Factor V Leiden and G20210A prothrombin mutations in patients with recurrent pregnancy loss: data from the southeast of Turkey

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

OBJECTIVE

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

METHODS

DESIGN: Retrospective cohort study and systematic review of literature.

SETTING

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

PARTICIPANTS

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

RESULTS

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

CONCLUSION

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

PROSPERO REGISTRATION NUMBER

CRD42020223554.

Hereditary thrombophilia and recurrent pregnancy loss: a systematic review and meta-analysis

STUDY QUESTION

Is there an association between hereditary thrombophilia in pregnant women and risk of recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Pregnant women with hereditary thrombophilia have an increased risk of RPL, especially for pregnant women with the G1691A mutation of the factor V Leiden (FVL) gene, the G20210A mutation of the prothrombin gene (PGM), and deficiency of protein S (PS).

WHAT IS KNOWN ALREADY

Prior studies have suggested that pregnant women with hereditary thrombophilia have a higher risk of RPL, however, the results are inconsistent; furthermore, a complete overview is missing. This lack of information is an obstacle to the risk assessment of RPL in pregnant women with hereditary thrombophilia. A comprehensive meta-analysis on the relation between hereditary thrombophilia and the risk of RPL is needed.

STUDY DESIGN, SIZE, DURATION

A systematic review and meta-analysis was performed using observational studies published in English before 1 April 2020 to evaluate the relation between hereditary thrombophilia and risk of RPL.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Relevant studies were identified from PubMed, Web of Science, and EMBASE searches and complemented with perusal of bibliographies of retrieved articles. The exposure of interest was hereditary thrombophilia, including FVL mutation, PGM, deficiency of antithrombin (AT), deficiency of protein C (PC), and deficiency of PS. The overall risk estimates were pooled using random effects models. Subgroup and sensitivity analyses were carried out to explore possible sources of heterogeneity and assess the robustness of the results.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 89 studies involving 30 254 individuals were included. Results showed that women with FVL mutation (odds ratio (OR): 2.44, 95% CI: 1.96-3.03), PGM (OR: 2.08, 95% CI: 1.61-2.68), or deficiency of PS (OR: 3.45, 95% CI: 1.15-10.35) had higher risks of developing RPL. Compared with the reference group, there was no observed relation between a deficiency in AT or PC and RPL (all P > 0.05). Heterogeneity in the risk estimates of RPL was partially explained by geographic region, definitions of RPL, types of RPL, and controlled confounders. Sensitivity analyses validated the robustness of the findings.

LIMITATIONS, REASONS FOR CAUTION

Only 39 of the included studies controlled for one or more confounders, and the heterogeneity across all included studies was high. Based on the data available, we cannot determine whether this association is confounded by other potential risk factors of RPL.

WIDER IMPLICATIONS OF THE FINDINGS

This systematic review and meta-analysis show a possible association between hereditary thrombophilia and an increased risk of RPL, suggesting that testing for hereditary thrombophilia should be considered in individuals with RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Hunan Provincial Key Research and Development Program (Grant number: 2018SK2062) and National Natural Science Foundation Program (Grant number: 81973137). There are no conflicts of interest.

REGISTRATION NUMBER

N/A.

Factor V Leiden 1691G > A mutation and the risk of recurrent pregnancy loss (RPL): systematic review and meta-analysis

Background

Although numerous replication case-control studies have attempted to determine the association between Factor V Leiden (FVL) 1691G > A mutation and susceptibility to Recurrent pregnancy loss (RPL), there have been confliction among the results of various ethnic groups. To address this limitation, here we implemented first meta-analysis to provide with consistent conclusion of the association between FVL 1691G > A mutation and RPL risk.

Methods

After a systematic literature search, pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were used to evaluate the strength of the association. Additionally, meta-regression analyses were performed to find potential source of heterogeneity.

