Inherited thrombophilias and anticoagulation in pregnancy

Thromboprophylaxis, primary or secondary, should be considered in selected pregnant women with inherited thrombophilias; such women may be divided into high-, medium- and low-risk categories on the basis of the specific thrombophilic defect and any personal or family history of venous thromboembolism (VTE). Women at high risk of VTE should receive treatment doses of low-molecular-weight heparin (LMWH) throughout pregnancy and should remain on anticoagulation for 6 weeks postpartum, or, where appropriate, long-term. Women at moderate risk should be treated with prophylactic fixed-dose LMWH throughout pregnancy and for 6 weeks postpartum. Women at low risk should receive prophylactic fixed-dose LMWH for 6 weeks postpartum, and low-dose aspirin LDA should be considered during pregnancy. LWMH offers important advantages over unfractionated heparin (UFH); heparin-induced thrombocytopaenia (HIT) and osteopaenia are rarely seen. For treatment doses of LMWH, dosage adjustment based on anti-Xa levels is usually required as pregnancy progresses. Warfarin should be avoided throughout pregnancy. LMWH, UFH and warfarin are safe for breast-feeding mothers.     

Inherited thrombophilias and pre-eclampsia in Brazilian women

OBJECTIVE: The aim of the present study was to compare the distribution of G1691A, G20210A and C677T mutations in pre-eclamptic Brazilian women and in matched control women with an uncomplicated normal pregnancy. STUDY DESIGN: these mutations were investigated by PCR-RFLP in 83 normal pregnancies (control group) and in 30 pre-eclamptic pregnant women (severe form). RESULTS: G1691A mutation was detected neither in the control group nor in pre-eclamsia women. G20210A mutation was detected in heterozygosis in 3 (3.61%) control subjects, but not in pre-eclampsia group. C677T mutation was detected in homozygosis in 6 (7.23%) control subjects and 2 (6.67%) pre-eclamptic women and in heterozygosis in 31 (37.3%) control subjects and 12 (40%) pre-eclamptic women. Differences in the mutation frequencies detected in the two groups were not statistically significant. CONCLUSION: No correlation was observed between pre-eclampsia and presence of G1691A, G20210A and C677T mutations in Brazilian women.     

Inherited thrombophilias and adverse pregnancy outcome: screening and management

Inherited thrombophilias are a heterogenous group of conditions which have been implicated in a variety of pregnancy complications. Evidence is mounting that implicates these inherited disorders in a range of pregnancy outcomes, including recurrent miscarriage, late fetal loss, preeclampsia, abruptio placentae, and intrauterine growth restriction. The most commonly identified inherited thrombophilias consist of Factor V Leiden and the prothrombin gene mutation G20210A. Rarer inherited thrombophilic conditions include deficiencies of protein S, C and antithrombin. More recently, deficiency of protein Z has been linked to pregnancy complications, including preterm delivery. Clinical manifestations often are associated with the presence of more than one inherited thrombophilia, consistent with their multigenic nature. Some, but not all, studies investigating the use of heparin to prevent adverse pregnancy outcome have demonstrated a benefit. However, an adequate randomized trial is required to definitively determine whether heparin anticoagulation is the best prevention option in patients who harbor one or more inherited thrombophilias and are at risk for adverse pregnancy outcome. This review will summarize the association of thrombophilic conditions and obstetrical complications.     

Inherited thrombophilias in pregnant patients: detection and treatment paradigm

Inherited thrombophilias are the leading cause of maternal thromboembolism and are associated with an increased risk of certain adverse pregnancy outcomes including second- and third-trimester fetal loss, abruptions, severe intrauterine growth restriction, and early-onset, severe preeclampsia. Current information suggests that all patients with a history of prior venous thrombotic events and those with these characteristic adverse pregnancy events should be evaluated for thrombophilias. The most common, clinically significant, inherited thrombophilias are heterozygosity for the factor V Leiden and prothrombin G20210A mutations. The autosomal-dominant deficiencies of protein C and protein S are of comparable thrombogenic potential but are far less common. Homozygosity for the 4G/4G mutation in the type-1 plasminogen activator inhibitor gene and the thermolabile variant of the methylenetetrahydrofolate reductase gene, the leading cause of hyperhomocysteinemia, although relatively common, confer a low risk of thrombosis. In contrast, autosomal-dominant antithrombin deficiency and homozygosity or compound heterozygosity (ie, carriers of one copy of each mutant allele) for the factor V and prothrombin mutations are very rare but highly thrombogenic states. Regardless of their antecedent histories, pregnant patients with these highly thrombogenic conditions are at very high risk for both thromboembolism and characteristic adverse pregnancy outcomes, require full therapeutic heparin therapy throughout pregnancy, and need at least 6 weeks of postpartum oral anticoagulation. There is also compelling evidence that patients with the less thrombogenic thrombophilias and a history of venous thrombotic events or characteristic adverse pregnancy outcomes require prophylactic anticoagulant therapy during pregnancy and, in the case of prior thromboembolism, during the puerperium. Antepartum anticoagulation does not appear warranted among patients with less thrombogenic thrombophilias who are without a history of venous thromboembolism, characteristic adverse pregnancy outcomes, or other high risk factors for venous thrombosis.     

