Frequency of antiphospholipid antibodies and factor V (G1691A), prothrombin (G20210A) gene polimorphism among women with pregnancy complications

Thrombophilia these days is a subject of many medical research including obstetric and gynecology where causing feto-maternal complications. In women predispose to venous thromboembolism in high risk situation like pregnancy, puerperium, operation, prolonged bed rest or hormonal treatment. For fetal complication account miscarriages, intrauterine deaths, IUGR, and for maternal account premature placental separation and severe preeclampsia. Diagnostic panel include inherited factors like factor V Leiden and prothrombin mutation, activated protein C resistance and acquired like anticardiolipin antibodies, antibodies against beta2-glicoprotein 1 and lupus anticoagulant. The aim of this paper is estimation ofthrombophilia as a causative factor of pregnancy complications and attempt to establish screening criteria for thrombophilia. Material involved 36 women with pregnancy complications divided into three groups correlating with trimester when pregnancy loss occured. All patients had genetic, hormonal and anatomic tests done on purpose to exclude other possible causes of miscarriages. All women had done both types of tests for inherited and acquired thrombophilia. For factor V and II gene polimorphism we used PCR and RLFP method. Acquired protein C resistance and lupus anticoagulant was tested using chronometric method with the use of time measurement of optical density accompanying coagulation. Anticardiolipin antibodies and antibodies against beta2-glicoprotien 1 were measured in ELISA tests. Our current results present the frequency of at least one thrombophilic factor in 16.6% patients. The highest frequency rate was observed among women with pregnancy loss between 7th and 12th gestational week--19.04%. In this group we also noticed the highest number of miscarriages. In remaining two groups, with pregnancy loss between 12th and 22nd and after 22nd gestational week, one case of thrombophilia occurred in each group.     

Perinatal aspects of inherited thrombophilia

The identified main causes of inherited thrombophilia are deficiencies of antithrombin, protein C and protein S, activated protein C (APC) resistance and the factor V Leiden mutation, mutant factor II, and inherited hyperhomocysteinemia. In women from symptomatic families these defects may be associated with an increased risk of venous thrombosis in pregnancy and recurrent fetal loss. Inherited thrombophilia is common and appears to be a multigene disorder. The thrombotic risk would seem to be greatest in women with antithrombin deficiency and more than one thrombophilia defect. The abnormalities that are now recognized represent only part of the genetic predisposition to thrombosis. In assessing thrombotic risk in pregnancy, acquired risk factors as well as genetic predisposition should be considered. Increasing age, obesity, immobility, and delivery by cesarean section are major risk factors. Pregnancy should be planned, and each patient should be managed on an individual basis. In pregnancy, heparin is the anticoagulant of choice, and as far as possible, treatment with warfarin should be avoided because of the risks to the fetus. When patients are on long-term treatment with warfarin, pregnancy should be avoided, and warfarin should be discontinued prior to embarking on a pregnancy or as soon as pregnancy is suspected and before 6 weeks' gestation. In women from symptomatic families with antithrombin deficiency, adjusted dose heparin throughout pregnancy is recommended and warfarin for at least 3 months post partum. In protein C and protein S deficiency, factor V Leiden, or mutant factor II, treatment can be based on personal and family history. Thromboprophylaxis in late pregnancy and post partum should be considered. Fetal loss may be increased in women with inherited thrombophilia. The risk appears greatest in women with antithrombin deficiency and women with more than one thrombophilia defect. A number of reports have claimed that prophylactic treatment with heparin during pregnancy has resulted in successful pregnancy in women with recurrent fetal death and inherited thrombophilia.     

Factor V Leiden in women: a thrombotic risk factor or an evolutionary advantage?

Factor V Leiden is a common gain-of-function gene mutation resulting in a genetic predisposition to thromboembolic complications. Growing evidence in the literature indicates an interaction between factor V Leiden thrombophilia and acquired prothrombotic conditions such as contraceptive use or hormone replacement therapy, resulting in an increased risk of venous thromboembolism (VTE). Similarly, when combined with the prothrombotic influence of pregnancy, women who are carriers of factor V Leiden are faced with an increased risk of adverse pregnancy outcomes, including VTE, pre-eclampsia, fetal loss, placental abruption, and fetal growth restriction. The results of the most important meta-analyses on the relationship between inherited (factor V Leiden) and acquired thrombophilia in women are analyzed in this review, along with the possible evolutionary role of this mutation.     