Results

In this meta-analysis, 62 studies, containing 10,410 cases and 9406 controls, were included in quantitative analysis. Overall population analysis revealed a significant positive association in the dominant (OR = 2.15, 95% CI = 1.84-2.50, P < 0.001), over-dominant (OR = 1.88, 95% CI = 1.61-2.19, P < 0.001), allelic (OR = 2.05, 95% CI = 1.79-2.35, P < 0.001), and heterozygote (OR = 1.97, 95% CI = 1.68-2.30, P < 0.001) models. Moreover, a significant association of dominant (OR = 3.04, 95% CI = 2.04-4.54, P < 0.001), over-dominant (OR = 2.65, 95% CI = 1.74-4.05, P < 0.001), and heterozygote (OR = 2.67, 95% CI = 1.81-4.22, P < 0.001) models was found in the Iranian population. The subgroup analysis indicated strong significant association in Asian, European, Africa population, and case-control studies but not in South Americans and cohort studies.

Conclusion

The FVL 1691G > A mutation and the risk of RPL confers a genetic contributing factor in increasing the risk of RPL, particularly in Iranians, except for South Americans.

Association between factor V Leiden mutation and recurrent pregnancy loss in the middle east countries: a Newcastle-Ottawa meta-analysis

PURPOSE

Heritable thrombophilia is a category of genetic disorders of the coagulation cascade with the increasing risk of thrombus formation and recurrent pregnancy loss (RPL). Factor V Leiden (FVL) (R506Q) mutation is the most common genetic cause of deep venous thrombosis, but its association with RPL has been inconsistent in studies arising from non-Western countries. The present metanalysis was aimed to determine whether an association exists between FVL and RPL in the Middle East.

METHODS

We searched PubMed, MEDLINE Web of Science, Scopus, and Embase, evaluating the association between the FVL and RPL. The Middle East countries (Bahrain, Cyprus, Egypt, Iran, Iraq, Israel, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, The State  of Palestine, Syria, Turkey, The United Arab Emirates, and Yemen) were evaluated in succession. Raw data were extracted, and 19 case-control studies were included in our final analysis.

RESULTS

Overall, 2513 cases and 1836 controls in the Middle East showed a prevalence of FVL mutation as 12.6% and 4.9% in patients and controls, respectively. To evaluate the relationship between FVL mutation and RPL, we used Forest plot (random effect model) with the overall random OR of 2.37 (CI 95%: 1.50-3.75). FVL mutation was associated with a higher risk of RPL. In Iran, the OR was 1.90 (95% CI 1.04-3.45), and in Turkey, the OR was 3.01 (95% CI 1.10-8.23).

CONCLUSION

The results of our study support an association between FVL mutation status and RPL in women of the Middle East countries. It is recommended that specific policies include comprehensive testing for FVL mutation as a standard of care in women of the Middle East region with unexplained RPL.

Recurrent pregnancy loss: can factor V Leiden mutations be a cause

The role of Factor V Leiden (FVL) mutation in recurrent miscarriages has been disputed. It has been hypothesized that FVL mutation in patients with recurrent miscarriages is treatable. In this study, we evaluated 78 pregnant women for FVL mutations, among whom 50 had a history of recurrent miscarriages. Only 1 (2%) of the woman was positive for heterozygous FVL mutation. The incidence of FVL mutations in patients with recurrent pregnancy loss had an odds ratio of 1.72 (95% confidence interval, 0.0681–43.8257; P>0.05). However, the findings were not statistically significant. Thus, we suggest that FVL mutation study may not be included in the battery of tests for recurrent miscarriages in the Indian population.

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.

Etiology of Recurrent Pregnancy Loss in Saudi Females

Objective:

The aim of our retrospective study was to assess the etiology of recurrent pregnancy loss (RPL) in Saudi couples attending a specialized RPL clinic at King Fahad Hospital of the University, Al-Khobar, Saudi Arabia.

