Factor V Leiden mutation in women with early recurrent pregnancy loss: a meta-analysis and systematic review of the causal association

Australasian recurrent pregnancy loss clinical management guideline 2024, part II

Part II of the Australasian guideline for the investigation and management of recurrent pregnancy loss (RPL) provides evidence-based guidance on the management of RPL provided. The implications of inherited and acquired thrombophilia with respect to RPL and suggestions for clinical management are provided. Autoimmune factors, including human leukocyte antigen, cytokines, antinuclear antibodies and coeliac antibodies, and guidance for management are discussed. Infective, inflammatory and endometrial causes of RPL are discussed in detail. Environmental and lifestyle factors, male factor and unexplained causes are outlined. Levels of evidence and grades of consensus are provided for all evidence-based statements.

Relationship Between Recurrent Pregnancy Loss With Unknown Etiology and Endoplasmic Reticulum Stress

INTRODUCTION

Recurrent pregnancy loss (RPL) is characterized by consecutive pregnancy losses before 20 weeks of gestation, with evolving definitions necessitating adjustments to prevent delays in couples' evaluation. Limited etiological data on RPL prompts comprehensive evaluations, often yielding no pathological findings. Emerging research implicates endoplasmic reticulum (ER) stress in various reproductive processes, yet its association with RPL remains understudied.

AIM

To evaluate ER stress in patients with RPL with unknown etiology by determining the plasma concentration of X-box binding protein-1 (XBP-1).

MATERIALS AND METHODS

A total of 45 patients aged 18 to 35 years with at least two pregnancy losses with unknown etiology before the completion of 20 weeks of gestation between March 2020 and September 2020 were included in the study group. The control group consisted of 45 healthy women with at least two previous live births, no pregnancy-associated complications, and no history of pregnancy loss or infertility. The XBP-1 levels were determined from serum samples. Statistical analyses assessed differences between groups, and receiver operating characteristic (ROC) curve analysis determined XBP-1's predictive value for RPL.

RESULTS

The mean XBP-1 concentration in the RPL group was significantly higher than in the control group (p < 0.001). The mean values were 2243.65 ± 9425.27 pg/mL and 1196.32 ± 4378.81 pg/mL, respectively. The use of XBP-1 levels for the prediction of RPL was evaluated. In an ROC curve analysis, the area under the curve was found to be 87% (95% CI: 80% to 94.8%). The specificity was 78%, the sensitivity was 88%, the positive likelihood ratio (LR) was 4, the negative LR was 0.15, the positive predictive value was 80%, and the negative predictive value was 87% for the cut-off XBP-1 level at 1364.68 pg/mL.

CONCLUSION

This study highlights the potential role of ER stress in RPL and proposes XBP-1 as a predictive biomarker for pregnancy loss. Understanding ER stress mechanisms in RPL could inform diagnostic and therapeutic strategies. Further research is essential to validate these findings and explore their clinical implications.

Association of inherited thrombophilia mutations and their combinations among palestinian women with unexplained recurrent miscarriage

BACKGROUND

Inherited thrombophilia (IT) has a complex pathophysiology and is associated with recurrent miscarriage (RM) by causing placental insufficiency and inhibiting fetal development. However, thrombophilia screening in unexplained RM cases is still questionable. This study aimed to investigate the association between the common eight IT mutations and their combinations among Palestinian women with unexplained RM.

METHODS

This is an unmatched case-control study with 200 women (100 unexplained RM cases, 100 controls). Eight common IT mutations namely Factor V Leiden (FVL), prothrombin gene (FII) G202120A, Methylenetetrahydrofolate Reductase (MTHFR) gene (C677T and A1298C), B-fibrinogen gene - 455G > A, FV HR2 A4070G, Plasminogen activator inhibitor 1 (PAI1) 5G/4G and Factor XIIIA (FXIIIA) V34L; were analyzed. The first five mutations were analyzed by Restriction Fragment Length Polymorphism PCR and the other three mutations were analyzed using Amplification Refractory Mutation System PCR.

RESULTS

The prevalence of the eight IT mutations among the control group was in the order PAI1 5G/4G (69%), MTHFR C677T (53%) and A1298C (47%), BFG - 455G > A (35%), FVL and FV HR2 (each 18%), FXIIIA V34L (16%) and FII G20210A (3%). Patients had a higher percentage of MTHFR A1298C (heterozygotes and mutant homozygote) compared to controls (p = 0.016). Frequencies of mutant alleles MTHFR A1298C (p < 0.001) and FXIIIA V34L (p = 0.009) were higher among patients compared to controls. No significant differences were observed for all other mutations or mutant alleles. Most patients (75%) and controls (75%) have 2-4 mutant alleles out of 8 mutant alleles studied, while 1% of patients and 2% of controls have zero mutant alleles. None of the combinations of the most often studied mutations (FVL, FII G20210A, MTHFR C1677T, and MTHFR A1298C) showed a significant difference between patients and controls.

