatal thromboprophylaxis in women with severe thrombophilia such as homozygous factor V Leiden mutation (FVL) depend on a positive family history of VTE. To better stratify thromboprophylaxis in pregnancy, we aimed to estimate the individual probability (absolute risk) of gestational VTE associated with thrombophilia and to see whether these risk factors are independent of a family history of VTE in first-degree relatives. We studied 243 women with the first VTE during pregnancy and the puerperium and 243 age-matched normal women. Baseline incidence of VTE of 1:483 pregnancies in women ≥35 years and 1:741 deliveries in women <35 years was assumed, according to a recent population-based study. In women ≥35 years (<35 years), the individual probability of gestational VTE was as follows: 0.7% (0.5%) for heterozygous FVL; 3.4% (2.2%) for homozygous FVL; 0.6% (0.4%) for heterozygous prothrombin G20210A; 8.2% (5.5%) for compound heterozygotes for FVL and prothrombin G20210A; 9.0% (6.1%) for antithrombin deficiency; 1.1% (0.7%) for protein C deficiency; and 1.0% (0.7%) for protein S deficiency. These results were independent of a positive family history of VTE. We provide evidence that unselected women with these thrombophilias have an increased risk of gestational VTE independent of a positive family history of VTE. In contrast to current guidelines, these data suggest that women with high-risk thrombophilia should be considered for antenatal thromboprophylaxis regardless of family history of VTE.

Recurrent pregnancy loss: what is the impact of consecutive versus non-consecutive losses?

STUDY QUESTION

Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic impact in women with secondary RPL.

WHAT IS KNOWN ALREADY

The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy losses plays a role for the prognosis in patients with a prior birth.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study of pregnancy outcome in patients with unexplained secondary RPL included in three previously published, Danish double-blinded placebo-controlled trials of intravenous immunoglobulin (IvIg) conducted from 1991 to 2014. No other treatments were given. Patients with documented explained pregnancy losses (ectopic pregnancies and aneuploid miscarriages) were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the 168 patients included in the trials, 127 had secondary RPL and experienced a subsequent live birth or unexplained pregnancy loss in the first pregnancy after giving informed consent to participate in the trials (the index pregnancy). Data analyzed by multivariate analysis included the independent variables age, the number of early pregnancy losses before and after the last birth, respectively and a second trimester pregnancy loss before or after the last birth, respectively. The outcome variable was unexplained loss in the index pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

In patients with secondary RPL, both a late and each early loss before the last birth did not significantly influence the risk of a new pregnancy loss in the index pregnancy: incidence rate ratio (IRR) 1.31 (95% CI 0.62-2.77) and IRR 0.88 (95% CI 0.70-1.11), respectively. In contrast, the impact on risk of pregnancy loss conferred by a late and by each early pregnancy loss occurring after the birth was significant: IRR 2.15 (95% CI 1.57-2.94, P < 0.0001) and IRR 1.14 (95% CI 1.04-1.24, P = 0.002), respectively.

LIMITATIONS, REASONS FOR CAUTION

Of the patients, 48% were treated with IvIg, which could influence the results. However, allocation to IvIg was random and prognostic variables were equally distributed in IvIg and placebo-treated patients.

WIDER IMPLICATIONS OF THE FINDINGS

A birth in women with secondary RPL eradicates the negative prognostic impact of previous pregnancy losses and this finding is important for our understanding of the pathogenesis. It indicates that only consecutive pregnancy losses should count in the definition of RPL.

STUDY FUNDING/COMPETING INTERESTS

There was no particular funding for this study. The authors declare that there is no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable for two of the included randomized controlled trials. For the last trial: Clinical.Gov NCT00722475.

The Impact of Inherited Thrombophilia Types and Low Molecular Weight Heparin Treatment on Pregnancy Complications in Women with Previous Adverse Outcome

PURPOSE

To assess the distribution of births and spontaneous abortions, first-trimester abortion (FTA) and mid-trimester abortion (MTA), in untreated (n=128) and low molecular weight heparin (LMWH) treated pregnancies (n=50) of the same women with inherited thrombophilias and adverse pregnancy outcome (APO) in previous pregnancies. We particularly investigated the impact of LMWH on reducing the pregnancy complications in two thrombophilia types, "Conventional" and "Novel".

MATERIALS AND METHODS

50 women with inherited thrombophilia (26 Conventional and 24 Novel) and APO in previous pregnancies were included in the study. Conventional group included factor V Leiden (FVL), prothrombin G20210A (PT) mutations and antithrombin (AT), protein S (PS), and protein C (PC) deficiency, while the Novel group included methylentetrahydrofolate-reductase (MTHFR), plasminogen activator inhibitor-1 (PAI-1), and angiotensin converting enzyme (ACE) polymorphism. APO was defined as one of the following: preterm birth (PTB), fetal growth restriction (FGR), preeclampsia (PE), intrauterine fetal death (IUFD), placental abruption (PA) and deep venous thrombosis (DVT).

RESULTS

There was no difference in distribution of births and spontaneous abortions between Conventional and Novel thrombophilia in untreated pregnancies (χ²=2.7; p=0.100) and LMWH treated pregnancies (χ²=0.442; p=0.506). In untreaed pregnancies thrombophilia type did not have any impact on the frequency of FTA and MTA (χ²=0.14; p=0.711). In birth-ended pregnancies LMWH treatement reduced the incidence of IUFD (p=0.011) in Conventional and FGR, IUFD, and PTB in Novel thrombophilia group.

CONCLUSION

The equal impact of two thrombophilia types on the pregnancy outcomes and a more favorable effect of LMWH therapy on pregnancy complications in Novel thrombophilia group point the need for Novel thrombophilias screening and the future studies on this issue should be recommended.

Antibodies directed against annexin A2 and obstetric morbidity

Acquired and inherited thrombophilia have both been reported to be associated with an increased risk of obstetric complications in early or later stages of pregnancy. Annexin A2 (ANXA2) is strongly expressed in vascular and placental tissues and plays a crucial role in fibrinolysis. The aim of the present study was to evaluate the prevalence of antibodies directed against ANXA2 in patients with recurrent miscarriage or obstetric complications. Anti-ANXA2 antibodies (aANXA2) were detected by ELISA in the sera from 46 women with obstetric morbidity, mainly recurrent miscarriage. The cut-off value for positivity was defined as 3 standard deviations above the mean optical density (OD) obtained in the sera from 42 female blood donors. The prevalence of aANXA2 in patients and healthy individuals was 15.2% and 2.3%, respectively. A statistically significant difference was observed between the 2 groups in terms of aANXA2 IgG titers (p=0.01). The highest aANXA2 levels were observed in sera from 2 patients with recurrent miscarriage and one patient with preeclampsia. aANXA2 could play a role in thrombotic mechanisms leading to recurrent pregnancy loss and placental vascular disease. Further studies are needed to determine whether ANXA2 is critical for maintenance of placental integrity.