The association of inherited thrombophilia and intrauterine fetal death: a case-control study

Inherited thrombophilias are probably associated with placenta-mediated pregnancy complications, but the strength of the association between inherited thrombophilias and intrauterine fetal death after 22 gestational weeks varies due to small sample size and different methodologies used across studies. The objective of the present study was to investigate the association of inherited thrombophilia and intrauterine fetal death in a case-control design. We studied 105 women with a history of intrauterine fetal death after 22 gestational weeks and 262 controls with live births. We investigated the prevalence of the factor V Leiden (F5 rs6025) and prothrombin gene G20210A (F2 rs1799963) polymorphisms, and antithrombin, protein C and protein S deficiencies, and their association with intrauterine fetal death. Results were presented as percentages and odds ratios (ORs) with 95% confidence intervals (CIs). A total of 18.4% of cases and 11.8% of controls were positive for at least one inherited thrombophilia (OR 1.7; 95% CI 0.9-3.1). The prothrombin gene G20210A polymorphism (OR 4.0; 95% CI 1.1-14.4), but not the factor V Leiden polymorphism, or antithrombin, protein C or protein S deficiencies, was associated with intrauterine fetal death after 22 weeks of gestation. Compared with women with live births only, women with a history of intrauterine fetal death after 22 gestational weeks were significantly more often carriers of the prothrombin gene G20210A polymorphism.     

Inherited thrombophilia, pregnancy, and oral contraceptive use: clinical implications

Inherited thrombophilia has been reported to be associated with an increased risk for complications of pregnancy, including venous thromboembolism (VTE) as well as preeclampsia (PEC), fetal loss (FL), fetal growth retardation (FGR), and abruptio placentae (AP), the latter probably due to inadequate placental perfusion. The estimate of risk largely depends on the kind of thrombophilia and on the criteria applied for the selection of the patients, producing in some cases contradictory results. Convincing evidence is available that deficiency of antithrombin III (AT), protein C (PC), and protein S (PS) is a risk factor for VTE and late FL. Factor V (Leiden) is associated with an increased risk for VTE, unexplained recurrent FL, late FL, and perhaps PEC; prothrombin G20210A is a weak risk factor for VTE. So far, the data available for FGR and AP are scarce. However, the absolute risk for VTE during pregnancy and puerperium is between 1 and 3%, in comparison with the baseline risk of 0.08%. Antithrombotic prophylaxis with subcutaneous heparin is warranted during puerperium in all women with thrombophilia and throughout all pregnancy in women at higher risk (AT deficiency, homozygosity for factor VLeiden, and perhaps PC and PS deficiencies); treatment with subcutaneous heparin for prevention of FL among women with thombophilia is under investigation. Presence of inherited thrombophilia increases the risk for VTE due to oral contraceptives up to an absolute risk of 3 per 1000 person-years, in comparison with the baseline risk of 3 to 6 per 10000 person-years; the risk is further increased by first usage, the use of preparations containing third-generation progestins, and thrombophilia due to AT, PC, and PS deficiency as well as homozygous factor V (Leiden) and combined defects.     

Thrombophilia and pregnancy

The risk of venous thromboembolism (VTE) increases up to 5-10-fold during pregnancy and VTE represents the first cause of maternal mortality. The annual incidence of VTE is 0.97 per 1000 women during pregnancy and 7.19 per 1000 in the puerperium. The risk is higher in carriers of inherited thrombophilia. Prophylaxis of VTE during pregnancy in thrombophilic women, is still controversial, whereas there is agreement on the used of LMWH or oral anticoagulants during puerperium. LMWH is suggested during pregnancy in antithrombin deficient women, compound heterozygotes for prothrombin G20210A and factor V Leiden, and homozygotes for these conditions, with no prior VTE. In heterozygotes for F V Leiden or prothrombin G20210A with no prior VTE surveillance is preferred during pregnancy and LMWH or OA during puerperium. For patients with APLAs and no prior VTE or fetal loss, one of the following approaches is suggested: prophylactic LMWH and/or low-dose aspirin, mini dose heparin, surveillance (7 degrees ACCP). Patients with APLAs and a history of thrombosis should receive therapeutic-dose LMWH or UH plus low-dose aspirin during pregnancy and long term OA postpartum. In women with prior VTE and inherited thrombophilia, prophylactic or intermediate-dose LMWH is recommended during pregnancy plus post-partum OA. Intermediate-dose LMWH during pregnancy is suggested in antithrombin-deficient women, compound heterozygotes for prothrombin G20210A and factor V Leiden, and homozygotes for these conditions.     