CONCLUSIONS

There was a significant association between unexplained RM and the mutant alleles of MTHFR A1298C and FXIIIA V34L. No significant association was observed between unexplained RM and the combination of both mutant alleles for the mutations studied. This study is the first Palestinian report that evaluates eight inherited thrombophilia mutations and their alleles' combinations in unexplained RM cases.

Low-molecular-weight heparin in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection: A meta-analysis

INTRODUCTION

This meta-analysis aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) on pregnancy outcomes in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

MATERIAL AND METHODS

A systematic literature search of PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure was performed to identify randomized controlled trials (RCTs) comparing LMWH with no treatment or placebo published from database inception until February 19, 2023. Primary outcomes were the clinical pregnancy rate and implantation rate, and secondary outcomes were the live birth rate, miscarriage rate, and the risk of bleeding events. The certainty of the evidence was rated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Meta-analysis was conducted using STATA 14.0.

RESULTS

Five RCTs involving 1094 thrombophilic women receiving IVF/ICSI were finally included. Administration of LMWH was associated with statistically higher clinical pregnancy rate (4 RCTs, risk ratio [RR] 1.50, 95% confidence interval [CI] 1.23-1.82, p < 0.001, low certainty evidence), implantation rate (5 RCTs, RR 1.49, 95% CI 1.25-1.78, p < 0.001, very low certainty evidence), and live birth rate (2 RCTs, RR 2.15, 95% CI 1.60-2.89, p < 0.001, very low certainty evidence), but with statistically lower miscarriage rate (2 RCTs, RR 0.36, 95% CI 0.15-0.86, p = 0.021, very low certainty evidence). However, using LMWH was linked to a higher risk of bleeding events (2 RCTs, RR 2.36, 95% CI 1.49-3.74, p < 0.001, very low certainty evidence).

CONCLUSIONS

Very low certainty evidence suggests that administration of LMWH may benefit pregnancy outcomes in thrombophilic women receiving IVF/ICSI treatment, although it may also increase the risk of bleeding events. However, before putting our findings into practice, healthcare professionals should conduct an in-depth evaluation of the available evidence and specific patient situations. Furthermore, due to the low methodological quality of the included studies, more high-quality studies are needed to validate our findings in the future.

Recurrent Pregnancy Loss Etiology, Risk Factors, Diagnosis, and Management. Fresh Look into a Full Box

Recurrent pregnancy loss is a complex health challenge with no universally accepted definition. Inconsistency in definitions involves not only the number of spontaneous abortions (two or three) that are accepted for recurrent pregnancy loss but the types of pregnancy and gestational age at miscarriage. Due to the heterogeneity of definitions and criteria applied by international guidelines for recurrent pregnancy loss, the true incidence of recurrent miscarriage, which is reported to range from 1% to 5%, is difficult to estimate. Moreover, the exact etiology of recurrent pregnancy loss remains questionable; thus, it is considered a polyetiological and multifactorial condition with many modifiable and non-modifiable factors involved. Even after thoroughly evaluating recurrent pregnancy loss etiology and risk factors, up to 75% of cases remain unexplained. This review aimed to summarize and critically analyze accumulated knowledge on the etiology, risk factors, relevant diagnostic options, and management approach to recurrent pregnancy loss. The relevance of various factors and their proposed roles in recurrent pregnancy loss pathogenesis remains a matter of discussion. The diagnostic approach and the management largely depend on the etiology and risk factors taken into consideration by a healthcare professional as a cause of recurrent miscarriage for a particular woman or couple. Underestimation of social and health consequences of recurrent pregnancy loss leads to compromised reproductive health and psychological well-being of women after miscarriage. Studies on etiology and risk factors for recurrent pregnancy loss, especially idiopathic, should be continued. The existing international guidelines require updates to assist clinical practice.

