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

The relevance of prothrombotic genetic variants in women who experienced pregnancy loss or embryo implantation failure: A retrospective analysis of 1922 cases

OBJECTIVE

The aim of our study was that to assess the allelic and genotype frequencies of nine prothrombotic gene variants in patients with a history of pregnancy loss and recurrent pregnancy loss (RPL). Women who underwent assisted reproductive technology (ART) with ongoing pregnancy and those with recurrent implantation failure (RIF) were also included.

METHODS

Nine prothrombotic gene variants were evaluated: factor V Leiden (FVL), factor V, H1299R variant (FVR2), factor II (FII) G20210A, methylene-tetrahydrofolate reductase (MTHFR) C677T and A1298C, beta-fibrinogen -455G>A, factor XIII (FXIII) V34L, human platelet antigen-1 (HPA-1) L33P variants, and plasminogen activator inhibitor-1 (PAI-1) 4G/5G. The following study groups were assessed: (1) women who experienced one (n = 334) or two (n = 264) episodes of pregnancy loss; (2) 468 women who experienced RPL; (3) 214 women who underwent ART followed by ongoing pregnancies; and (4) 282 women who experienced RIF after ART, that is, three or more consecutive implantation failures following high-quality embryo transfers to the uterus with an appropriate endometrium. As control group, 430 subjects from the general population were enrolled.

RESULTS

FVL, the -455G>A variant of beta-fibrinogen, and PAI-1 4G were associated with a higher risk of developing RPL compared with the general population. Furthermore, FVL, FVR2, FII G20210A and MTHFR C677T conferred a significantly higher risk of RIF in women who performed ART compared with the general population. No statistical differences between the general population and other study groups were observed.

CONCLUSIONS

Specific prothrombotic genetic variants are more frequently expressed in women with RPL and RIF, supporting their role in the development of polimicrothrombosis and impairing the invasion during embryo implantation.

Thrombophilic gene polymorphisms and recurrent pregnancy loss: a systematic review and meta-analysis

PURPOSE

Recurrent pregnancy loss (RPL) is affecting 1-4% of women who conceive approximately, and no cause could be found in more than 50% of women suffering from RPL. Inherited thrombophilias have got increasing attention in women with unexplained RPL, so we aim to explore the relationship among these most common thrombophilic polymorphisms and RPL through a literature review and meta-analysis.

METHODS

Observational studies from PubMed, Embase, Cochrane, and Web of Science from 1997 to 7 April 2022 were searched. For each genetic variant, a fixed or random-effect model was used according to the heterogeneity test to calculate pooled ORs and 95% CIs for both dominant and recessive genetic models. Egger's line regression test was used to assess publication bias. The quality of the included articles was assessed by the Newcastle Ottawa scale.

RESULTS

A total of 124 articles comprising 17,278 RPL patients and 16,021 controls were included. Results showed that hyperhomocysteinemia (MTHFR) C677T (dominant model: OR, 1.43; 95% CI, 1.25-1.64; recessive model: OR, 1.60; 95% CI, 1.36-1.87), MTHFR A1298C (dominant model: OR, 1.66; 95% CI, 1.26-2.18; recessive model: OR, 1.79; 95% CI, 1.42-2.26), PAI-1 4G/5G (dominant model: OR, 1.67; 95% CI, 1.36-2.06; recessive model: OR, 1.80; 95% CI, 1.39-2.32), angiotensin-converting enzyme I/D (OR, 1.23; 95% CI, 1.00-1.53), Factor XIII V34L (OR, 1.38; 95% CI, 1.02-1.87), and β-fibrinogen-455G/A (OR, 1.60; 95% CI, 1.02-2.51) were significantly associated with RPL.

CONCLUSION

This study provides potentially useful clinical markers to evaluate the risk of RPL or to help unexplained RPL patients identify possible causes, which may allow for targeted treatment.

Evaluation of Patients with Neonatal Thrombosis

The aim of the study is to characterize acquired and genetic risk factors and to give an account of the hereditary thrombophilia panel in neonatal thrombosis. All newborns diagnosed with neonatal thrombosis in a level III NICU were included in this retrospective cohort study. A total of 1850 patients were admitted to the NICU during the 5-y period; and 11 patients were diagnosed with thrombosis (0.58%). The most common risk factors were central venous catheter placement, hypoxia and prematurity and related complications, and sepsis. Four patients were investigated regarding the inherited risk factors for thrombosis. In these 4 patients, homozygous A1298C alleles of MTHFR and heterozygous FXIIIV34L mutations; homozygous PAI-SERPINE1 and heterozygous MTHFRA1298C mutations; compound heterozygous mutations of MTHFRC677T and MTHFRA1298C; and compound heterozygous mutations of MTHFRC677T, MTHFRA1298C, and PAISERPINE1 were detected respectively. In conclusion, neonatal thrombosis is multifactorial; newborns with acquired risk factors may also have hereditary risk factors. TRIAL INFORMATION: ClinicalTrials.govIdentifier: NCT05367466.

Non-Invasive and Mechanism-Based Molecular Assessment of Endometrial Receptivity During the Window of Implantation: Current Concepts and Future Prospective Testing Directions

Suboptimal endometrial receptivity and altered embryo-endometrial crosstalk account for approximately two-thirds of human implantation failures. Current tests of the window of implantation, such as endometrial thickness measurements and the endometrial receptivity assay, do not consistently improve clinical outcomes as measured by live birth rates. Understanding the mechanisms regulating the endometrial receptivity during the window of implantation is a critical step toward developing clinically meaningful tests. In this narrative review, the available literature is evaluated regarding mechanisms that regulate the endometrial receptivity during the window of implantation and the current tests developed. Overall, both animal and human studies point to five possible and interrelated mechanisms regulating the endometrial window of implantation: suitable synchrony between endometrial cells, adequate synchrony between the endometrium and the embryo, standard progesterone signaling and endometrial responses to progesterone, silent genetic variations, and typical morphological characteristics of the endometrial glands. The biological basis of current clinical markers or tests of window of implantation is poor. Future studies to elucidate the mechanisms shaping the window of implantation and to investigate the potential markers based on these mechanisms are required. In addition, molecular testing of the endometrium at single-cell resolution should be an initial step toward developing clinically meaningful tests for the optimal window of implantation. As understanding of the optimal window of implantation continues to evolve, one can envision the future development of non-invasive, mechanism-based testing of the window of implantation.