The investigation and management of inherited thrombophilia

Inherited thrombophilia can be defined as a genetically determined tendency to venous thromboembolism. Genetic risk factors for venous thrombosis include antithrombin deficiency, protein C deficiency, protein S deficiency, activated protein C resistance due to the factor V gene Leiden mutation, inherited hyperhomocysteinaemia, elevated factor VIII levels and the prothrombin gene G20210 A variant. A genetic risk factor is now identifiable in up to 50% of unselected patients with venous thrombosis. Individuals with inherited thrombophilia may develop venous thrombosis at a young age, or they may present with thrombosis at an unusual site or in the apparent absence of any precipitating event. A family history of thrombosis is suggestive of inherited thrombophilia. Laboratory investigations for inherited thrombophilia should include testing for activated protein C resistance and the factor V gene Leiden mutation, and screening for deficiencies of antithrombin, protein C or protein S. Screening for the prothrombin gene G20210 A variant, and measurement of plasma factor VIII and homocysteine levels should be considered in individual cases. In recent years the multifactorial nature of thrombophilia, both circumstantially and on a genetic level, has become increasingly apparent. Individuals with more than one inherited thrombophilia risk factor are particularly prone to thrombosis and their identification is a priority.     

Thrombophilia and fetal loss

A large body of evidence obtained during the last 6 years suggests a significant role for inherited thrombophilia in the development of gestational vascular complications. Case-control studies demonstrated that thrombophilia is more prevalent in cohorts of women with pregnancy loss. Other complications such as preeclampsia, placental abruption, and intrauterine growth retardation may also be associated with thrombophilia. Placental pathologic findings in women with thrombophilia are hallmarked by thrombosis and fibrin deposition. Preliminary case-control studies suggest that low-molecular-weight heparins are effective in preventing pregnancy loss in women with thrombophilia and previous fetal wastage.     

Risk factors of thromboembolism associated with pregnancy and the puerperium. Role of inherited and acquired thrombophilia

Thromboembolism in pregnancy and the puerperium and inherited or acquired thrombophilia are associated. Thrombophilia can be revealed by pregnancy. Thrombotic risk during pregnancy and the puerperium is higher in asymptomatic women with than without thrombophilia. Antithrombin deficiency, combined deficiencies and homozygous or double-heterozygotes factor V Leiden and factor II G 20210 A mutations are associated with a higher thrombotic risk than heterozygote mutations or protein S and C deficiencies, whereas hyperhomocysteinemia does not appear as a risk factor for maternal thromboembolic disease. Antiphospholipid syndrome with lupus anticoagulant is strongly associated with thrombotic risk in pregnancy and the puerperium. Further studies are required to assess the thrombotic risk in women with preeclampsia as well as early or late recurrent pregnancy loss.     

Inherited thrombophilia and gestational vascular complications

The most common causes of inherited thrombophilia, the factor V Leiden and the factor II A20210 mutations, confer a higher risk of venous thromboembolism. Moreover, several studies have suggested that they can have a role in the occurrence of gestational vascular complications in otherwise unexplained recurrent fetal losses, hypertensive disorders of pregnancy and fetal growth restriction. Observational and case-control studies addressing these issues are available in literature. However, longitudinal, perspective studies are lacking. Mild hyperhomocysteinaemia can be due partly to inherited susceptibility--as the homozygous carriership of the T677 variant in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR). Case-control studies have been carried out on a possible association between unexplained fetal losses and mild hyperhomocysteinaemia. Although case-control and perspective studies are available on hyperhomocysteinaemia and other gestational vascular complications the data are conflicting.Intervention studies have been carried out to prevent adverse obstetric outcomes in women with factor V Leiden or factor II A20210 mutations and previous adverse outcomes. Although these are not randomized controlled trials, all have found significantly better outcomes in treated pregnancies compared to those of untreated pregnancies in the same women.     