Patients with severe coronavirus disease 2019 have high frequency of factor 5 Leiden and prothrombin gene mutations

We investigated the frequency of factor 5 Leiden (FVL) and prothrombin gene (PTG) mutations in patients with severe coronavirus disease 2019 (COVID-19). Our primary aim is to reveal whether these mutations are associated with severity of disease and mortality. A total of 249 patients were included in this cross-sectional study. Severe COVID-19 cases (with oxygen saturation of less than 90 mmHg and who received ventilation support invasively or noninvasively) were included. FVL and PTG mutations were identified by real time- PCR technique. Frequency of mutations for FVL was 11.7%, whereas for PTG was 3.5%. The frequency of FVL and PTG's mutations in our patient group was found to be significantly higher than the normal population ( P  < 0.0001, 0.004, respectively). There was no difference in the frequency of mutations of FVL and PTG between the patients ventilated - invasively and noninvasively. There was also no difference in D-dimer, ferritin, fibrinogen, ex status, and entubational status between the groups of FVL and PTG mutated and wild-type. To the best of our knowledge, it is the first time that we have examined the frequencies of FVL and PGM's mutations in severe COVID-19 disease on such a large scale. The frequencies of both mutations in severe COVID-19 patients were higher than in the healthy population. We believe that studies prospectively designed, including asymptomatic and mild COVID-19 patients, will provide more comprehensive information on the subject.

Recurrent miscarriage in a woman with congenital factor V deficiency: a case report

BACKGROUND

Factor V deficiency is a rare bleeding disorder that can be either congenital or acquired. Factor V deficiency mostly present with mucosal bleeding. Coagulation factor V does not increase considerably during normal gestation. Since pregnancy can be threatened by blood clotting disorders, abnormal changes in coagulation factors level can pose challenges to pregnant women.

CASE PRESENTATION

We report a 40-year-old pregnant woman with prolonged gingival bleeding and epistaxis at 28 weeks of pregnancy. Her past medical history included two unexplained abortions. Physical examination was unremarkable, but the blood test showed elevated PT and PTT with a considerable decrease in factor V activity, while other factors were within normal range. Subsequently, the patient was diagnosed with congenital factor V deficiency. After treatment with fresh frozen plasma, she underwent vaginal delivery and a baby with factor V deficiency was born.

CONCLUSIONS

This is the second report of recurrent miscarriage in congenital factor V deficiency patients. Clinicians should consider the possibility of factor V deficiency in women with a history of idiopathic miscarriage even in patients without any symptoms.

Understanding recurrent pregnancy loss: recent advances on its etiology, clinical diagnosis, and management

Recurrent pregnancy loss (RPL) has become an important reproductive health issue worldwide. RPL affects about 2%-3% of reproductive-aged women, and makes serious threats to women's physical and mental health. However, the etiology of approximately 50% of RPL cases remains unknown (unexplained RPL), which poses a big challenge for clinical management of these patients. RPL has been widely regarded as a complex disease where its etiology has been attributed to numerous factors. Heretofore, various risk factors for RPL have been identified, such as maternal ages, genetic factors, anatomical structural abnormalities, endocrine dysfunction, prethrombotic state, immunological factors, and infection. More importantly, development and applications of next generation sequencing technology have significantly expanded opportunities to discover chromosomal aberrations and single gene variants responsible for RPL, which provides new insight into its pathogenic mechanisms. Furthermore, based upon patients' diagnostic evaluation and etiologic diagnosis, specific therapeutic recommendations have been established. This review will highlight current understanding and recent advances on RPL, with a special focus on the immunological and genetic etiologies, clinical diagnosis and therapeutic management.

A Systematic Review and Meta-Analysis of the Association between the FV H1299R Variant and the Risk of Recurrent Pregnancy Loss

This study evaluated the association between the H1299R factor V (FV) variant (rs1800595) and recurrent pregnancy loss (RPL). Pubmed (MEDLINE) and Embase (OVID) bibliographic databases were searched from the inception to 31 May 2022 to identify suitable articles according to PRISMA and MOOSE guidelines. We included observational studies, case-control studies, cross-sectional studies, and cohort studies reporting a numerical and well-distinguished Het or Hom status of the H1299R variant obtained through PCR or other biochemical techniques and comparing RPL patients with a healthy control group. The review protocol was registered at PROSPERO (CRD42022330077). Two authors independently screened studies, extracted data, and carried out the risk of bias assessment using the Newcastle Ottawa scale (NOS). A meta-analysis was performed with RevMan software Version 5.4 using an odds ratio (OR) with an M-H, random effect, and 95% CI. We included 13 clinical studies for a total of 1669 RPL patients and 1466 healthy women as a control group. H1299R variant was slightly associated with RPL albeit without significance (OR 1.18, 95% CI: 0.78-1.80, p = 0.44). Subgroup analyses considering H1299R in heterozygosity (OR 1.13, 95% CI: 0.76-1.67, p = 0.56) and in homozygosity (OR: 2.11, 95% CI: 0.74-6.01, p = 0.16) revealed a similar trend. Lastly, we evaluated the association between H1299R and RPL based on the number of previous miscarriages (≥2 or ≥3). This comprehensive systematic review and meta-analysis sheds light on the specific influence of the H1299R variant in the F5 gene on RPL, constituting valid support for medical care during pregnancy and genetic counseling.