Patients and Methods:

A total of 59 couples attending the RPL clinic between January 2010 and December 2013 and who had completed their workup and investigations for RPL were included in the study. Data were collected from patients’ charts and computer-based laboratory results.

Results:

Protein S deficiency was found in 47% of patients, a chromosomal abnormality in 6.7%, uterine abnormality in 12%, antiphospholipid syndrome (APS) in 12%, and antithrombin III and Protein C deficiency in 1.7%. However, no patient had Factor V Leiden mutation. In 39% of the patients, there was no identifiable cause, and therefore, they had been diagnosed as unexplained RPL.

Conclusion:

The most common cause of RPL was Protein S deficiency followed by congenital uterine anomalies and APS. Almost 40% of couples with RPL remain with unknown etiology.

Prevalence of thromogenic gene mutations in women with recurrent miscarriage: A retrospective study of 1,507 patients

Objective

Thromogenic gene mutations has been thought to be associated with recurrent pregnancy loss in women in Turkey. The aim of this study was to investigate the prevalence of thromogenic gene mutations such as factor V Leiden (FVL, G1691T), prothrombin (G20210A), and the methylene tetrahydrofolate reductase (MTHFR, C677T) mutation in women with recurrent pregnancy loss.

Methods

This descriptive study was carried out in the Department of Obstetrics and Gynaecology, Harran University School of Medicine, and included a total of 1,507 women with histories of recurrent pregnancy loss between January 2010 and June 2013. The mutations were assessed by using the polymerase chain reaction.

Results

The homozygous mutation frequencies of FVL, prothrombin, and MTHFR were found to be 3 (0.20%), 0 and 125 (8.29%), and the heterozygous mutation frequencies were 83 (5.51%), 61 (4.05%), and 612 (40.61%), respectively. Among the 86 FVL mutation patients, 38 also had accompanying prothrombin and MTHFR mutations.

Conclusion

Since the homozygous forms of the FVL-prothrombin gene mutations have low incidences and MTHFR mutation is similar to a healthy population, preconceptional thromogenic gene mutations screening seems to be controversial.

Evaluation of GenoFlow Thrombophilia Array Test Kit in its detection of mutations in Factor V Leiden (G1691A), prothrombin G20210A, MTHFR C677T and A1298C in blood samples from 113 Turkish female patients

Thrombophilia is a heritable blood disease characterized by an increased tendency to form abnormal blood clots that can block blood vessels. In obstetrics and gynecology, it has been shown by a number of reports that a proportion of recurrent miscarriages involve thrombophilia-related mutations, in particular, Factor V G1691A, prothrombin G20210A, and MTHFR C677T and A1298C. In this study, we examined the frequency of these four mutations in 113 female Turkish patients who had prior complications in pregnancy, using the DiagCor GenoFlow Thrombophilia Array Test kit. Heterozygous MTHFR C677T and A1298C mutations were detected in 46% of the patients, and among these patients, 60% of them carried double heterozygous mutations. In contrast, the heterozygous Factor V G1691A and prothrombin G20210A were detected only in a smaller number of patients, respectively, 13% and 3%. The GenoFlow kit demonstrated 100% concordance with results from Sanger sequencing, which can be translated into sensitivity and specificity both at 100% within this series of patients.

Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphism in Iranian Women With Idiopathic Recurrent Pregnancy Losses

BACKGROUND

Recurrent pregnancy loss (RPL) is a serious problem for pregnancy. There is evidence that vascular complications play a principal role in RPL. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. Polymorphisms (C677T, A1298C) of MTHFR gene are associated with decreased MTHFR activity.

OBJECTIVES

The aim of this study was to determine the association between MTHFR polymorphisms (C677T and A1298C) and recurrent pregnancy loss (RPL) in Iranian women.