Inherited thrombophilias are not increased in "idiopathic" small-for-gestational-age pregnancies

OBJECTIVE: The purpose of this study was to determine (1). whether the inherited thrombophilias (the factor V Leiden and prothrombin gene mutations and the methylenetetrahydrofolate reductase [C677T] polymorphism) are increased in women with "idiopathic" (normotensive) small-for-gestational-age pregnancies and/or in their babies and (2). whether fetal carriage of a thrombophilia is associated with abnormal umbilical Doppler studies. STUDY DESIGN: This was a case-controlled study of normotensive women who were delivered of a singleton small-for-gestational-age baby (birth weight, <10th percentile adjusted for sex) with no clinical evidence of chromosomal or congenital abnormality. Control subjects were healthy women who were delivered of appropriate-for-gestational-age babies. RESULTS: One hundred forty-five women with small-for-gestational-age pregnancies and 290 control subjects were recruited. Small-for-gestational-age babies were born at an earlier gestational age (38 +/- 3.0 weeks) and with a lower birth weight (2373 +/- 521 g) than control babies (39.7 +/- 1.3 weeks and 3606 +/- 423 g, P <.01). There were no differences in the rates of factor V Leiden (2.8% vs 3.8%; relative risk, 0.79; 95% CI, 0.34-1.85), prothrombin gene mutation (2.8% vs 3.1%; relative risk, 0.92; 95% CI, 0.40-2.09), and methylenetetrahydrofolate reductase C677T polymorphism (13% vs 9%; relative risk, 1.27; 95% CI, 0.87-1.84) between mothers with small-for-gestational-age babies and control subjects, respectively. Inherited thrombophilias were not increased in small-for-gestational-age babies compared with control babies. Of small-for-gestational-age babies with abnormal umbilical artery Doppler studies (n = 25), 21% had a thrombophilia compared with 11% with normal umbilical artery Doppler studies (n = 68; relative risk, 1.75; 95% CI, 0.81-3.81). CONCLUSION: The rates of these inherited thrombophilias are not increased in normotensive women with small-for-gestational-age pregnancies. Further studies are required to determine whether thrombophilias are increased in small-for-gestational-age babies with abnormal umbilical Doppler study results.     

Acquired thrombophilias and pregnancy

Acquired thrombophilias are hypercoagulable states secondary to various aetiologies. In particular, during pregnancy the risks are exaggerated due to the underlying physiological changes. The commonest cause of acquired thrombophilia in pregnancy is antiphospholipid syndrome. Antiphospholipid syndrome (APS) is a complex multisystem disorder that has been associated with varied medical and obstetric complications. The pathogenesis of APS has been further elucidated in recent studies. The two most clinically significant antiphospholipid antibodies that are associated with recurrent pregnancy loss and thromboembolism are anticardiolipin antibodies (aCL) and lupus anticoagulant (LA). The laboratory diagnosis is based on the presence of moderate to high positive aCL and/or LA antibodies. It is crucial that APS is not inappropriately diagnosed as this has implications for counselling and management with thromboprophylaxis during pregnancy. Over the last decade there have been significant changes in the laboratory and clinical criteria for the diagnosis of APS. National and international collaborations have made efforts to standardize the laboratory methods. There have been very few randomized placebo-controlled trials of drug therapy and so not all drug treatment strategies have a strong evidence base. With current management strategies, using low-molecular-weight heparin and aspirin, a greater than 70% live birth rate may be achieved in affected pregnancies. A multidisciplinary approach in the management of these women is vital.     

Double versus single thrombophilias during pregnancy

Objective: The primary objective of this study was to evaluate whether women with double thrombophilias have a greater risk for obstetric complications as compared with women who have single thrombophilias.

Study design: This is a retrospective cohort study of all patients in a single practice with a clinically significant inherited thrombophilia and treated with anticoagulation between 2005 and 2013. Thrombophilias evaluated include: factor V Leiden, prothrombin G20210A gene mutation, protein S deficiency, protein C deficiency, and antithrombin III deficiency. Double thrombophilia was defined as the presence of two thrombophilias or homozygosity for factor V Leiden or prothrombin Gene Mutation. Demographic and obstetrical outcome data were collected. Data on all patients with double thrombophilias who met inclusion criteria was reported. Data was then compared between the patients with double thrombophilias and single thrombophilias with singleton gestations. The data was analyzed with Pearson’s chi-squared or Student’s t-test as appropriate with p value <.05 used for significance.

