The 4G/4G polymorphism of the hypofibrinolytic plasminogen activator inhibitor type 1 gene: an independent risk factor for serious pregnancy complications

Association of Polymorphisms in Plasminogen Activator Inhibitor-1 (PAI-1), Tissue Plasminogen Activator (tPA), and Renin (REN) with Recurrent Pregnancy Loss in Korean Women

Recurrent pregnancy loss (RPL) is defined as two or more consecutive pregnancy losses prior to 20 weeks of gestational age. Various factors, including immune dysfunction, endocrine disorders, coagulation abnormality, and genetic disorders influence RPL. In particular, plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA), and renin (REN) have important roles in the thrombotic and thrombolytic systems, and abnormal expression of these genes have a reported negative correlation with pregnancy maintenance. Moreover, some polymorphisms of the three genes are related to expression levels and thrombotic disorder. Therefore, we investigated whether polymorphisms of PAI-1, tPA, and REN are linked to RPL. Genotyping of the six polymorphisms (PAI-1 rs11178, rs1050955, tPA rs4646972, rs2020918, REN rs1464816, and rs5707) was performed using polymerase chain reaction (PCR)-restriction fragment length polymorphism and associations of the polymorphisms with RPL were evaluated by statistical analysis. The polymorphism PAI-1 rs1050955 GA+AA was associated with decreased RPL risk (AOR, 0.528; 95% CI 0.356–0.781; p = 0.001) as was the REN 10795 rs5707 GG genotype (AOR, 0.487; 95% CI 0.301–0.787; p = 0.003). In contrast, the tPA rs4646972 II genotype correlated with increased RPL risk (AOR, 1.606; 95% CI, 1.047–2.463; p = 0.030). This study provides evidence that tPA Alu rs4646972 may contribute to the risk of idiopathic RPL, but PAI-1 12068 rs1050955 and REN 10795 rs5707 are associated with a decreased risk of RPL. Therefore, these alleles may be useful as biomarkers to evaluate the risk of RPL.

Involvement of single nucleotide polymorphisms in ovarian poor response

PURPOSE

Unpredictability in acquiring an adequate number of high-quality oocytes following ovarian stimulation is one of the major complications in controlled ovarian hyperstimulation (COH). Genetic predispositions of variations could alter the immunological profiles and consequently be implicated in the variability of ovarian response to the stimulation.

DESIGN

Uncovering the influence of variations in AMHR2, LHCGR, MTHFR, PGR, and SERPINE1 genes with ovarian response to gonadotrophin stimulation in COH of infertile women.

METHODS

Blood samples of the women with a good ovarian response (GOR) or with a poor ovarian response (POR) were collected. Genomic DNA was extracted, and gene variations were genotyped by TaqMan SNP Genotyping Assays using primer-probe sets or real-time PCR Kit.

RESULTS

Except for PGR (rs10895068), allele distributions demonstrate that the majority of POR patients carried minor alleles of AMHR2 (rs2002555, G-allele), LHCGR (rs2293275, G-allele), MTHFR (rs1801131, C-allele, and rs1801133, T-allele), and SERPINE1 (rs1799889, 4G allele) genes compared to the GOR. Similarly, genotypes with a minor allele in AMHR2, LHCGR, MTHFR, and SERPINE1 genes had a higher prevalence among POR patients with the polymorphic genotypes. However, further genotype stratification indicated that the minor alleles of these genes are not associated with poor response. Multivariate logistic analysis of clinical-demographic factors and polymorphic genotypes demonstrated a correlation between FSH levels and polymorphic genotypes of SERPINE1 in poor response status.

CONCLUSIONS

Despite a higher prevalence of AMHR2, LHCGR, MTHFR, and SERPINE1 variations in the patients with poor ovarian response, it seems that these variations are not associated with the ovarian response.

PAI-1 4G/4G Genotype Is Associated with Recurrent Implantation Failure: a Systematic Review and Meta-analysis

To detect the association between PAI-1 -675 4G/5G polymorphism and recurrent implantation failure (RIF). We performed this meta-analysis by searching databases of PubMed, EMBASE, OVID, and CNKI (China National Knowledge Infrastructure) for case-control studies that evaluated the association between PAI 4G/5G polymorphism and RIF. Meta-analysis was performed using the random-effects model. The odds ratios (ORs) with 95% confidence intervals (CIs) were reported to evaluate the association. Meta-regression and subgroup analysis were performed to explore the source of heterogeneity. Sensitivity analysis and trim-and-fill analysis were performed to explore the robustness of the meta-analysis. Eight case-control studies consisted of 1273 women were included in this meta-analysis (including 697 RIF patients and 576 control participants). The combined results showed that the homozygous genotype of PAI-1 -675 4G/4G was significantly associated with RIF (OR 2.79, 95%CI 1.53-5.08, P-value = 0.0008). Meta-regression and subgroup analysis showed that sample origin is the primary source of heterogeneity (P-value for meta-regression: 0.005). Study quality also explains some heterogeneity (P-value for meta-regression: 0.03). Sensitivity analysis showed that the result was not significantly changed after excluding one study each time. Trim-and-fill analysis showed that the result was not significantly changed after filled with three studies. PAI -675 4G/4G genotype may serve as one of the predisposing factors of RIF. Women with PAI-1 4G/4G genotype were at higher risk of RIF. However, more high-quality studies are needed to confirm the conclusion.