The Role of Plasminogen Activator Inhibitor Type 1 (PAI-1) in Placenta-Mediated Pregnancy Complications: A Systematic Review

Plasminogen activator inhibitor type 1 (PAI-1) is a main inhibitor of fibrinolysis. The PAI-1 gene (SERPINE1) harbors genetic variants with the potential of modifying plasma levels of PAI-1. A delicate balance exists between the coagulation and fibrinolytic system, and changes in PAI-1 have been suggested to compromise establishment of a successful pregnancy. Therefore, this systematic review investigated the association between genetic variants and/or plasma levels of PAI-1 and placenta-mediated pregnancy complications. An extensive literature search was conducted in PubMed, Embase, and Web of Science on the 29^th of April 2021. All studies underwent quality rating according to The Study Quality Assessment Tools checklist provided by National Heart, Lung and Blood Institute. A total of 71 studies were included, among which 60 studies investigated PAI-1 genotypes and 11 studies measured PAI-1 plasma levels. In 32 out of 59 studies, no association was found between the PAI-1 4G/5G polymorphism (rs1799768) and placenta-mediated pregnancy complications, which was stated as no significant difference in the genotype distribution comparing women with and without placenta-mediated pregnancy complications or no significantly increased odds of placenta-mediated pregnancy complications carrying the 4G/4G or 4G/5G genotype. Eight out of 11 studies reported significantly higher PAI-1 plasma levels in preeclamptic women than in women without preeclampsia. In conclusion, no clear evidence indicates that PAI-1 polymorphisms are associated with placenta-mediated pregnancy complications, and the possible association between high PAI-1 plasma levels and preeclampsia needs further investigations. Thus, investigation of PAI-1 genotypes and PAI-1 plasma levels does not currently seem to have a place in daily clinical practice managing placenta-mediated pregnancy complications.

Prevalence and Multiplicity of Thrombophilia Genetic Polymorphisms of F V, MTHFR, F II, and PAI -I: A Cross-Sectional Study on a Healthy Jordanian Population

Background

FV, MTHFR, II, and PAI-I are the most common genes associated with thrombophilia genetic variants, which vary among different populations and ethnic groups. Little is known about the prevalence and multiplicity of these variants in Jordan. The aim of this study was to estimate the prevalence and multiplicity of the FV G1691A, FV H1299R, MTHFR 1298A>C, MTHFR 677C>T, II 20210G>A, and PAI-I 675 4G/5G variants among healthy Jordanians.

Methods

This cross-sectional study was conducted on randomly selected healthy Jordanian participants. Non-Jordanians and those with a history of arterial/venous thrombosis, atherosclerosis, or a history of recurrent abortions were excluded from the study. PCR was used to detect variants in DNA extracted from participants' blood samples.

Results

A total of 300 subjects were screened: 170 (56.7%) females with an average age of 27.78±9.32 years and 130 (43.3%) males with an average age of 29.88±8.55 years. Genetic variants (at least one) were found in 75% of the subjects (81.2% among females and 66.9% among men), while 64.7%, 52%, and 12% were found to have at least two, three, and four variants, respectively. Overall, 21%, 29%, 54.3%, 27.3%, 7.7%, and 66% of participants were found to have FV G1691A, FV H1299R, MTHFR 1298A>C, MTHFR 677C>T, II 20210G>A, and PAI-I 675 4G/5G gene variants, respectively.

Conclusion

Three-quarters of our population had at least one of the thrombophilia genetic variants, and most had more than one variant. The most common variants detected were associated with MTHFR, followed by PAI-I, FV, and then II. We observed that females had higher prevalence estimates than males. However, multiplicity among males was significantly higher than females. Our findings indicated noticeable differences in prevalence estimates compared with other populations.

Gestational Diabetes and Risk Assessment of Adverse Perinatal Outcomes and Newborns Early Motoric Development

Background and Objectives: The aim of this study was to analyze the presence of gestational diabetes mellitus (GDM) on maternal and fetal perinatal parameters, as well to evaluate the influence of GDM on neonatal early motoric development. Materials and Methods: In this prospective study, we evaluated 203 eligible participants that were admitted to obstetrics department for a labor. GDM was assessed by evaluation of maternal parameters, fetal parameters, as well its impact on infants early motoric development (Alberta Infant Motor Scale—AIMS). Results: Presence of GDM was significantly positively associated with: pre-pregnancy weight, obesity degree, weight at delivery, gestational weight gain (GWG), body mass index (BMI) at delivery, GWG and increased pre-pregnancy BMI, glucose levels in mother’s venous blood after the delivery, positive family history for cardiovascular disease, pregnancy-related hypertension, congenital thrombophilia, drug use in pregnancy, large for gestational age (LGA), mode of delivery (Cesarean section and instrumental delivery). Likewise, GDM association was detected for tested ultrasound parameters (biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), femoral length (FL)), length at birth, birth weight, newborn’s head circumference, newborn’s chest circumference, AIMS supination and pronation at three months, AIMS supination, pronation, sitting and standing at six months. Only Amniotic Fluid Index and AIMS supination at three months of infant’s age remained significantly associated in multivariate regression model. Conclusions: The presence of significant positive association of numerous tested parameters in our study on perinatal outcomes and early motoric development, points to the necessity of establishing appropriate clinical decision-making strategies for all pregnant woman at risk and emphasize the importance of providing adequate glycaemia control options and further regular follow ups during the pregnancy.

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.

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.

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.

Hemostasis-related gene polymorphisms and their epistatic relationship in women with idiopathic infertility

: A numerous factor can cause infertility, but around one of four reproductive failure cases remain unexplained and diagnosed as idiopathic infertility. In the past few decades, analysis of gene polymorphisms takes a significant place in pathogenesis of infertility. The aim of this study was to evaluate the possible role of hemostasis-related gene polymorphisms in unexplained infertility. The study includes 117 female patients with idiopathic infertility and 130 fertile women with at least one born child. Eight polymorphisms important for hemostasis (ITGB3 1565T>C, FV 1691G>A, FII 20210G>A, MTHFR 677C>T and 1298A>C, ATIII 786G>A, PAI-14G/5G and ACE I/D) were genotyped by real-time PCR system. The frequencies of alleles and genotypes of examined polymorphisms were analyzed in SPSS statistical program, whereas gene interactions were identified using the GMDR software. Examination of etiological factors has shown that family history is a significant factor in assessing individual risk for infertility. The alleles and genotypes frequency of FV 1691G>A and FII 20210G>A polymorphisms were statistically different between control and patient group leading to a greater risk for infertility. The analysis of epistatic relationship between examined hemostasis-related gene polymorphisms identified more complex high-risk genotypes associated with infertility. Our results suggest that positive family history could be important predictive factor for fertility problems, pointing to the potential hereditary basis of this condition. Polymorphisms FVL and FII prothrombin are independent risk factors for idiopathic infertility, whereas multilocus interactions approach should be taken into consideration for the future research.