Exome-Sequencing Identifies Novel Genes Associated with Recurrent Pregnancy Loss in a Chinese Cohort

Recurrent pregnancy loss (RPL) is a common reproductive problem affecting around 5% of couples worldwide. At present, about half of RPL cases remained unexplained. Previous studies have suggested an important role for genetic determinants in the etiology of RPL. Here, we performed whole-exome sequencing (WES) analysis on 100 unrelated Han Chinese women with a history of two or more spontaneous abortions. We identified 6736 rare deleterious nonsynonymous variants across all patients. To focus on possible candidate genes, we generated a list of 95 highly relevant genes that were functionally associated with miscarriage according to human and mouse model studies, and found 35 heterozygous variants of 28 RPL-associated genes in 32 patients. Four genes (FOXA2, FGA, F13A1, and KHDC3L) were identified as being strong candidates. The FOXA2 nonsense variant was for the first time reported here in women with RPL. FOXA2 knockdown in HEK-293T cells significantly diminished the mRNA and protein expression levels of LIF, a pivotal factor for maternal receptivity and blastocyst implantation. The other genes, with 29 variants, were involved in angiogenesis, the immune response and inflammation, cell growth and proliferation, which are functionally important processes for implantation and pregnancy. Our study identified several potential causal genetic variants in women with RPL by WES, highlighting the important role of genes controlling coagulation, confirming the pathogenic role of KHDC3L and identifying FOXA2 as a newly identified causal gene in women with RPL.

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

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

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.

Immunologic causes and thrombophilia in recurrent pregnancy loss

Certain miscarriages result from immunologic factors, but there is no clear identification of the precise causes of recurrent pregnancy loss (RPL). Miscarriages and RPL can arise from a disruption of maternal-fetal immune homeostasis. Remodeling of the maternal uterine spiral arteries is one of the key steps for normal growth and development of the fetus. An adequate oxygen supply is necessary for correct placentation, and it is accomplished by proper vascular changes. The development of fetal tissues creates a potential immunologic problem since the fetus can express paternal antigens and, in some cases, antigens of a gamete donor. The maternal immune system actively responds to fetal antigens, and dysregulation of this crosstalk could partly explain pregnancy complications such as miscarriages and RPL. RPL resulting from thrombophilia is primarily due to acquired thrombophilia, and therefore screening and treatment should be focused on antiphospholipid antibody syndrome.

Thrombophilia associated gene polymorphisms: Does use of medication, including anti-coagulants, minerals or folic acid, prevent the miscarriages?

OBJECTIVE

Recurrent pregnancy loss (RPL) has been associated with thrombophilia. The use of prophylactic treatments against thrombophilia becomes necessary in order to increase the live birth rates in women with RPL. The aim of this study was to genotype thrombophilia associated polymorphisms and investigates the benefit of prophylactic treatment on the clinical pregnancy outcomes of women with specific genotypes of these polymorphisms.

MATERIALS AND METHODS

A total of 62 women were included in this study. The polymorphisms associated with thrombophilia, including methyltetrahydrofolate reductase (MTHFR) 1298 and 677, Factor V Leiden (FVL) 1691, plasminogen activator inhibitor-1 (PA1-1) G/G and Factor II prothrombin 20,210, were genotyped using the real time PCR. The effect of prophylactic treatment using anti-coagulants of 0.4 mL dose of enoxaparin (3000-6000IU) and 75 mg dose of aspirin, 81 mg dose of aspirin, mineral of 15 mg dose of zinco c or10 mg dose of folic acid, was correlated with the genotypes of polymorphisms.

RESULTS AND CONCLUSION

The clinical pregnancy outcomes were significantly improved in patients with MTHFR 677CC genotype when treated with zinco c. Furthermore, treatment with 75 mg of aspirin resulted in higher negative pregnancy rates in patients with MTHFR A1298C genotypes. Therefore, the results of this study should be used to re-evaluate the clinical applications in women with miscarriages.

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.

Comparison between thrombophilic gene polymorphisms among high risk patients

Introduction. The purpose of this study was to compare the role of the thrombophilic variants among two groups of high risk patients with vascular disorders and recurrent pregnancy loss.