MATERIALS AND METHODS

In this case-control study, blood samples were obtained from patients who had three or more consecutive pregnancy losses before the 22(nd) week of pregnancy (n = 204). The control group consisted of 116 age-matched women with at least one alive child and without any history of pregnancy loss or other gestational complications (n = 116). Following DNA extraction, samples were tested for MTHFR C677T and A1298C polymorphisms using the reverse hybridization method.

RESULTS

The prevalence of 677TT mutation was 8.8% (18/204) in the patient group and 8.6% (10/116) in the control group (P = 0.434). The prevalence of 1298CC mutation was 12.3 % (25/204) in the patient group and 8% (9/116) in the control group (P = 0.155). Investigation of the distributions of various genotypes of MTHFR C677T and A1298C did not indicate a significant difference between patients with RPL and healthy control subjects.

CONCLUSIONS

The results suggest that MTHFR mutations might not be associated with RPL in the examined population.

Evaluation of Factor V G1691A, prothrombin G20210A, Factor XIII V34L, MTHFR A1298C, MTHFR C677T and PAI-1 4G/5G genotype frequencies of patients subjected to cardiovascular disease (CVD) panel in south-east region of Turkey

Cardiovascular disease (CVD) risk factors, such as arterial hypertension, obesity, dyslipidemia or diabetes mellitus, as well as CVDs, including myocardial infarction, coronary artery disease or stroke, are the most prevalent diseases and account for the major causes of death worldwide. In the present study, 4,709 unrelated patients subjected to CVD panel in south-east part of Turkey between the years 2010 and 2013 were enrolled and DNA was isolated from the blood samples of these patients. Mutation analyses were conducted using the real-time polymerase chain reaction method to screen six common mutations (Factor V G1691A, PT G20210A, Factor XIII V34L, MTHFR A1298C and C677T and PAI-1 -675 4G/5G) found in CVD panel. The prevalence of these mutations were 0.57, 0.25, 2.61, 13.78, 9.34 and 24.27 % in homozygous form, respectively. Similarly, the mutation percent of them in heterozygous form were 7.43, 3.44, 24.91, 44.94, 41.09 and 45.66%, respectively. No mutation was detected in 92 (1.95%) patients in total. Because of the fact that this is the first study to screen six common mutations in CVD panel in south-east region of Turkey, it has a considerable value on the diagnosis and treatment of these diseases. Upon the results of the present and previous studied a careful examination for these genetic variants should be carried out in thrombophilia screening programs, particularly in Turkish population.

Thrombophilic Mutations and Polymorphisms, Alone or in Combination, and Recurrent Spontaneous Abortion

Generally, recurrent spontaneous abortions (RSAs) have no identifiable cause; yet, vascular alterations during pregnancy may be associated with pregnancy loss. Therefore, we evaluated the association between thrombophilic mutations and RSAs. This case–control study was conducted in 112 patients who had RSAs and 98 health control women. Genomic DNA was extracted from whole blood, and polymorphism genotyping was conducted using polymerase chain reaction. The following 6 genetic variants were analyzed: factor V Leiden, prothrombin mutation, methylenetetrahydrofolate reductase C677T and A1298C, plasminogen activator inhibitor type 1 (4G>5G), and factor XIII G103T (V34L). No correlations were found in any of the investigated polymorphisms. Moreover, 35.0% of cases and 25.5% of controls had at least 2 mutations in combination, and 4.8% of cases and 5.1% of controls had 3, but these combinations were not associated with additional risk. In conclusion, we found no association between the polymorphisms studied and the occurrence of RSAs.

Inherited thrombophilia and recurrent pregnancy loss

Background:

Recurrent pregnancy loss (RPL) is a common health problem. The polymorphisms G20210A of prothrombin gene (FII G 20210A), and G 1691A of factor V gene (Factor V Leiden, FVL) are the most extensively studied thrombophilic mutations in association to recurrent miscarriage.

Objectives:

To determine the frequency of FII G20210A and FVL polymorphisms as well as protein C and protein S deficiency in a series of patients with RPL compared with control group.