Thromboprophylaxis in pregnant women with thrombophilia and a history of thrombosis

Background Despite intensive research, thromboembolism still accounts for significant maternal morbidity and mortality. We examined thrombophilia in patients with thromboembolism during pregnancy and evaluated the efficiency of antithrombotic prophylaxis in patients with thrombophilia for the prevention of recurrent thromboembolism. Materials and methods Sixty-eight women with a history of thromboembolism were managed during pregnancy, in light of their thrombotic history and the result of thrombophilia assessment. Group I (n=50) received prophylaxis with low molecular weight heparin (LMWH)±aspirin (50-100 mg/day) in preconception period or from the 1st trimester, during pregnancy and at least 6 weeks postpartum. Group II (n=18) received LMWH±aspirin from the II to III trimester. Results Thromboses were associated with pregnancy in 27 patients (39.7%), with systemic diseases - in nine (13.2%), oral contraceptives use - 22 (32.3%), immobilization due to surgery and/or trauma, long flight - six (8.9%), septic complications - two (2.9%). Nevertheless, 24.5% of patients had no apparent provoking factor for the development of thrombotic complications. Thirty-seven (54%) patients with venous thromboembolism (VTE) had familial history of VTE, and 25 (36.7%) had personal history of pregnancy complications (fetal loss syndrome, preeclampsia and placental abruption) (P<0.05 vs. control). Thrombophilia was detected in 58 (85.3%). Usual thrombogenic polymorphisms [factor V (FV) Leiden and prothrombin G20210A, heterozygous forms] were revealed in 16 (23.5%) and eight (11.7%) patients, respectively. Antiphospholipid antibodies (aPL) circulation was found in 34 (50%) patients. Non-usual thrombogenic polymorphisms were identified in 44 (64.7%) of the women and hyperhomocysteinemia - in 30 (44.2%). In group I no one had severe obstetric complications. All the patients were delivered at term and all the babies were alive. In group II moderate-to-severe obstetric complications were noted: preeclampsia - in 11 (16.2%), severe preeclampsia - seven (10.3%), preterm delivery - in 18 (26.4%) patients from subgroup II (P<0.05). Conclusions Women with a personal or a family history of thromboembolism and obstetric complications should be screened for thrombophilia. Beginning anticoagulant therapy early in such patients is effective not only for preventing recurring thrombosis but also preventing obstetric complications. Late prophylaxis after the completion of the trophoblast invasion therapy is much less effective.

Association of Plasminogen Activator Inhibitor-1 Gene Polymorphisms and Methylene Tetrahydrofolate Reductase Polymorphisms with Spontaneous Miscarriages

AIM

The objective of this study was to investigate a possible correlation between the plasminogen activator inhibitor-1 (PAI-1) and methylene tetrahydrofolate reductase (MTHFR) polymorphisms and unexplained spontaneous miscarriages (SM).

MATERIALS AND METHODS

PAI-1 polymorphisms were evaluated in 150 women with pregnancy in their history. One hundred women with a history of SM formed the study group and 50 women with normal pregnancies served as the control group. Also, the combination of PAI-1 and MTHFR polymorphisms were evaluated in 138 women out of a total of 150, which included 92 women with SM in their history compared to 46 women in the control group. For statistical analysis, χ2 test, Phi, and Cramer V tests were used; p < 0.05 was taken as a statistically significant result.

RESULTS

Our findings show: (a) the correlation between SM and PAI-1 mutations reaches statistical significance (p = 0.026); (b) there was a statistically significant difference between heterozygous PAI-1 in women with only 1 SM compared to the control group (p = 0.047); (c) the comparison of combinations of both mutations, PAI-1 and MTHFR, with the control group demonstrates statistical significance in favor of women with SM and both mutations (p = 0.022).

CONCLUSION

PAI-1 and MTHFR polymorphisms may play an important role in pregnancy complications because heterozygous PAI-1 mutations and a combination of both PAI-1 and MTHFR mutations might contribute to SM.

Role of Plasminogen Activator Inhibitor Type 1 in Pathologies of Female Reproductive Diseases

Normal pregnancy is a state of hypercoagulability with diminishing fibrinolytic activity, which is mainly caused by an increase of plasminogen activator inhibitor type 1 (PAI-1). PAI-1 is the main inhibitor of plasminogen activators, including tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA). In human placentas, PAI-1 is expressed in extravillous interstitial trophoblasts and vascular trophoblasts. During implantation and placentation, PAI-1 is responsible for inhibiting extra cellular matrix (ECM) degradation, thereby causing an inhibition of trophoblasts invasion. In the present study, we have reviewed the literature of various reproductive diseases where PAI-1 plays a role. PAI-1 levels are increased in patients with recurrent pregnancy losses (RPL), preeclampsia, intrauterine growth restriction (IUGR), gestational diabetes mellitus (GDM) in the previous pregnancy, endometriosis and polycystic ovary syndrome (PCOS). In general, an increased expression of PAI-1 in the blood is associated with an increased risk for infertility and a worse pregnancy outcome. GDM and PCOS are related to the genetic role of the 4G/5G polymorphism of PAI-1. This review provides an overview of the current knowledge of the role of PAI-1 in reproductive diseases. PAI-1 represents a promising monitoring biomarker for reproductive diseases and may be a treatment target in the near future.