Methods. 200 patients, including 76 with thrombotic accidents and 124 with two or more idiopathic recurrent miscarriage during the first trimester, were tested for the presence of Factor V (F V) Leiden G1691A, Factor II (F II) G20210A, plasminogen activator inhibitor (PAI) 4G/5G, and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms using Real time polymerase chain reaction (RT – PCR) in the Laboratory of Medical Genetics, Varna, Bulgaria between June 2016 and May 2019. Frequencies of thrombophilic gene polymorphisms were compared among the two populations and to the expected genotype frequencies.

Results. Individuals with a history of vascular disorders had a significantly higher frequency of F V Leiden variant compared to women with recurrent miscariage. There was no statistical difference between the analyzed patients for the other three thrombophilic polymorphisms. The allelic frequencies and the expected genotype frequencies of the F V, F II and MTHFR polymorphisms were calculated according to Hardy-Weinberg equilibrium. The percentages of the homozygotes for F V and F II were higher than expected in the two groups of patients. For the MTHFR there was no difference.

Conclusion. F V Leiden remains the strongest risk factor for vascular disorders and recurrent pregnancy loss. Screening for this variant should be recommended to patients with thrombotic accidents and women with repeated miscarriage. The role of F II, PAI and MTHFR remains controversial.

Combined presence of coagulation factor XIII V34L and plasminogen activator inhibitor 1 4G/5G gene polymorphisms significantly contribute to recurrent pregnancy loss in Serbian population

Background

Recurrent pregnancy loss (RPL) is a heterogeneous condition affecting up to 5% of women of reproductive age. Inherited thrombophilia have been postulated as one of the causes of RPL. Here we examined the prevalence of nine thrombophilic gene polymorphisms among women with history of recurrent miscarriages and fertile controls.

Methods

The study included 70 women with history of at least three early pregnancy losses and 31 fertile controls with no miscarriages. We investigated mutations in genes responsible for clotting and fibrinolysis, including factor V (FV) Leiden, FV H1299R, factor II (FII) G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T and A1298C, factor XIII (FXIII) V34L, plasminogen activator inhibitor-1 (PAI-1) 4G/5G and endothelial protein C receptor (EPCR) H1 and H3 haplotypes using reverse polymerase chain reaction ViennaLab cardiovascular disease StrippAssays.

Results

Our results showed no significant increase in prevalence of tested polymorphisms in women with RPL. However, relative risk for PRL among women heterozygous for FXIII V34L was 2.81 times increased (OR 2.81, 95% CI 1.15-6.87, P=0.023). Haplotype analysis showed that combined presence of high-risk genotypes for FXIII and PAI-1 significantly increases risk for RPL (OR 13.98, CI 95% 1.11-17.46, P=0.044).

Conclusions

This is the first study in Serbian population that investigated prevalence of FVR2, A1298C, FXIII V34L and EPCR gene variants. Compound heterozygosity for FXIII V34L and PAI-1 4G is significant risk factor for recurrent miscarriage. Our results should be viewed in context of small case-control study, so further large prospective studies are need for confirmation of our findings.

Aspirin, low molecular weight heparin, or both in preventing pregnancy complications in women with recurrent pregnancy loss and factor V Leiden mutation

Objective: The aim of this study was to compare the effects of low molecular weight heparin (LMWH), LMWH plus low dose aspirin, or low dose aspirin only on pregnancy outcomes in recurrent pregnancy loss (RPL) patients with factor V Leiden mutation (FVLM).Materials and methods: A total of 2764 RPL patients were evaluated in for the etiology of RPL. Mutations in factor V Leiden homozygous and heterozygous were determined. Subsequently, 196 of these patients were diagnosed with FVLM and included in the study; of these 174 completed the study. At the sixth week of gestation of subsequent pregnancy participants were randomly distributed into three groups. Group A (n = 61) was composed of patients with an oral dose of 100 mg aspirin daily, Group B (n = 59) consisted of patients using 40 mg enoxaparin and 100 mg orally aspirin daily, and Group C (n = 54) included patients using 40 mg enoxaparin daily during pregnancy.Results: Among the 174 patients who completed the study, the live birth and miscarriage rates were similar for the three groups (p = .843 and p = .694, respectively). There was no significant difference among the groups in rates of eclampsia, placental abruption, intrauterine fetal growth restriction and gestational diabetes mellitus. The number of preeclamptic patients was significantly higher in Group A than Groups B and C. The levels of preterm birth was significantly higher in Group A than Groups B and C.Conclusion: Using low dose aspirin, LMWH plus aspirin, or LMWH alone yielded comparable live birth rates in RPL patients with FVLM. However, LMWH decreased the risk of preeclampsia in this group of patients. LMWH might therefore have a preventive role regarding preeclampsia.