Patients and Methods:

The study group included 90 randomly selected patients with three or more consecutive miscarriages with the same partner in <20 weeks gestation in 2012. The control population consisted of 44 age-matched women with at least one live born children and no history of pregnancy loss. Functional activity of protein C and S, activated protein C resistance, FVL assay by polymerase chain reaction and prothrombin gene mutation were assessed. The polymorphism frequencies were recorded for each group and comparisons were made.

Results:

The mean functional activity of protein C and protein S were not significantly different between case and control groups (P >0.05). Frequency of protein C deficiency was also not significantly different between the case and control groups (P=0.906), but frequency of protein S deficiency was significantly higher in patients than controls (P=0.03). Genotype pattern of the patients and healthy individuals were not significantly different with regard to either FVL or Prothrombin G20210A (P > 0.05).

Conclusions:

We determined a significant higher frequency of protein S deficiency in patients with RPL compared with controls. But the frequency of protein C deficiency and the frequency of two common thrombophilic mutations (Factor V Leiden and Prothrombin G20210A), were not significantly different between patients with recurrent miscarriage and healthy women.

Association between apolipoprotein E gene polymorphism and the risk of recurrent pregnancy loss: a meta-analysis

PURPOSE

The association between apolipoprotein E (ApoE) gene polymorphism and the risk of recurrent pregnancy loss (RPL) remains controversial. The present meta-analysis was performed to derive a precise estimate of the relationship.

METHOD(S)

We searched the PubMed, Embase, and Web of Science data- bases for studies related to the association between the ApoE genotype and the risk of RPL. We estimated the summary odds ratio (OR) with 95% confidence interval (CI) to assess the association.

RESULT(S)

Seven studies, including 2,090 RPL cases and 742 control samples, were identified. The results showed a significant association between ApoE E4 mutation and RPL risk (for E4 allele: OR =1.98, 95 %CI =1.14-3.43, P=0.499; for E2E3 vs. E3E3: OR =1.33, 95%CI =1.12-1.42, P=0.008; for E2E4 vs. E3E3: OR =1.26, 95 % CI =1.07-1.49, P=0.005).

CONCLUSION(S)

The meta-analysis suggests an association between ApoE E4 mutation and increased risk of RPL.

The association between thrombophilic gene mutations and recurrent pregnancy loss

PURPOSE

To determine whether the Factor V (1691G/A), Factor V HR2 (4070A/G), Prothrombin (20210G/A), PAI-1 (-675 I/D, 5G/4G), ACE (intron 16 I/D), Factor VII (Gln353Arg), Factor XIII (Val34Leu), β-fibrinogen (-455G/A), Glycoprotein Ia (807C/T), tPA (intron 8 D/I) gene mutations could be risk factors for recurrent pregnancy loss (RPL).

METHODS

Genotyping of thrombophilic gene mutations were carried out by amplification Refractory Mutation System-PCR (ARMS-PCR) method after DNA extraction.

RESULTS

We found that the mutant allele frequencies of Factor V (1691G/A), Factor V HR2 (4070A/G), Prothrombin (20210G/A), PAI-1 (-675 I/D, 5G/4G), Factor XIII (Val34Leu) and β-fibrinogen (-455G/A) were more seen in the case group compared with the healthy control; However, the difference between the two group is not statistically significant (p > 0.05). Whilst the mutant allele frequencies of other studied genes were lower in the case in comparison to the fertile control women (p > 0.05).

CONCLUSION

Taken together, our data has shown that the prevalence of thrombophilic gene mutations was similar in women with RPL and healthy controls. Therefore, it appears that further studies on large-scale population and other genetic variants will be needed to conclusively find candidate genes for RPL unknown etiology in the future.