The Genetic Variability of APOE in Different Human Populations and Its Implications for Longevity

Human longevity is a complex phenotype resulting from the combinations of context-dependent gene-environment interactions that require analysis as a dynamic process in a cohesive ecological and evolutionary framework. Genome-wide association (GWAS) and whole-genome sequencing (WGS) studies on centenarians pointed toward the inclusion of the apolipoprotein E (APOE) polymorphisms ε2 and ε4, as implicated in the attainment of extreme longevity, which refers to their effect in age-related Alzheimer's disease (AD) and cardiovascular disease (CVD). In this case, the available literature on APOE and its involvement in longevity is described according to an anthropological and population genetics perspective. This aims to highlight the evolutionary history of this gene, how its participation in several biological pathways relates to human longevity, and which evolutionary dynamics may have shaped the distribution of APOE haplotypes across the globe. Its potential adaptive role will be described along with implications for the study of longevity in different human groups. This review also presents an updated overview of the worldwide distribution of APOE alleles based on modern day data from public databases and ancient DNA samples retrieved from literature in the attempt to understand the spatial and temporal frame in which present-day patterns of APOE variation evolved.

Effect of multiple thrombophilic gene mutations on uterine artery blood flow in nonpregnant recurrent pregnancy loss patients: are we searching enough?

Objective: To investigate whether multiple thrombophilic mutations had a significant effect on uterine artery blood flow of nonpregnant recurrent pregnancy loss (RPL) patients.Materials and methods: Among 71 RPL patients, FV Leiden (FV), prothrombin G20210A (PTGM) and MTHFR mutations, deficiency of protein S, protein C and antithrombin III (AT3), association of Val34Leu polymorphism of the FXIII (FXIII), 4G/5G polymorphism of plasminogen activator inhibitor (PAI), -455-G/A polymorphism of β-fibrinogen (fibrinogen), and HPA-1 a/b L33P polymorphism of GPIIIa (GPIIIa) genes were investigated. Doppler flow measurements of RPL patients and healthy controls were performed at mid-luteal phase.Results: Twenty-two patients who had no thrombophilic gene mutations were grouped as unexplained RPL. Also, while 25 patients had multiple mutations, 24 patients had single mutation. In the multiple mutation RPL group, the most frequent mutations were PAI (22%), MTHFR C677T (20%), MTHFR A1298C (19%), and fibrinogen (11%). Only in the multiple mutation RPL group, mean PI and dominant PI values were significantly higher than the control group.Conclusions: Our data showed negative effects of multiple thrombophilic gene mutations on uterine artery blood flow and clarified the different effects of single and multiple thrombophilic factors on uterine artery vasculature. It is concluded that investigating more thrombophilic mutations could ameliorate prognostic factors of RPL and interactions to improve uterine artery blood flow could bring benefit to obstetric outcome.

Investigating Association of rs5918 Human Platelets Antigen 1 and rs1800790 Fibrinogen β Chain as Critical Players with Recurrent Pregnancy Loss

Thrombophilia gene variants have been shown to be associated with higher risk of recurrent pregnancy loss (RPL). Due to the role of human platelets antigen 1 (HPA-1) and fibrinogen β chain (FGB) as critical players in the coagulation process, their most important variants including rs5918 T > C and rs1800790 G > A were selected to be studied in women affected by RPL. Three milliliters of peripheral blood were drawn from 110 women with history of at least two consecutive spontaneous abortion and 110 healthy women controls. rs5918 T > C and rs1800790 G > A of HPA-1 and FGB genes, respectively, were selected to be analyzed through polymerase chain reaction-restriction fragment length polymorphism (PCR_RFLP) following DNA isolation using QIAamp DNA Blood Mini Kit. Heterozygote genotype (TC) of HPA-1 gene rs5918 polymorphism was significantly associated with risk of RPL (p-value = 0.02). Although, rs1800790 G > A of FGB gene was not associated with RPL, its combination with rs5918 polymorphism was associated with increased risk of RPL. Owing to the critical roles of FGB and HPA-1 genes in coagulation, and thrombosis and several confinements on the meaningful association between the combination of those polymorphism with risk of RPL, including them in the thrombophilia panel may increase detection rate of hereditary thrombophilia patients. However, further studies with larger sample sizes are required to shed light on the exact role of the studied gene polymorphism, especially rs1800790 G > A of FGB gene variant in pathogenesis of RPL.

Impact of maternal methylenetetrahydrofolate reductase C677T polymorphism on intervillous and decidual pathology with pregnancy loss

AIM

The association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and intervillous and decidual pathology in patients with pregnancy loss was investigated.

METHODS

We performed a cross-sectional study on 243 patients presenting with pregnancy loss for the degree of intervillous fibrin and thrombosis (IT), and decidual fibrin and thrombosis (DT) and determined their MTHFR C677T genotypes. Overall differences in age, body mass index (BMI), gravidity, parity, number of pregnancy losses and gestational period when the pathologic samples were obtained, also were determined.

RESULTS

There were no significant differences in age, BMI, gravidity, parity, number of pregnancy losses and gestational period, relative to MTHFR C677T genotype (TT vs CT vs CC). There were significantly more T allele carriers and TT genotype patients among patients with severe IT (odds ratio [OR] 1.653, P = 0.033 and OR 2.246, P = 0.032, respectively) and those with severe IT and decidual thrombosis (OR 2.602, P = 0.012 and OR 3.375, P = 0.035, respectively). The CC genotype was protective against the four studied pathologic grades.

CONCLUSION

To our knowledge, this is the first study showing that the MTHFR C677T TT genotype and T allele are associated with severe intervillous and decidual pathologies in patients with pregnancy loss. Differences in pathologic grades of MTHFR C677T TT genotype could support the hypothesis that further periconceptional treatment for pregnancy loss could be customized depending on single nucleotide polymorphisms.