ACOG Practice Bulletin No. 197: Inherited Thrombophilias in Pregnancy

Inherited thrombophilias are associated with an increased risk of venous thromboembolism and 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. This Practice Bulletin has been revised to provide additional information on recommendations for candidates for thrombophilia evaluation, updated consensus guidelines regarding the need for prophylaxis in women with an inherited thrombophilia during pregnancy and the postpartum period, and discussion of new published consensus guidelines from the Society for Obstetric Anesthesia and Perinatology addressing thromboprophylaxis and neuraxial anesthetic considerations in the obstetric population.

Rationale and design of two prospective, multicenter, observational studies on reproductive outcome in women with recurrent failures after spontaneous or assisted conception: OTTILIA and FIRST registries

Background

Spontaneous pregnancy loss and implantation failure after assisted reproductive technologies (ART) are very common occurrences. Although 50–60% of all cases remains unexplained, various predisposing factors, including thrombophilias, have been identified. Thus, the potential benefit of a prophylaxis with low-molecular-weight heparins in improving outcomes has been often investigated over the years. However, the majority of studies are observational and results from randomized clinical trials (RCTs) are inconclusive, probably due to heterogeneity and limited sample size. To cover these unmet needs and to have further data mainly based on the real-life clinical management, we designed these multicenter registries.

Methods

OTTILIA (Observational sTudy on antiThrombotic prevention in thrombophILIA and pregnancy loss) and FIRST (recurrent Failures in assIsted Reproductive Techniques) registries are two prospective, multicenter, observational studies to evaluate pregnancy or ART outcomes in consecutive women with previous reproductive failures after spontaneous or assisted conception, respectively. All enrolled women are observed from their first visit after positive pregnancy test (OTTILIA) or before commencing a new ART cycle (FIRST) until the end of pregnancy or ART procedure (negative pregnancy test/end of pregnancy, if successful cycle), respectively. Data are collected by means of questionnaires and recorded in a central database. Follow-up investigations are performed during hospital stay, routine clinical follow-up visits or telephone interviews. Primary outcome is live birth rate in the OTTILIA register and clinical pregnancy rate in the FIRST.

Discussion

Although RCTs are the ‘gold standard’ for evaluating treatment outcomes, we believe that our registries represent a valid alternative in improving knowledge on mechanisms involved in reproductive failures and supporting future clinical decisions.

Trial registration

NCT 02385461, retrospectively registered 5 March 2015 (OTTILIA); NCT 02685800, registered 10 February 2016 (FIRST).

The interaction effect of angiogenesis and endothelial dysfunction-related gene variants increases the susceptibility of recurrent pregnancy loss

PURPOSE

The role of genetic polymorphisms in the pathogenesis of recurrent pregnancy loss (RPL) has been studied intensively. Complex diseases, including miscarriage, are believed to have a polygenic basis, and gene-gene interactions can play a significant role in the etiology of the disease. This study was conducted to investigate the association of gene-gene interactions with angiogenesis, endothelial dysfunction-related gene polymorphisms, and RPL.

METHODS

A case-control study was conducted with 253 unrelated RPL patients with 2 or more spontaneous pregnancy losses and 339 healthy women with no history of pregnancy complications. Genotyping of single-nucleotide polymorphisms (SNPs) was performed using real-time polymerase chain reaction (real-time PCR), restriction fragment length polymorphism (RFLP), or allele-specific polymerase chain reaction methods.

RESULTS

The genotypes 677TT of the MTHFR gene, 936TT, 936CT, and 634CC, 634GC of the VEGF gene, and allele 894T of the NOS3 gene were associated with a predisposition to RPL in the Russian population. A significant role of additive and epistatic effects in the gene-gene interactions of the SNPs of SERPINE-1, ACE, NOS3, MTHFR, and VEGF genes in RPL was demonstrated.

CONCLUSIONS

The results showed that gene-gene interactions are important for RPL susceptibility. Additionally, analysis of the genotype combinations of several allelic variants provides more information on RPL risk than analysis of independent polymorphic markers.

Direct blood PCR: TaqMan-probe based detection of the venous thromboembolism associated mutations factor V Leiden and prothrombin c.20210G>A without DNA extraction

BACKGROUND

Practically, the initial step of genetic analysis is the extraction of DNA from blood or other cells, which is often time consuming and cost-intensive. We aimed at establishing a real-time PCR protocol for the detection of the venous thromboembolism associated mutations factor V Leiden (F5 c.1691G>A; p.R506Q) and prothrombin (F2) c.20210G>A from whole blood, without DNA extraction.

METHODS

F5 c.1691G>A (p.R506Q) and F2 c.20210G>A mutations were determined in 205 EDTA anti-coagulated whole blood samples from patients who underwent routine clinical genotyping using the DirectBlood Genotyping PCR Kit (myPOLS Biotec, Konstanz, Germany) together with in-house developed TaqMan primer-probe assays.