Prevalence of 1691G>A FV mutation in females from Bosnia and Herzegovina--a preliminary report

Factor V is the liver-synthesized multidomain glycoprotein encoded by a gene localised on chromosome 1q23. The point mutation 1691G>A in this gene results in formation of an altered protein of V Factor resistant to activated protein C (APC) cleavage. This mutation alone is the most frequent cause of inborn thrombophilia and the most widely acknowledged genetic risk factor for venous thrombosis in a Caucasian population. This study was designed to provide the first estimate of the frequency of the allele 1691A FV in the Bosnian female population. The 1691G>A FV mutation was examined by polymerase chain reaction-restriction fragment length polymorphism, in a group of 67 women, mean age of 58.6 years with no history of cardiovascular incident. Our findings revealed an absence of the mutated allele 1691A FV in the studied group. This is the first report on the 1691G>A FV mutation in a population from Bosnia and Herzegovina. Further research is needed to establish prevalence of the mutated allele in the population from Bosnia and Herzegovina.

Hereditary thrombophilia, anti-beta2 glycoprotein 1 IgM, and anti-annexin V antibodies in recurrent pregnancy loss

PROBLEM

We investigated the beta2-glycoprotein I and anti-annexin V antibodies as anti-phospholipid-cofactor antibodies; and factor V G1691A Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations as hereditary thrombophilia in recurrent pregnancy losses (RPL).

METHOD OF STUDY

Study group consisted of 84 women with recurrent pregnancy loss and control group consisted of 84 women having at least one live birth.

RESULTS

Methylenetetrahydrofolate reductase C677T homozygous mutation was detected in 28.5% of the study group and in 14.2% of the controls, and the difference was highly significant (P < 0.001). Heterozygous mutation of this gene was found in 64.3% of the study population and in 38.1% of the controls, and difference in heterozygous mutation frequency was also significant (P < 0.001). Both homozygous and heterozygous mutations of PT G20210A and factor V G1691A were not different between the groups. There was no significant difference in anti-annexin V levels and anti-beta2-gp 1 levels of the groups.

CONCLUSION

We concluded that both homozygous and heterozygous mutations of MTHFR C677T were related with RPL in Caucasian women.

Can Factor V Leiden and prothrombin G20210A testing in women with recurrent pregnancy loss result in improved pregnancy outcomes?: Results from a targeted evidence-based review

Women with recurrent pregnancy loss are offered Factor V Leiden (F5) and/or prothrombin G20210A (F2) testing to identify candidates for anticoagulation to improve outcomes. A systematic literature review was performed to estimate test performance, effect sizes, and treatment effectiveness. Electronic searches were performed through April 2011, with review of references from included articles. English-language studies addressed analytic validity, clinical validity, and/or clinical utility and satisfied predefined inclusion criteria. Adequate evidence showed high analytic sensitivity and specificity for F5 and F2 testing. Evidence for clinical validity was adequate. The summary odds ratio for association of recurrent pregnancy loss with F5 in case-controlled studies was 2.02 (95% confidence interval, 1.60-2.55), with moderate heterogeneity and suggestion of publication bias. Longitudinal studies in women with recurrent pregnancy loss or unselected cohorts showed F5 carriers were more likely to have a subsequent loss than noncarriers (odds ratios: 1.93 and 2.03, respectively). Results for F2 testing were similar. For clinical utility, evidence was adequate that anticoagulation treatments were ineffective (except in antiphospholipid antibody syndrome) and had treatment-associated harms. The certainty of evidence is moderate (high, moderate, and low) that anticoagulation of women with recurrent pregnancy loss and F5/F2 variants would currently lead to net harms.

Prothrombin gene G20210A mutation and obstetric complications

OBJECTIVE

To estimate whether maternal carriage of the prothrombin gene G20210A mutation is associated with pregnancy loss, preeclampsia, placental abruption, or small for gestational age (SGA) neonates in a low-risk, prospective cohort.

METHODS

This was a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development factor V Leiden study, a multicenter, prospective, observational cohort of 5,188 unselected singleton gestations. A total of 4,167 first-trimester samples were available for analysis and were tested for the prothrombin G20210A mutation. Obstetric complications were compared between women with and without the prothrombin G20210A mutation by univariable and multivariable analysis.