Association between thrombophilia gene polymorphisms and recurrent pregnancy loss risk in the Iranian population

Miscarriage is the most common complication in pregnancy. Considering the importance of the problem thrombophilia in pregnant women and its association with recurrent pregnancy loss (RPL), analysis of polymorphisms of genes involved in thrombophilia can be useful. We investigated the frequency and association between ten polymorphisms of seven thrombophilia genes and RPL in an Iranian population. This case-control study was conducted on 200 women with recurrent pregnancy loss and also on 200 women with at least one successful pregnancy as the control group. Using PCR-RFLP, DNA from samples were analyzed for carrying A5279G, A4070G, and FV Leiden of factor V; FXIII (Val34Leu); FII (A20210G); BF (-455 G⁄A); ITGB3 (1565T⁄C); 677C/T and 1298A/C of MTHFR; and PAI-1 (-675 I/D, 5G/4G) polymorphisms. The BF(-455 G⁄A), MTHFR (677 C⁄T, 1298A⁄ C), PAI-1 (-675 I/D,4G⁄ 5G), FV Leiden, FV (A5279G), FXIII (Val34Leu) polymorphisms, which had shown positive relation, and ITGB3 1565T⁄C were the polymorphisms with negative relation to RPL. But in this study it is indicated that there is no significant association between FII (A20210G) and FV (A4070G) polymorphism and RPL. All the data acquired from the RPL patients in this experiment illustrate the importance of screening thrombophilia. Nevertheless, more studies on large-scale populations may be needed to identify novel genetic variants.

ABBREVIATIONS

ASRM: American Society of Reproductive Medicine; HHCY: hyperhomocysteinemia; MTHFR: methylenetetrahydrofolate reductase; PCR: polymerase chain reaction; PAGE: poly-acrylamide gel electrophoresis; RPL: recurrent pregnancy loss.

Polymorphisms of F2, PROC, PROZ, and F13A1 Genes are Associated With Recurrent Spontaneous Abortion in Chinese Han Women

Mutations of hemostasis/coagulation-related genes have been speculated to cause recurrent spontaneous abortion (RSA). This study investigated the genetic association between the polymorphisms of factor V (F5), factor II (F2), antithrombin (SERPINC1), protein C (PROC), protein S (PROS1), protein Z (PROZ), factor XIII (F13A1), and carboxypeptidase B2 (CPB2) genes and RSA. The 426 patients with RSA and 444 controls were recruited in this study, and single-nucleotide polymorphisms (SNPs) were analyzed by using SNPscan technology. Genotype and allele frequencies of rs3136520 in F2, rs3024731 in PROZ, and rs1050782 in F13A1 showed statistically significant differences between the 2 groups. TT genotype of rs3136520 (P = .031, odds ratio [OR] = 0.986, 95% confidence interval [CI] = 0.976-0.997) and AA genotype of rs2069906 in PROC (P = .021, OR = 0.114, 95% CI = 0.014-0.902) in their recessive models and AG + GG variants of rs1050782 (P = .007, OR = 0.681, 95% CI = 0.516-0.899) in the dominant model might be associated with the reduced risk of RSA. AT + TT variants of rs3024731 (P = .010, OR = 1.479, 95% CI = 1.098-1.994) may increase disease susceptibility in dominant model. Haplotype analysis of rs3024731 and rs3024735 in PROZ displayed that the AA and TG haplotype were inclined to decrease and increase the risk of RSA, respectively. These results suggested that rs3136520, rs2069906, rs3024731, and rs1050782 may have a significant association with the genetic susceptibility of RSA in Chinese Han women.

Methylenetetrahydrofolate Reductase Polymorphisms and Risk of Recurrent Pregnancy Loss: a Case-Control Study

The balance between coagulation and fibrinolysis is an essential part in early pregnancy. Mutations in methylenetetrahydrofolate reductase (MTHFR) gene lead to decreased activity of the enzyme and hyperhomocysteinemia, which then induces platelet aggregation by promoting endothelial oxidative damage, possibly resulting in adverse effect on maintenance of pregnancy. We investigated the role of MTHFR single nucleotide polymorphisms (SNPs), C677T and A1298C, in Korean patients with recurrent pregnancy loss (RPL). We conducted a prospective case-control study in the Korean population. Subjects included 302 women with 2 or more consecutive, unexplained, spontaneous miscarriages before 20 weeks of gestation and 315 control women without a history of recurrent miscarriages. The genotyping for C677T and A1298C polymorphisms was performed using the TaqMan assay. Continuous variables were compared using Student's t-test, and χ² test was used to evaluate differences in the genotype distributions between the RPL and the controls. The genotype distribution of both polymorphisms in the RPL group did not differ from those of the controls. For further analysis, if RPL patients were divided according to the numbers of pregnancy losses (≥ 2 and ≥ 3) neither group was significantly different compared with controls. MTHFR gene C677T and A1298C polymorphisms are not associated with idiopathic RPL in Korean women, suggesting that those may not be susceptible allelic variants or be deficient to cause RPL.

Thrombophilic gene polymorphisms and recurrent pregnancy loss in Greek women

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Genetics of suspected thrombophilia in Serbian females with infertility, including three cases, homozygous for FII 20210A or FV 1691A mutations

Reproductive failure (recurrent foetal loss, unexplained infertility and IVF implantation failure) may be, in a number of cases, explained by thrombophilia, either acquired or inherited. Several genes contribute to thrombophilia, some with major effect (Factor V, Factor II), and some with minor effect (MTHFR, PAI-1, ATIII, etc.). The aim of this study was to estimate frequency of thrombophilia-associated genotypes (FII20210G > A, FV1691G > A, MTHFR677C > T and PAI-1 -675 4G/5G) in a group of 1631 Serbian women experiencing reproductive failure, and compare it with a healthy, female control group. Our results showed marginally significant (p = 0.050) differences in allele frequencies between patients and controls for the FV1691 mutations. For the FII20210G > A, although the statistical significance was not achieved (p = 0.076), we found higher frequency of variant allele in patients compared to controls (1.87% vs. 0.38%, respectively) which may point to a possible role of this polymorphism in thrombotic events. For the MTHFR677C > T and PAI-1 -675 4G/5G, we found no difference in distributions of genotype or allele frequencies between these two groups (p > 0.05). For three subjects with very rare genotypes (two patients homozygous for FV1691G > A and one patient homozygous for FII20210G > A) we performed additional biochemical analyses for haemostasis, as well as genotyping of two polymorphisms (MTHFR1298A > C and ATIII786G > A).