Results: Eighteen patients with clinically significant double thrombophilias who met inclusion criteria were identified. Most patients delivered full term (88.9%) and appropriate for gestational age (77.8%) infants. One hundred thirty-two patients with single thrombophilias and 14 patients with double thrombophilias with singleton gestations were then compared. Demographic characteristics were not significantly different between the two groups. There were no significant differences in obstetrical outcomes between patients.

Conclusions: There were no significant differences in obstetrical outcomes for patients with clinically significant double thrombophilias versus single thrombophilias when treated with anticoagulation.     

Single inherited thrombophilias and adverse pregnancy outcomes

INTRODUCTION: Inherited thrombophilia is believed to be a multiple gene disease with more than one defect. We aimed to determine the association between single thrombophilic patterns and a variety of pregnancy diseases. METHODS: 284 pregnant women were recruited for the present study and were divided in two groups: A group (176 controls) and B group (108 cases). Patients belonging to the B group had one of the following: severe pre-eclampsia, hemolysis, hepatic enzymes increase, hypertension and low platelet count (HELLP) syndrome, gestational hypertension, fetal growth restriction, intrauterine death, abruptio placentae and disseminated intravascular coagulopathy. To detect methylenetetrahydrofolate reductase (MTHFR) A1298C, MTHFR C677T, factor V Leiden, PAI-1, mutant prothrombin G20210A, an inverse hybridization technology was used. Plasma homocysteine, antithrombin (AT) III and protein S were determined. A modified functional activated protein C resistance was detected. RESULTS: MTHFR C677T and hyperhomocysteinemia were more prevalent than other thrombophilias. Deficiency in AT III was significantly linked with pre-eclampsia (relative risk 0.88; 95% CI 0.83-0.94). Activated protein C resistance (APCR) was significantly related to the abruptio placentae (relative risk 0.71; 95% CI 0.61-0.82). COMMENTS: Apart from the linkage between AT III deficiency and the occurrence of pre-eclampsia, and apart from the increased risk of abruptio placentae in pregnant women with altered APCR, we obtained findings in contrast with some of the published literature. In our case series, no association of pre-eclampsia with factor V Leiden or with prothrombin gene mutation was found.     

Genetic thrombophilias and preeclampsia: a meta-analysis

OBJECTIVE: To assess the relationship between the factor V Leiden (1691 G-A) single nucleotide polymorphism (SNP), the methylene tetrahydrofolate reductase (MTHFR) 677 C-T SNP, and the prothrombin 20210 G-A SNP and the risk of preeclampsia, by conducting a meta-analysis of all case-control studies with data on these polymorphisms and the risk of preeclampsia. DATA SOURCES: MEDLINE (1966 to November 2002), EMBASE (1980 to November 2002). Search terms included "preeclampsia," "thrombophilia," "factor V Leiden," "protein C," "MTHFR," "methylenetetrahydrofolate reductase," "homocysteine," and "prothrombin gene 20210."METHODS OF STUDY SELECTION: Case-control studies of genetic thrombophilias and preeclampsia were included. TABULATION, INTEGRATION, AND RESULTS: We identified 349 titles and reviewed 47 articles for inclusion and exclusion criteria. Thirty-one studies with 7,522 patients were included in the meta-analysis. Data from patients characterized as having severe preeclampsia were extracted and analyzed separately. The pooled odds ratio (OR) for the association of factor V Leiden and all cases of preeclampsia was 1.81 (95% confidence interval [CI] 1.14-2.87) and 2.24 (95% CI 1.28-3.94) for cases of severe preeclampsia. The pooled OR for the MTHFR 677 TT genotype and all preeclampsia was 1.01 (95% CI 0.79-1.29) and 1.38 (95% CI 0.93-2.06) for severe preeclampsia. The OR for the prothrombin 20210 polymorphism and all preeclampsia was 1.37 (95% CI 0.72-2.57) and 1.98 (.94-4.17) for severe preeclampsia. CONCLUSION: This meta-analysis suggests that the factor V Leiden SNP is associated with an increased risk of preeclampsia. Further studies are warranted to determine whether subgroups of high-risk women should be screened for this mutation.     