Management options for thrombophilias

Thrombophilias may be inherited or acquired, continuing or transient, and may contribute strongly or weakly to thrombosis. They may predispose to venous thromboembolism alone or also to artery occlusion. Advice on management must recognize these variations. The presence of an inherited thrombophilia should not alter the intensity of anticoagulant therapy, given that antithrombin, protein C, or protein S deficiency, factor V Leiden, and the prothrombin G20210A mutation are not unusually anticoagulant resistant. However, they can increase the optimal treatment duration after a first thromboembolic event. Optimal duration depends on the balance between thrombosis risk off treatment and bleeding risk during extended anticoagulant therapy, and needs to be separately estimated for each individual with thrombosis and thrombophilia. The higher the thrombosis risk and the lower the bleeding risk, the longer the optimal treatment duration. This balance favors continued (but perhaps not indefinite) therapy in antithrombin, protein C, and protein S deficiency, and perhaps also in patients with the factor V Leiden or prothrombin mutations if their bleeding risk is low. Thrombosis that complicates active malignancy, the antiphospholipid syndrome, or heparin-induced thrombocytopenia needs special consideration: recent clinical trials suggest that low molecular weight heparins are more effective than warfarin in thrombosis with cancer, and that a more intense warfarin effect is not needed for patients with antiphospholipid syndrome and thrombosis. Debate continues about the place of screening for presymptomatic but affected relatives of patients with thrombosis and an inherited predisposition. It is essential that any family testing be done only with the informed consent of all concerned. Given consent, there is general support for family testing in antithrombin, protein C, or protein S deficiency and where the factor V Leiden or prothrombin mutation is strongly penetrant and expressed. There is, however, a strong argument that any testing in families in which clotting factor polymorphisms are weakly expressed should be restricted to young women when they consider hormonal contraception or pregnancy, given that these acquired factors multiply the risk.     

The association between hereditary thrombophilias and pregnancy loss

The correlation between hereditary thrombophilia and fetal loss is supported by several observations. In murine models, the protein C system has been shown to be essential for the maintenance of pregnancy, as it indirectly acts as a growth factor for trophoblast cells and protects them from apoptosis. In humans, it has been shown that the placenta replaces the yolk sac as an essential source of blood supply to the embryo during the 8th and 9th weeks of gestation. Furthermore, meta-analysis of epidemiological data demonstrates a correlation between thrombophilic polymorphisms such as factor V Leiden and prothrombin 20210G-->A and isolated or recurrent fetal losses. Finally, therapeutic non-controlled trials indicate the benefits and safety of low-molecular weight heparins as secondary prophylaxis. However, it is still necessary to further clarify the association between thrombophilia and fetal loss, especially during a first pregnancy, with regard to the type of pregnancy loss and with respect to other related factors.     

Genetic factors in fetal growth restriction and miscarriage

Recently, several investigations concerning disadvantageous genetic factors in human reproduction have progressed. Inherited thrombophilia, such as factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase mutations; gene polymorphisms of detoxification enzyme (CYP1A1); growth factors (insulin-like growth factor-I); and hormones such as angiotensinogen and CYP17 are involved in the pathogenesis of fetal growth restriction. The inherited thrombophilia, gene polymorphisms of coagulation and anticoagulation factor such as thrombomodulin, endothelial protein C receptor, plasminogen activator inhibitor 1, and factor XIII; human lymphocyte antigen (HLA-G); detoxification enzymes (glutathione- S-transferase M1); cytokines such as interleukin (IL) -1 and IL-6; hormones (CYP17); vasodilators (nitric oxide synthase 3); and vitamins (transcobalamin) are involved in the pathogenesis of sporadic and recurrent miscarriage. It is likely that a gene polymorphism or mutation susceptible to reproductive failure has a beneficial effect on the process of human reproduction with or without the environmental interaction. The factor V Leiden mutation has genetic advantages that are believed to be an improved implantation rate in in vitro fertilization and a reduction of maternal intrapartum blood loss. It has also been demonstrated that the CYP17 A2 allele has bidirectional effects on human reproduction, including increases in susceptibility to recurrent miscarriage and fetal growth enhancement.     

Coagulation factor deficiency as a cause of recurrent fetal loss: a red herring!

Whether severe coagulation factor deficiency can cause adverse pregnancy outcomes or recurrent fetal loss is not definitely known. We report here on five women with severe deficiency of coagulation factors (two factor X, one factor XI, one factor VII and one von Willebrand factor) who presented with history of unexplained fetal loss or with adverse pregnancy outcome. Detailed investigations of thrombophilia showed that four patients were positive for antiphospholipid antibodies, one of whom was also homozygous for the plasminogen-activator inhibitor-1 4G/4G polymorphism, and the fifth patient was deficient for protein C. Despite the concomitant presence of both coagulation factor defect and thrombophilia, fetal loss may be attributed to factor defect that in reality is a red herring, with underlying thrombophilia not being evaluated.     