Toward optimal set of single nucleotide polymorphism investigation before IVF

BACKGROUND

At present, the patient preparation for IVF needs to undergo a series of planned tests, including the genotyping of single nucleotide polymorphism (SNP) alleles of some genes. In former USSR countries, such investigation was not included in overwhelming majority of health insurance programs and paid by patient. In common, there are prerequisites to the study of more than 50 polymorphisms. An important faced task is to determine the optimal panel for SNP genotyping in terms of price/number of SNP.

MATERIALS AND METHODS

During 2009-2015 in the University Hospital of St. Petersburg State University, blood samples were analyzed from 550 women with different reproductive system disorders preparing for IVF and 46 healthy women in control group. In total, 28 SNP were analyzed in the genes of thrombophilia factors, folic acid cycle, detoxification system, and the renin-angiotensin system. The method used was real-time PCR.

RESULTS

A significant increase in the frequency of pathological alleles of some polymorphisms in patients with habitual failure of IVF was shown, compared with the control group. As a result, two options defined panels for optimal typing SNP before IVF were composed. Standard panel includes 8 SNP, 5 in thromborhilic factors, and 3 in folic acid cycle genes. They are 20210 G > A of FII gene, R506Q G > A of FV gene (mutation Leiden), -675 5G > 4G of PAI-I gene, L33P T > C of ITGB3 gene, -455 G > A of FGB gene, 667 C > T of MTHFR gene, 2756 A > G of MTR gene, and 66 A > G of MTRR gene. Extended panel of 15 SNP also includes 807 C > T of ITGA2 gene, T154M C > T of GP1BA gene, second polymorphism 1298 A > C in MTHFR gene, polymorphisms of the renin-angiotensin gene AGT M235T T > C and -1166 A > C of AGTR1 gene, polymorphisms I105V A > G and A114V C > T of detoxification system gene GSTP.

CONCLUSION

The results of SNP genotyping can be adjusted for treatment tactics and IVF, and also medical support getting pregnant. The success rate of IVF is increased as the result, especially in the group with the usual failure of IVF.

Interaction of apolipoprotein E gene polymorphisms on miscarriage risk in black and white American women

OBJECTIVE

To evaluate whether [1] apolipoprotein E (APOE) polymorphisms can differentially regulate miscarriage risk and [2] whether this genotype effect could also be modulated by the race within populations.

DESIGN

Data were derived from the Coronary Artery Risk Development in Young Adults (CARDIA), a longitudinal study with black and white participants from four U.S.

SETTING

Not applicable.

PATIENT(S)

Women without miscarriages (controls) and women who miscarried at least once (cases).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

A group of women (n = 1,372) successfully followed for 25 years and with their APOE alleles identified were analyzed for miscarriage risk throughout their reproductive life. Additionally, a larger longitudinal analysis encompassing all the participants who had their APOE characterized (n = 2,140) was also performed for the association between APOE and miscarriage risk.

RESULT(S)

In white women followed up for 25 years, the odds ratio for miscarriage associated with APOE*2 allele presence was 1.61 (95% confidence interval, 1.04-2.50) compared with APOE*33 carriers. This was a race-dependent phenomenon as no associations between APOE alleles and miscarriage was observed in black women. Likewise, Cox regression analysis showed that cumulative miscarriage risk in white women was 37.2% in the APOE*2 carriers compared with 27.8% and 24.8% in APOE*33 and APOE*4 carriers, respectively. With APOE*33 as the reference, the age-adjusted hazard ratio associated with carrying the APOE*2 allele was 1.47 (95 confidence interval, 1.06-2.05).

CONCLUSION(S)

This variable miscarriage risk, produced by an interaction between genotype and race, may reconcile, at least partially, the conflicting reports of the association of APOE and miscarriage risk.

Insertion/deletion polymorphism in intron 16 of ACE gene in idiopathic recurrent spontaneous abortion: case-control study, systematic review and meta-analysis

The insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin I-converting enzyme gene (ACE) has been extensively studied as a predisposing factor for idiopathic recurrent spontaneous abortion (IRSA). A case-control study including 149 women with ≥3 spontaneous abortions and 149 controls was performed to test the association of ACE I/D polymorphism with IRSA. A systematic review was conducted of previous case-control studies, with strict selection criteria for meta-analyses. We also aimed to evaluate the potential differences in summary estimates between studies defining IRSA as ≥2 and ≥3 spontaneous abortions. Genotyping was performed by PCR, and systematic review conducted using PubMed and Scopus. There was no association of the polymorphism with IRSA in Slovenian women. Sixteen case-control studies, showing substantial differences regarding IRSA definition and selection criteria for women were identified. Meta-analysis was performed and included four studies defining IRSA as ≥2 spontaneous abortions and the current study, which defined IRSA as ≥3 spontaneous abortions. Based on random effects model, meta-analysis conducted on 1192 patients and 736 controls showed no association with IRSA under dominant(DD+IDvsII) and recessive(DDvsID+II) genetic models. Well-designed studies are needed to evaluate the role of ACE I/D polymorphism in IRSA defined as ≥3 spontaneous abortions.

Factor XIIIA-V34L and factor XIIIB-H95R in venous thromboembolism in central Iran: protective and neutral

Polymorphisms of coagulation factor XIII, an A2B2 tetramer, have been reported in correlation with venous and arterial thrombotic events. As there were limited data on these polymorphisms from Iranian population, we studied the correlation of factor XIIIA-Val34Leu and factor XIIIB-His95Arg with venous thromboembolism (VTE) in central Iran. Venous blood was collected from 102 unrelated VTE patients, diagnosed as pulmonary embolism, deep vein thrombosis (DVT), and pulmonary embolism/DVT and 165 healthy persons as control group. Genotyping was performed from DNA for FXIIIA-V34L and FXIIIB-H95R by polymerase chain reaction-restriction fragment length polymorphism and data were analyzed using Statistical Package for the Social Services software. There was no difference in age among the three groups of patients and between male and female participants. 41.02% of patients versus 42.04% of controls were carriers of FXIIIA-V34L as homozygous or heterozygous. Homozygosity of 34LL was significantly lower in patients compared with control participants (OR: 0.107, 95% CI: 0.14-0.83, P = 0.01) with only one homozygous in patients compared with 14 in the control group. Factor XIIIB-H95R was observed in 26.5% of patients versus 17.6% of control participants with no significant difference. There was no significant difference between patients and control group in homozygosity. Our findings on the frequency of FXIIIA-V34L is compatible with Caucasians. The significantly higher existence of homozygous 34LL in control participants is comparable with those who found it as protective against VTE. It may help to recognize risk factors or may contribute to prophylaxis in family members. We found FXIIIB-H95R polymorphism neutral. As there are different ethnicities in Iran, it may be beneficial to study other populations.