Frequency of selected thrombophilias in women with placental abruption

OBJECTIVE: There is a growing view that inherited or acquired thrombophilia may predispose a woman towards an adverse pregnancy outcome. The aim of this study was to investigate whether risk factors for placental abruption because of such thrombophilias (such as carriership of factor V Leiden (FVL), prothrombin G20210A gene mutation and homozygous MTHFR C677T) might be used as a predictor for placental abruption. METHODS: A retrospective case-control study conducted at the University Hospital, Palacky University, Olomouc, Czech Republic. One hundred and eighty women with placental abruption out of 20,175 deliveries (0.79%) were compared to 196 unselected gravidae. A detailed medical history was taken with special reference to factors related to hypercoagulation and blood was drawn for polymerase chain reaction analysis. The prevalence of FVL, prothrombin G20210A and MTHFR C677T was related to placental abruption. RESULTS: The heterozygous form of FVL was present in 20of 142 cases (14.1%) in the placental abruption group, compared to ten of 196 (5.1%) in the control group (odds ratio 3.0, 95% confidence interval 1.4-6.7). CONCLUSIONS: We found that factor V Leiden is a significant risk factor for placental abruption.     

The association between inherited thrombophilias and pregnancy-related hypertension recurrence

Purpose  

The aim of this study was to determine the association between inherited thrombophilias and pregnancy-related hypertension recurrence.     

The inherited thrombophilias: genetics,epidemiology, and laboratory evaluation

It is now possible to identify a predisposing thrombophilic condition for venous thrombosis in well over half of the cases. Certain thrombophilia diagnoses have a major impact on anticoagulant therapy, and hence it is incumbent upon physicians to understand how to diagnose and manage these conditions. This chapter covers the genetics and epidemiology of the inherited thrombophilias and provides a useful, common-sense approach to the laboratory evaluation of a patient with venous thrombosis.     

Practice bulletin no. 124: inherited thrombophilias in pregnancy

Inherited thrombophilias are associated with an increased risk of venous thromboembolism and also have been linked to adverse outcomes in pregnancy. However, there is limited evidence to guide screening for and management of these conditions in pregnancy. The purpose of this document is to review common thrombophilias and their association with maternal venous thromboembolism risk and adverse pregnancy outcomes, indications for screening to detect these conditions, and management options in pregnancy.     

Genetic thrombophilias and uterine artery Doppler velocimetry and preeclampsia.

OBJECTIVE: The aim of this study was to evaluate the correlation between genetic thrombophilic mutations, uterine artery Doppler at 24 weeks of gestation and preeclampsia. METHODS: In a case control study we performed the genetic analysis for Leiden mutation of factor V gene (FV), G20210A mutation of the prothrombin gene (PT) and C677T polymorphism of the methylenetetrahydrofolate reductase (MTHFR) gene in 103 women that had already attended routine ultrasonography scanner at 20 weeks at our Department. RESULTS: The frequency of heterozygous carriers of the factor V Leiden was 17.4% in the women with preeclampsia and abnormal artery Doppler compared with 3.12% in the patients with normal pregnancies. This difference was statistically significant (P<0.05). The frequency of mutation G20210A of prothrombin gene was 1.5 vs. 4.3% between women with normal pregnancies and with preeclampsia. This difference is not statistically significant. The frequency of homozygous patients for the C677T mutation of MTHFR gene among the patients with preeclampsia was 21.7% and in the control group was 10.3%, but this difference is not statistically significant. No thrombophilic gene variants were found in women with preeclampsia and normal uterine artery Doppler. CONCLUSION: We demonstrated the important association between factor V Leiden mutation, abnormal uterine Doppler at 24 weeks and preeclampsia in our population.     

Association between in vitro fertilization outcomes and inherited thrombophilias: a meta-analysis

Purpose

The aim of this study was to determine whether in vitro fertilization (IVF) outcomes are associated with inherited thrombophilias.

Methods

Several databases including PubMed, Embase, and Cochrane Library were retrieved up to 12 January 2016. The quality of the included studies was assessed by two authors. The associations of the following mutations in inherited thrombophilias and IVF outcomes were explored: factor V Leiden (FVL), prothrombin gene G20210A mutation (PGM), 5,10-methylentetrahydrofolate reductase (MTHFR) C677T, MTHFR (A1298C) and activated protein C resistance (APCR). The main outcome measures included CPR and implantation rate (IR). The relative risk (RR) and its 95 % confidence interval (CI) were calculated for effect index. Heterogeneity test was evaluated by Chi-square based on Q statistic and I ² statistics.

Results

A total of seven articles published between 2007 and 2015 with the ages of subjects between 30.9 and 36.2 were included. For subgroups analysis of CPR or IR, there were no significant differences in MTHFR (C377T), MTHFR (A1298C), FVL, PGM, and FVL/PGM mutation were found between the mutation group and control group (P?>?0. 05).

Conclusions

IVF outcomes are not associated with FVL, PGM, MTHFR (C677T), MTHFR (A1298C), and APCR mutation in inherited thrombophilias.