RESULTS

Validity score values of genotype calls using whole blood were similar and did not significantly differ compared to those using genomic DNA as substrate in PCR. Mutation analysis of 205 whole blood samples showed a negligible PCR dropout rate (one in 410 reactions) and were in 100% concordance with results obtained by conventional genotyping.

CONCLUSION

We successfully established a robust and valid real-time PCR protocol for the detection of the venous thromboembolism associated mutations F5 c.1691G>A (p.R506Q) and F2 c.20210G>A directly from whole blood.

Thrombophilia and Recurrent Pregnancy Loss: The Enigma Continues

Background

Thrombophilic gene polymorphism is known to be a risk factor for recurrent pregnancy loss (RPL), but few studies have confirmed a possible role of thrombophilic genes polymorphism in RPL risk. This study was conducted to understand the relationship of the mutations of some thrombophilia-associated gene polymorphism (heterozygous/homozygous) with RPL. We compared patients with 2 abortions to patients with 3 or more abortions among Turkish women.

Material/Methods

In this study, patients previously diagnosed with habitual abortus at Obstetrics and Gynecology outpatient clinics in Turkey between 2012 and 2016 were included. In their peripheral blood, we detected factor V Leiden H1299R, prothrombin G20210A, MTHFR C677T, MTHFR A1298C, PAI-1 4G/5G, and PAI-1 4G/4G gene mutations.

Results

In this study, we have observed statistically meaningful data (P<0.01) related to the relationship between RPL and thrombophilia-associated gene polymorphisms such as heterozygous factor V Leiden H1299R, heterozygous prothrombin G20210A, PAI-1 4G/5G, and PAI-1 4G/4G.

Conclusions

We found that diagnosis of thrombophilic genes polymorphism is useful to determine the causes of RPL, recognizing that this multifactorial disease can also be influenced by various acquired factors, including reproduction-associated risk factors and prolonged immobilization.

Association of Factor V Leiden and Prothrombin G20210A Polymorphisms in Women with Recurrent Pregnancy Loss in Isfahan Province, Iran

Background:

Maternal thrombophilia has been identified as a risk factor for recurrent pregnancy loss (RPL). The aim of this study was to investigate the association between prothrombin G20210A and factor V Leiden (FVL) polymorphisms in women with RPL and a control group of parous women in Isfahan province of Iran.

Methods:

We studied 250 women with idiopathic RPL and 116 control cases. Prothrombin and FVL different genotypes were determined using polymerase chain reaction and reverse hybridization technique.

Results:

The frequencies of heterozygous mutation prothrombin G20210A were 6% and 0.9%, respectively (P = 0.025), in cases compared to the control group. The frequencies of homozygous mutation prothrombin G20210A were 0.4% and 0%, respectively, in cases compared to controls (P = 0.02). The prothrombin mutation was significantly higher in cases compared to the control group (odds ratio 8.81; 95% confidence interval: 1.16–66.62). There was no significant difference between the FVL mutation and pregnancy loss.

Conclusions:

The results indicated a significant higher frequency of prothrombin G20210A in women with RPL in comparison with controls. Our data suggest that the prothrombin G20210A mutation, but not the FVL mutation, may be an unrecognized cause of RPL in our population.

Association between Thrombophilic Genes Polymorphisms and Recurrent Pregnancy Loss Susceptibility in the Iranian Population: a Systematic Review and Meta-Analysis

Studies have indicated that thrombophilic genes polymorphisms are associated with recurrent pregnancy loss (RPL) in the Iranian population. We aimed to evaluate the precise association between thrombophilic genes polymorphisms (MTHFR C677T, MTHFR A1298C, Prothrombin G20210A, FVLG1691A, and PAI-1 4G/5G) and RPL risk in the Iranian population. PubMed, Web of Science, Google Scholar, and ISC were searched for eligible articles published up to April 1, 2017. In total, 37 case-control studies in 18 relevant publications were selected: 1,199, 1,194, 630, 830, and 955 RPL cases and 1,079, 1079, 594, 794, and 499 controls for MTHFR C677T, MTHFR A1298C,Prothrombin G20210A, FVL G1691A, and PAI-1 4G/5G, respectively. The results indicated a significant increased risk of RPL in all genetic models in the population. Also, Prothrombin G20210A and FVL G1691A as well as PAI-1 4G/5G polymorphisms were associated with RPL risk in the Iranian population. Hence, thrombophilic genes polymorphisms are associated with an increased RPL risk in the Iranian population.