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.

Apolipoprotein E genotyping in women with recurrent pregnancy loss: an in silico and experimental hybrid study

The role of apolipoprotein E gene polymorphisms in the pathogenesis of recurrent pregnancy loss remains controversial. Therefore, our objective was to investigate the association between recurrent pregnancy loss and apolipoprotein E gene polymorphisms among northwest Iranian women, and also to predict the impact of these nonsynonymous single nucleotide polymorphisms on structure and function of apolipoprotein E protein. The subjects of our current study consisted of 100 women that have had two or more consecutive idiopathic first trimester miscarriages, and one hundred healthy women from the same geographical areas were used as a control group. After DNA extraction, we used a polymerase chain reaction-restriction fragment length polymorphism to genotype of the apolipoprotein E gene. In addition, we predicted the possible effects of amino acid substitutions at codons 112 and/or 158 on the structure and function of apolipoprotein E protein using Polymorphism Phenotyping online software v2. Our results showed that the rate of apolipoprotein E ε4 carriers and the frequency of the ε4 allele in the case group were statistically and significantly higher than those in the control group (P<0.05). Therefore, our data support the association of the Apo ε4 allele with RPL; however, in silico analysis predicted that the amino acid substitution at residue 112 (Apo ε4 allele) is a benign mutation. Accordingly, further studies are required to elucidate the mechanism(s) underlying the link between RPL pathogenesis and the Apo ε4 allele.

Risk for early pregnancy loss by factor XIII Val34Leu: the impact of fibrinogen concentration

BACKGROUND

We have already described a significantly elevated overall risk for recurrent pregnancy loss (RPL) in women carrying the coagulation factor XIII (FXIII) Val34Leu and/or the plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism assuming that these polymorphisms contribute synergistically to RPL because of impaired hypofibrinolysis. Recent studies on FXIII indicate that the impact of the FXIII 34Leu genotype on fibrin structure and fibrinolysis is affected by fibrinogen concentration. Therefore, we reinvestigated the association between fibrinogen concentrations and FXIII Val34Leu with early RPL.

MATERIALS AND METHODS

In this case-control study, we enrolled 49 women with a history of two consecutive or three to six nonconsecutive pregnancy losses between the 8th and 12th week of gestation and 48 healthy controls. The risk for RPL in carriers of FXIII 34Leu at fibrinogen levels above or below the median and first tertile of controls was evaluated.

RESULTS

In carriers of the 34Leu allele, fibrinogen levels below the median (i.e., ≤ 300 mg/dl) and the first tertile (i.e., ≤ 284 mg/dl) of controls were associated with an increased risk for RPL [(2.9 (1.1-7.7), 3.9(1.0-15.0)].

CONCLUSIONS

The FXIII Val34Leu polymorphism may be associated with the development of early RPL in association with fibrinogen concentrations. At fibrinogen levels in the low normal range, FXIII 34Leu may modify fibrin structure toward an increased resistance to fibrinolysis.

Paternal factor V Leiden and recurrent pregnancy loss: a new concept behind fetal genetics?

BACKGROUND

In up to 50% of couples affected by recurrent pregnancy loss, no identifiable cause is established. Fetal and maternal factors may be equally important in the establishment and maintenance of the placental/maternal arteriovenous anastomoses. Therefore,the inheritance of thrombophilia-related genes may be an important factor in the pathophysiology of recurrent pregnancy loss. Most of the research on recurrent pregnancy loss and thrombophilia has focused on maternal factors, but little is known about the paternal contribution.

OBJECTIVES

On that basis, we studied the association between inherited paternal thrombophilias and recurrent pregnancy loss in a narrowly selective group of 42 Argentine males from couples that presented without any known risk factors for recurrent pregnancy loss.

PATIENTS AND METHODS

The genotypic distributions of factor (F) V Leiden and prothrombin G20210A among cases were compared with those from a reference group composed of 200 Argentine men.

RESULTS

We found a significant difference in the distribution of FV Leiden between both groups (16.7% vs. 3.0%), but no difference was found in the distribution of prothrombin G20210A (2.4% vs.2.0%). Those couples with paternal FV Leiden carriage would be six times more likely to experience recurrent pregnancy loss despite no other apparent cause (OR = 6.47; 95% CI, 2.06–20.39).

CONCLUSION

We found evidence of an association between the paternal carriage of FV Leiden and the predisposition to recurrent pregnancy loss, thereby supporting the hypothesis that genetic contributions from both parents are essential factors in the development of this obstetric disorder.

Evaluation of chromosomal abnormalities and common trombophilic mutations in cases with recurrent miscarriage

BACKGROUND

Recurrent miscarriage (RM) is a frequent obstetric problem. Its' pathophysiology is poorly understood. Infections, genetic, endocrine, anatomic and immunologic problems have been suggested as causes for RM.

OBJECTIVE

To evaluate the frequency of chromosomal abnormalities and 3 common thrombophilic mutations in couples with RM.

METHODS

A retrospective data collection was performed for the results of the cytogenetic analysis of the couples and Methylenetetrahydrofolate Reductase (MTHFR) C677T, Factor V Leiden (FVL) G1691A and Prothrombin (PTm) G20210A mutations of the mother in 142 couples suffering from RM.

RESULTS

Prevalence of FVL, MTHFR, and PTm gene mutations were similar between cases shaving 2 or ≥3 abortions (P=0.528; P=0.233; P=0.375). In patients with FVL, MTHFR and PTm gene mutations, the OR's of having ≥3 abortions when compared to having 2 abortions were 1.515 (95% CI: 0.414-5.552), 0.573 (95% CI: 0.228-1.441), and 2.848 (95% CI: 0.355-22.871). All cases with PTm mutation had ≥3 abortions and all abortions occurred between 6-8 gestational weeks.

CONCLUSION

Chromosomal abnormalities and thrombophilic mutations (especially PTm) seem to have an important role in RM. Additional larger studies involving investigation of more genes that may have a role in pregnancy are needed to assess this association.

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.

Apolipoprotein E (Apo E) gene polymorphisms and recurrent pregnancy loss: a meta-analysis

BACKGROUND

Recently, a relationship between recurrent pregnancy loss (RPL) and Apolipoprotein E (Apo E) gene polymorphisms has been proposed. In order to investigate the real association between Apo E polymorphisms and RPL, our meta-analysis was carried out.