Inherited thrombophilia and pregnancy loss

A growing body of evidence obtained during the past 6 years suggests a significant role for inherited thrombophilia in the development of gestational vascular complications. Case-control and cross-sectional studies have demonstrated that thrombophilia is more prevalent in cohorts of women with pregnancy loss.Placental pathological findings in women with thrombophilia are hallmarked by thrombosis and fibrin deposition. Preliminary case-control studies suggest that low-molecular-weight heparins (LMWH) are effective in preventing pregnancy loss in women with thrombophilia and previous fetal wastage.     

Usefulness of screening for congenital or acquired hemostatic abnormalities in women with previous complicated pregnancies

Activated protein C resistance (APCR) is a common cause of familial thrombophilia and venous thrombosis. The aim of the study was to investigate the prevalence of APCR associated with factor V Leiden mutation and its relevance in comparison to other risk factors for thromboembolic disorders in women with a history of previous complicated pregnancies (history of fetal loss in the second and third trimester n = 34, preeclampsia n = 46). The frequency of APCR was significantly higher in women with a history of fetal loss and preeclampsia (23.5 and 26.1%, respectively) compared with a control group (3.8%). The prevalence of antithrombin, protein C and protein S deficiencies and the presence of antiphospholipid antibodies were also investigated: the prevalence of at least one disorder was 41.2% in the group with previous fetal loss, 37.0% in the group with previous preeclampsia and 7.5% in the control group.     

Thrombophilic dimension of recurrent fetal loss in Indian patients

We studied the prevalence of acquired and genetic thrombophilia in 198 women with recurrent fetal loss who were having three or more than three abortions. Seventy-nine women had only early pregnancy losses, that is, first trimester abortions, 30 women had only late pregnancy losses, that is, second and third trimester abortions whereas 89 had both early and late pregnancy losses. The control group included 100 age-matched fertile parous women who did not have any obstetric complications and had at least one normal healthy child. Several genetic and acquired thrombophilia markers were studied. The strongest association was observed with anticardiolipin (odds ratio 22.6, confidence interval 5.7-89, P = 0) followed by lupus anticoagulant, anti-beta2 glycoprotein-1, antiannexin. Association of antiphospholipid antibody syndromes was detected with the time of pregnancy loss in anticardiolipin, lupus anticoagulants, which was significantly associated with early pregnancy loss as compared with second and third trimester loss. In case of beta2 glycoprotein-1, antiannexin it was less significantly associated with early pregnancy loss as compared with second and third trimester loss. The risk of fetal loss with protein S deficiency was the highest risk observed for any heritable thrombophilia, followed by protein C, factor V Leiden, endothelial protein C receptor, antithrombin III deficiency and beta448 fibrinogen polymorphism. Modest risks were also observed with 5,10-methylenetetrahydrofolate reductase, plasminogen activator inhibitor 4G/4G polymorphisms and beta448 fibrinogen polymorphism. A combination of two or more than two genetic risk factors were observed in 55 (27.7%), whereas the genetic and acquired risk factors were observed in 107 (54%) of the cases. Thrombophilia is an important contributing factor for both early and late pregnancy losses; approximately two-thirds of our cases of unexplained fetal losses could be explained by acquired or heritable thrombophilia or both, which is in line with other western studies.     

Evaluation of a tissue factor dependent factor V assay to detect factor V Leiden: demonstration of high sensitivity and specificity for a generally applicable assay for activated protein C resistance

Resistance to the anticoagulant effects of activated protein C (APC) is now considered the most prevalent cause of inherited thrombophilia. The great majority of patients with activated protein C resistance (APCR) have a missense mutation in the factor V molecule (factor V Leiden, FVR506Q) resulting in defective inactivation of factor Va due to a loss of an APC cleavage site. The diagnosis of APCR has been based upon the inability of APC to prolong the activated partial thromboplastin (aPTT) clotting time in subjects with APCR. However, this assay has a number of deficiencies which limit its general use. We have evaluated a newly described one-stage tissue factor dependent factor V coagulation assay for APCR in 117 patients and controls and compared the results of this assay in a blinded manner to a polymerase chain reaction (PCR) based assay for the molecular defect of factor V Leiden. 43% (50 /117) of the patients studied were receiving coumadin or heparin, or had a lupus anticoagulant. The tissue factor dependent factor V assay had 100% specificity and sensitivity for factor V Leiden and successfully predicted a homozygous state in the three documented homozygotes. The PCR-based assay for factor V Leiden resulted in a single false positive assay due to a silent A to C transition at nucleotide 1692 resulting in the loss of the Mnl restriction endonuclease cleavage site. The single-stage tissue factor dependent factor V assay is a highly sensitive and generally applicable assay for APCR.     