Thrombogenesis in Thrombophilic Pregnancy: Evaluation of Low-Molecular-Weight Heparin Prophylaxis

The aim of this study is to investigate thrombogenesis and the hypercoagulable changes in pregnant women affected by thrombophilia who received low-molecular-weight heparin (LWMH) prophylaxis. We included 21 pregnant women affected by thrombophilia treated with LWMH and 20 nontreated normal pregnant women as the control group. The sample group of thrombophilic pregnant women included different conditions (factor V Leiden mutation, protein C deficiency, protein S deficiency, antiphospholipid antibodies syndrome, and combined defects). Three blood samples were collected during pregnancy (i.e., at 16, 20, and 24 weeks) and tested for activated partial thromboplastin time and prothrombin fragment F1 + 2 (F1 + 2); anti-FXa activity was tested only in treated thrombophilic pregnant women. F1 + 2 levels progressively increased during pregnancy in both study groups. However, the F1 + 2 increase in women exposed to heparin prophylaxis was significantly lower than that in normal pregnant women in all 3 measurements carried out during gestation (p < 0.05); a statistically significant inverse correlation between F1 + 2 levels and anti-Xa activity (R = -0.8575, p < 0.05) was observed in treated women during pregnancy. Our findings suggest that F1 + 2 in addition to anti-Xa measurement could be used to adjust LWMH prophylaxis, at least in high-risk pregnant women.

Thrombophilia and assisted reproduction technology-any detrimental impact or unnecessary overuse?

PURPOSE

The aim of this study is to provide an overview of the studies investigating a possible association between thrombophilia and assisted reproductive technology (ART) outcome.

METHODS

This is a literature review.

RESULTS

Congenital thrombophilias (CoT) are reported to be associated with pregnancy loss. However, the association between CoT and early pregnancy loss is weak and does not necessarily support causation. CoT are more likely to be associated with late fetal loss. Even though data pooled from case-control and cohort studies suggest an increased risk of ART failure in women with CoTs, there seems no association when the analysis is confined to better quality cohort studies. The evidence supporting anticoagulation to improve ART outcome in CoT carriers is weak. Likewise, studies on antiphospholipid antibodies (APAs) and ART outcome suffer from multiple methodological limitations and a detrimental impact of APA positivity is controversial. Empirical administration of heparin or low molecular weight heparin to women with recurrent ART failures is supported by weak evidence. Importantly, thrombophilias are likely to increase thrombotic complications after ovarian stimulation for ART.

CONCLUSIONS

Current evidence does not support routinely testing for or treatment of thrombophilia in the setting of ART nor in couples with implantation failure. A careful personal and family history should be obtained and a risk assessment for thrombotic complications should be made in every woman undergoing ovarian stimulation. If positive, testing for thrombophilia is warranted.

Etiologic characteristics and index pregnancy outcomes of recurrent pregnancy losses in Korean women

OBJECTIVE

The goal of this study was to evaluate the etiologies and clinical outcomes of Korean recurrent pregnancy loss (RPL) patients. And also, we investigated the differences between primary and secondary RPL patients, between two and three or more pregnancy losses.

METHODS

One hundred seventy eight women diagnosed as RPL were enrolled. We performed chromosomal analysis, thyroid stimulating hormone, prolactin, blood glucose, plasminogen activator inhibitor-1, natural killer cell proportion, anticardiolipin antibodies, antiphospholipid antibodies, lupus anticoagulant, anti-β2glycoprotein-1 antibodies, antinuclear antibody, protein C, protein S, antithrombin III, homocysteine, MTFHR gene, factor V Leiden mutation, and hysterosalphingography/hysteroscopic evaluation.

RESULTS

The mean age was 34.03±4.30 years, and mean number of miscarriages was 2.69±1.11 (range, 2 to 11). Anatomical cause (13.5%), chromosomal abnormalities (5.6%), and endocrine disorders (34.3%) were observed in RPL women. Elevated natural killer cell and antiphospholipid antibodies were observed in 43.3% and 7.3% each. Among of 178 women, 77 women were pregnant. After management of those women, live birth rate was 84.4% and mean gestational weeks was 37.63±5.12. Women with three or more RPL compared with women with two RPL had more common anatomical cause such as intrauterine adhesions and lower rates of spontaneous pregnancy. Compare with secondary RPL women, immunological abnormalities were more common in primary RPL. However, miscarriage rates were not different.

CONCLUSION

Immunological factor including autoimmune and alloimmune disorders was most common etiology of RPL. Inherited thrombophilia showed different patterns with other ethnic countries. Miscarriage rates were not different between primary and secondary RPL, or between two and three or more miscarriages group.