METHODS

We estimated the association with RPL risk under dominant and recessive models, in combination with the OR and RR with a 95% confidence interval (CI), which was used to assess the association between RPL and Apo E polymorphisms.

RESULTS

According to our criterion, there were 6 studies included. The dominant model used the E4/E3 group and the OR was 1.919 (95 %CI: 1.016-3.625, I(2) = 53.8%), the RR was 1.308 (95%Cl: 1.071-1.598) suggesting that carriers of the E4 allele would have a higher risk of causing spontaneous miscarriages. In addition, the OR was 0.727 (95%CI: 0.566-0.932, I(2) = 0.0%) and RR was 0.923 (95%CI: 0.867-0.982) in a fixed model for E3/E3 homozygotes versus other genotypes, suggesting that the Apo E3 polymorphism could be a protective factor. The OR was 1.365 (95% CI: 1.029-1.811, I(2) = 0 .0%) in a fixed model comparing the E2 allele with the E3 allele, suggesting that Apo E2 polymorphisms may contribute to RPL as a risk factor. Furthermore, after conducting sensitivity analysis in the E4/E3 group, the results showed this to be consistent and the OR was 2.249 (95%CI: 1.474-3.431).

CONCLUSIONS

There is a close association between RPL and Apo E gene polymorphisms. For RPL, the Apo E4 polymorphism could be a risk factor, the Apo E3 polymorphism may be a protective factor and the Apo E2 polymorphism may be another potential risk factor.

Significant association between angiotensin-converting enzyme gene insertion/deletion polymorphism and risk of recurrent miscarriage: a systematic review and meta-analysis

BACKGROUND

Many studies have investigated the association between angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and risk of recurrent miscarriage, but the impact is unclear due to inconsistencies among those studies. This study aimed to quantify the strength of the association between ACE I/D polymorphism and recurrent miscarriage risk by performing a systematic review and meta-analysis.

DESIGN AND METHODS

We searched PubMed, Embase, Web of Science, and Wanfang Medicine databases for eligible articles relating the association between ACE I/D polymorphism and risk of recurrent miscarriage in humans. We estimated the summary odds ratios (ORs) with their 95% confidence intervals (95% CIs) to assess the association.

RESULTS

Eleven studies with a total of 3357 individuals were included in this meta-analysis. Compared to the ACE II genotype, DD and ID were both associated with increased risk of recurrent miscarriage (OR DD versus II=1.81, 95% CI 1.23-2.66, P=0.003; OR ID versus II=1.50, 95% CI 1.25-1.80, P<0.001). Sensitivity analyses further confirmed the association above. No evidence of publication bias was observed.

CONCLUSION

Meta-analyses of available data show a significant association between ACE I/D polymorphism and recurrent miscarriage risk, and the ACE polymorphic D allele contributes to increased risk of recurrent miscarriage.

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.

Polymorphisms in MTHFR, MTHFD, and PAI-1 and recurrent miscarriage among North Indian women

PURPOSE

The aim of this study was to investigate the association between MTHFR C677T, A1298C, MTHFD G1958A and plasminogen activator inhibitor type 1 (PAI-1) 4G/5G polymorphism among first trimester recurrent miscarriages.

MATERIALS AND METHODS

DNA was extracted from peripheral blood samples from 200 patients and 300 controls. Polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP) and sequencing were used to identify the polymorphisms. We have analyzed the frequencies, odds ratio, Hardy-Weinberg equilibrium.

RESULTS

MTHFR C677T, A1298C, and MTHFD G1958A variant alleles were found to be significantly more prevalent in patients than control. However, variant genotype of MTHFR C677T (OR = 2.54; 95 % CI = 1.23-5.24; p value = 0.014), 1298C (OR = 2.23; 95 % CI = 1.09-4.52; p value = 0.028), and MTHFD-1958 showed significant association with pregnancy loss (OR = 2.36; 95 % CI = 1.39-4.02; p value = 0.002). Both MTHFR 677 and MTHFD 1958 showed susceptible effect under recessive model of inheritance. PAI-1 mutations showed no significance.

CONCLUSION

We observed significant susceptible effects of MTHFR C677T, A1298C, and MTHFD G1958A among RM cases. Our data points toward the multifactorial nature of the recurrent miscarriage as relative contribution of variant genotype of MTHFR C677T is only twofold and further decreased to only onefold, and MTHFD-1958 lost its significance upon meta-analysis.

Study on potential role of apolipoprotein E in recurrent pregnancy loss

The role of apolipoprotein E (Apo E) gene polymorphisms in the etiology of recurrent pregnancy loss (RPL) is not clearly understood. We evaluated this polymorphism in unexplained pregnancy losses in a group of Turkish women. In our prospective case-control study, 45 well-characterized RPL cases were examined for their Apo E genotypes, based on restriction fragment length polymorphism analysis of polymerase chain reaction (PCR)-amplified fragments. The observed genotypes were compared with those obtained from equal number matched controls. We observed similar Apo E genotypes and E2, E3 and E4 allele frequency distribution among RPL patients and controls. The allele frequencies obtained in patients and controls, respectively, were as follows: E2=8 (9%) and 12 (13.4%) (P=0.342), E3=66 (73.3%) and 60 (66.6%) (P=0.328) and E4=16 (17.7%) and 18 (20%) (P=0.703). Our data did not support the association of Apo E gene polymorphisms with RPL as reported by previous studies. We endorse adequate characterization of RPL cases and adequate sample size prior to addressing such studies.

Plasminogen activator inhibitor 1 4G/5G and -844G/A variants in idiopathic recurrent pregnancy loss

PROBLEM

Plasminogen activator inhibitor type 1 (PAI-1) regulates fibrinolysis, and the common promoter region variants -675G/A (4G/5G) and -844G/A are associated with increased thrombotic risk. Despite evidence linking altered fibrinolysis with adverse pregnancy events, including idiopathic recurrent pregnancy loss (RPL), the contribution of PAI-1 variants to RPL risk remains controversial. We investigated the association between the PAI-1 -844G/A and 4G/5G (-675G/A) variants with altered risk of RPL.

METHOD OF STUDY

This was a case-control study involving 304 women with confirmed RPL and 371 age- and ethnically matched control women. PAI-1 genotyping was performed by PCR single-specific primer -675 (G/A) and real-time PCR (-844G/A) analysis.