Evidence-based indications for thrombophilia screening

Thrombophilic defects have been shown to be associated with an increased risk of venous thrombosis, fetal loss, and gestational complications. The knowledge about the clinical relevance of thrombophilic defects is increasing, and evidence-based indications for thrombophilia screening are therefore discussed in this review. Selective thrombophilia screening based on previous personal and/or family history of venous thromboembolism is more cost-effective than universal screening in all patient groups evaluated. In the majority of patients with acute venous thrombosis, the results of thrombophilia screening do not influence the duration of oral anticoagulation. The only patient population who clearly profits from thrombophilia screening in this situation are patients with a newly diagnosed antiphospholipid syndrome, because prolonged anticoagulation can avoid the high incidence of recurrence in this patient population. Because of the increased risk of venous thrombosis during pregnancy and the puerperium, thrombophilia screening is indicated in selected patients with a previous history of venous thrombosis or a positive family history. Significant associations with early and late pregnancy loss are observed for carriers of the heterozygous factor V Leiden mutation, the heterozygous prothrombin-mutation G20210A and anticardiolipin antibodies, while protein S deficiency is significantly associated with late pregnancy loss. Antithrombotic drugs like UFH, LMWH or low-dose aspirin may have a potential therapeutic benefit in patients with recurrent pregnancy loss and thrombophilia, but placebo-controlled, multicenter trials are urgently needed to clarify this issue. Although a supra-additive effect for the risk of venous thrombosis is observed between oral contraceptives and some thrombophilias, the absolute incidence of venous thromboembolism is low in premenopausal women and mass screening strategies are therefore unlikely to be effective. While antiphospholipid antibodies are known to be associated with arterial thrombosis, screening for heritable thrombophilias is not useful in arterial thrombosis, although subgroup analysis indicates that they may play a role particularly in young patients and children.     

Screening for inherited thrombophilia: indications and therapeutic implications

BACKGROUND AND OBJECTIVES: In recent years knowledge concerning inherited and acquired causes of thrombophilia has increased greatly. The most common inherited traits (deficiency in antithrombin, protein C, or protein S, factor V Leiden, prothrombin G20210A) and mild hyperhomocysteinemia are diagnosed in at least 40% of patients with venous thromboembolism (VTE). INFORMATION SOURCES: The authors work in this field, contributing to multicenter clinical and laboratory investigations and to peer-reviewed journals with original papers. The material examined in this review includes articles published in journals covered by MedLine. STATE OF THE ART: The associated risk for VTE is different according to genotype, being higher among the carriers of natural anticoagulant deficiencies and homozygotes for factor V Leiden. The overall prevalence of thrombophilic traits in the general population being near to 10% renders the probability of carrying multiple defects not excessively rare, with a further increase in thrombotic risk of up to 20-fold. Thus, clinical penetrance is heterogeneous, producing either mild or severe venous thrombotic manifestations, which can be unprovoked or associated with circumstantial risk factors and occur in either young or advanced age. More recently, inherited thrombophilia has been focused on as an important determinant of complications of pregnancy and puerperium. As expected, inherited thrombophilia produces an increased risk of VTE, particularly during puerperium. Moreover it is well established that thrombophilic women have an increased risk of late and/or recurrent fetal loss; whether they are at higher risk of pre-eclampsia, fetal growth restriction, and abruptio placentae is debated. Overall, 40% of women with obstetric complications other than VTE carry a thrombophilic trait. Yet, as a rule VTE and obstetric complications seem to occur in different individuals, probably because of the presence of unknown factors favoring one or other of these clinical manifestations. CONCLUSIONS AND PERSPECTIVES: Inherited thrombophilia is now viewed as a multicausal model, the clinical event being the result of gene-gene and gene-environment age-dependent interactions; the associated clinical manifestations can be heterogenous as regards severity as well as type of event (VTE or obstetric complication). Therefore the criteria for screening affected individuals who have suffered from the above complications or their relatives should not be very stringent. The patient's genotype could be a main determinant of the features of primary or secondary prophylaxis used in the affected individual.