RESULTS

A total of 157 (3.8%) women had the prothrombin gene mutation (156 heterozygous and one homozygous). Carriers of the prothrombin G20210A mutation had similar rates of pregnancy loss, preeclampsia, SGA neonates, and abruption compared with noncarriers. Results were similar in a multivariable analysis controlling for age, race, prior pregnancy loss, prior SGA neonates, and family history of thromboembolism. Three thromboembolic events occurred in women testing negative for the mutation.

CONCLUSION

There was no association between the prothrombin G20210A mutation and pregnancy loss, preeclampsia, abruption, or SGA neonates in a low-risk, prospective cohort. These data raise questions about the practice of screening women without a history of thrombosis or adverse pregnancy outcomes for this mutation.

LEVEL OF EVIDENCE

II.

A prospective case-control study analyzes 12 thrombophilic gene mutations in Turkish couples with recurrent pregnancy loss

PROBLEM

Recurrent pregnancy loss (RPL) is a heterogeneous disorder. The contribution of specific thrombophilic genes to the pathophysiology of RPL has remained controversial. We evaluated the prevalences of 12 thrombophilic gene mutations among homogenous Caucasian couples with RPL and fertiles.

METHOD

of study This was a prospective case-control study evaluating 272 women with RPL and 152 of their male partners, and a control group of 56 fertile couples. We investigated mutations including FV Leiden, factor V H1299R, factor II prothrombin G20210A, F XIII V34L, beta-fibrinogen -455G>A, plasminogen activator inhibitor-1, GPIIIa L33P (HPA-1 a/b L33P), MTHFR C677T, MTHFR A1298C, ACE I/D, Apo B R3500Q, and Apo E.

RESULTS

Overall, heterozygous mutations of FV Leiden, FXIII V34L, GPIIIa L33P, Apo E4, and prothrombin G20210A and homozygous mutations of PAI-1and MTHFR C677T were associated with RPL. There was no meaningful association between RPL and other studied genes.

CONCLUSION

In contrast to the other mutations and polymorphisms, FV Leiden, FXIII V34L, GPIIIa L33P, Apo E, prothrombin G20210A, PAI-1 and MTHFR C677T gene mutations may help to identify the couples at risk for recurrent pregnancy loss.

Paternal thrombophilic gene mutations are not associated with recurrent miscarriage

PROBLEM

Recurrent miscarriage (RM) affects 1-3% of couples. So far, diagnostic procedures are performed only in female patients. However, the main part of the placentary perfusion is encoded by both the maternal and the paternal genome.

METHOD OF STUDY

In this case-control study, German couples with two (n = 49) or three and more RM (n = 102) and 157 German control couples were analyzed for the factor V-Leiden 169 1G > A mutation (FVL), the prothrombin (PT) 202 10G > A substitution, and the 677C > T replacement in the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene.

RESULTS

No significant differences in the prevalence of the FVL, PT or MTHFR mutation were observed in male partners of RM patients and in control men [RM/control: FVL heterozygous 13/151 (8.6%): 14/157 (8.9%) (P = 0.9); PT heterozygous 2/151 (1.3%): 7/157 (4.5%) (P = 0.097); PT homozygous 0/151: 2/157 (1.3%); MTHFR homozygous 19/151 (12.6%): 18/157 (11.5%) (P = 0.12)]. This was also true for female RM patients. However, miscarriage during the embryonal period (5-10 weeks of gestation) was significantly associated with a maternal heterozygous FVL mutation (P = 0.014).

CONCLUSION

Recurrent miscarriage was not associated with paternal thrombophilia. Men of the control group showed an even higher incidence of the PT and MTHFR mutations. Abortions in the embryonic phase of fetal development were associated with a significantly higher incidence of maternal heterozygosity for FVL.