RESULTS

Minor allele frequency (MAF) of 4G/5G (P < 0.001), but not -844G/A (P = 0.507), was higher in RPL cases. PAI-1 4G/5G single-nucleotide polymorphism (SNP) was significantly associated with RPL under additive, dominant, and recessive genetic models; no association of -844G/A with RPL was seen irrespective of the genetic model tested. Taking common -844G/5G haplotype as reference (OR = 1.00), multivariate analysis confirmed the association of 4G-containing -844A/4G (P < 0.001) and -844G/4G (P = 0.011) haplotypes with increased RPL risk.

CONCLUSION

4G/5G, but not -844G/A, PAI-1 variant is associated with an increased risk of RPL.

Recurrent pregnancy loss, plasminogen activator inhibitor-1 (-675) 4G/5G polymorphism and antiphospholipid antibodies in Czech women

PROBLEM

This study compares the frequencies of plasminogen activator inhibitor-1 (-675) 4G/5G polymorphism and its relationship with eight antiphospholipid antibodies (aPLs) in serum of 157 patients with repeated pregnancy loss (RPL).

METHOD OF STUDY

PAI-1 (-675) 4G/5G polymorphism was determined using standard PCR-RFLP method. Enzyme-linked immunosorbent assay was used for the detection of aPLs against ph-serine, ph-ethanolamine, ph-inositol, ph-DL-glycerol, phosphatidic acid, annexin V, cardiolipin, and beta2-GPI. Allelic frequency and distribution of genotypes were calculated. The prevalence of the risk conferring 4G allele and 4G/4G homozygous genotype in patients and controls was compared, and the correlation between aPLs positivity and PAI-1 4G/4G genotype was tested by chi-square test.

RESULTS

Statistically highly significant correlation between RPL and PAI-1 (-675) 4G/4G genotype was found. No correlation between PAI-1 (-675) 4G/5G polymorphism and the presence of antiphospholipid antibodies in RPL patients was observed.

CONCLUSIONS

PAI-1 (-675) 4G/4G homozygous genotype increases the risk of RPL independently from the aPLs positivity.

Positive association of Apolipoprotein E4 polymorphism with recurrent pregnancy loss in Iranian patients

PROBLEM

Numerous lines of evidence implicate Apolipoprotein E (Apo E) in lipid metabolism during pregnancy. Hence, a role for its polymorphism has been envisaged in recurrent pregnancy loss (RPL) considering major structural and functional differences between different Apo E genotypes.

METHOD OF STUDY

A case control study of 81 women with two or more pregnancy losses that did not have any other known risk factors including anatomic anomalies of the reproductive system, infections, immunologic factors, hormonal imbalances, chromosomal abnormalities and environmental factors was carried out. The control group consisted of 81 women with at least two healthy children and no RPL in their reproductive history. DNA was extracted from the peripheral blood following written consent and Apo E genotyping was carried out by amplifying exon 4 of the gene and subjecting it to digestion by HhaI restriction enzyme.

RESULTS

Genotyping was concluded by analyzing different fragment sizes produced, which resulted in finding significantly higher frequency of combined E3/E4 and E4/E4 genotypes in the patients (about 20 %) compared to the normal controls (2.4 %). The genotypes were confirmed by DNA sequencing.

CONCLUSION

Allelic frequency for E4 was 13.5 % in the patients and only 1 % in the non-RPL group. Our findings confirm and are in line with a number of similar studies carried out on other populations. Therefore, Apo E4 polymorphism seems to be contributing to the thrombophilic risk factors as a background to RPL.

Methylenetetrahydrofolate Reductase C677T and A1298C Mutations in Women with Recurrent Spontaneous Abortions in the Northwest of Iran

Introduction. Recurrent spontaneous abortion (RSA) is a significant obstetrical complication that may occur during pregnancy. Various studies in recent years have indicated that two common mutations (C677T and A1298C) of the methylenetetrahydrofolate reductase (MTHFR) gene are risk factor for RSA. This study was carried out to determine the influence of (C677T and A1298C) of the methylenetetrahydrofolate reductase (MTHFR) gene mutations with RSA. Materials and Methods. A total of 139 women were included in this study: 89 women with two or more consecutive miscarriages and 50 healthy controls. Total genomic DNA was isolated from blood leukocytes. To determine the frequency of the two common C677T and A1298C MTHFR gene mutations in the patients and controls, we used two methods, amplification refractory mutation system-PCR and PCR-restriction fragment length polymorphism. Results. There is no significant difference in the prevalence of 677T/T genotype among women with RSA and healthy controls (P = 0.285). Also no statistically significant difference in the frequency of A1298C MTHFR gene mutation was detected between the two groups (P = 0.175 ). Conclusion. In conclusion, the results indicate that the Amplification Refractory Mutation System-PCR method was in complete concordance with the results obtained by standard PCR-restriction fragment length polymorphism method. The results also show no significant difference in MTHFR C677T/A1298C genotype distribution among the two groups; therefore, further studies on larger population and other genetic variants to better understand the pathobiology of RSA are needed.

Angiotensin-converting enzyme insertion/deletion (I/D) polymorphisms and recurrent pregnancy loss: a meta-analysis

BACKGROUND

Recurrent pregnancy loss (RPL) had said to be related to the angiotensin converting enzyme insertion/deletion polymorphisms (ACE I/D) gene polymorphisms. But the conclusions were controversial. This meta-analysis was conducted to investigate the real association in ACE I/D polymorphisms and RPL firstly.

METHODS

Combine Pubmed Embase and HuGENet database in data analysis for this meta-analysis from October 2000 to November 2011. The metagen system was used to select the models and effects. Odds ratio (OR) with 95% confidence interval (CI) was used to assess the strength of this association.

RESULTS

9 studies from six countries with 1264 RPL and 845 controls were included according to our criterion. Following the metagen system, we used the dominant model with random effects. The summary OR =1.61 (95% CI: 1.10-2.36, I (2) = 59.0%), which suggested the ACE D allele might increase the RPL risk in Asia (OR=1.97, 95% CI: 1.31-2.98, I (2) = 44.4%), among Asians (OR=1.69, 95% CI: 1.06-2.36, I (2) =32.7%). In additional, after conducting sensitivity analysis, the results had no differences except for Caucasian subgroup reached to the significance (OR=2.059, 95% CI: 1.455-2.914), so we couldn't ignore the relationship between the polymorphisms of ACE D/I gene and Caucasians yet. There seemed no publication bias in our eligible studies with Begg's test (P = 0.867).

CONCLUSIONS

Results in this meta-analysis presented the positive function of the ACE I/D polymorphism in increasing the RPL risk. Furfure prospective studies were needed to confirm the precise relationship between the ACE I/D and RPL.