Associations between Maternal and Fetal Inherited Thrombophilias, Placental Characteristics Associated with Vascular Malperfusion, and Fetal Growth

Pregnancy results in alterations in coagulation processes, which may increase the risk of thrombosis. Inherited thrombophilia mutations may further increase this risk, possibly through alterations in the placenta, which may result in pregnancy complications such as poor fetal growth. The purpose of our study is to evaluate the association of fetal growth, approximated by birth weight for gestational age percentile, with genetic markers of thrombophilia and placental characteristics related to vascular malperfusion. We analyzed data from the Stillbirth Collaborative Research Network's population-based case–control study conducted in 2006–2008. Study recruitment occurred in five states: Rhode Island and counties in Massachusetts, Georgia, Texas, and Utah. The analysis was restricted to singleton, nonanomalous live births ≤42 weeks' gestation with a complete placental examination and successful testing for ≥1 thrombophilia marker (858 mothers, 902 infants). Data were weighted to account for oversampling, differential consent, and availability of placental examination. We evaluated five thrombophilia markers: factor V Leiden, factor II prothrombin, methylenetetrahydrofolate reductase A1298C and C677T, and plasminogen activator inhibitor type 1 in both maternal blood and placenta/cord blood. We modeled maternal and fetal thrombophilia markers separately using linear regression. Maternal factor V Leiden mutation was associated with a 13.16-point decrease in adjusted birth weight percentile (95% confidence interval: −25.50, −0.82). Adjustment for placental abnormalities related to vascular malperfusion did not affect the observed association. No other maternal or fetal thrombophilia markers were significantly associated with birth weight percentile. Maternal factor V Leiden may be associated with fetal growth independent of placental characteristics.

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.

Evaluation of cardiac risk marker levels in obese and non-obese patients with polycystic ovaries

OBJECTIVE

To compare cardiac risk markers such as asymmetric dimethyl arginine (ADMA), C-reactive protein (CRP), homocystein (Hcy), plasminogen activator inhibitor-1 (PAI-1), vascular endothelial growth factor (VEGF), angiopoietin-related growth factor 6 (ANGPTL6) in obese and non-obese patients with polycystic ovary syndrome (PCOS).

STUDY DESIGN

Thirty obese (BMI >30 kg/m²) and 30 non-obese (BMI < 30 kg/m²) patients diagnosed with PCOS and 30 age-matched healthy controls were included in the study. The ages of subjects were varying between 18 and 30 years. Serum ADMA, CRP, Hcy, PAI-1, VEGF and ANGPTL6 levels were analyzed for each subject.

RESULTS

Serum ADMA, CRP, Hcy, PAI-1, VEGF and ANGPTL6 levels were significantly elevated in obese and non-obese women with PCOS in comparison to control subjects (p < 0.05). This elevation was more obvious in the obese PCOS group than in the other group.

CONCLUSIONS

Cardiovascular risk markers such as ADMA, CRP, Hcy, PAI-1, VEGF and ANGPTL6 levels are elevated in women with PCOS.

PAI-1 polymorphism as a cause of severe high altitude associated arteriovenous thrombosis

We present a 34-year-old man who developed disseminated intra-arterial and venous thrombosis following exposure to extreme high altitude. On evaluation, the patient was found to have thrombosis involving the aorta, bilateral iliac arteries and middle cerebral artery. On detailed evaluation for the cause of recurrent seizures, he was also found to have cerebral venous thrombosis of the superior sagittal sinus. The patient underwent amputation of 3 limbs due to gangrene. Procoagulant work up revealed increased plasminogen activator inhibitor-1 activity with 4G/4G polymorphism. This case highlights the life-threatening and limb-threatening thrombosis secondary to a rare inherited thrombophilia on exposure to extreme high altitude.

Factor V Leiden, prothrombin G20210A, and methylene tetrahydrofolate reductase mutations and stillbirth: the Stillbirth Collaborative Research Network

BACKGROUND

An evaluation for heritable thrombophilias is recommended in the evaluation of stillbirth. However, the association between thrombophilias and stillbirth remains uncertain.

OBJECTIVE

We sought to assess the association between maternal and fetal/placental heritable thrombophilias and stillbirth in a population-based, case-control study in a geographically, racially, and ethnically diverse population.

STUDY DESIGN

We conducted secondary analysis of data from the Stillbirth Collaborative Research Network, a population-based case-control study of stillbirth. Testing for factor V Leiden, prothrombin G20210A, methylene tetrahydrofolate reductase C677T and A1298C, and plasminogen activating inhibitor (PAI)-1 4G/5G mutations was done on maternal and fetal (or placental) DNA from singleton pregnancies. Data analyses were weighted for oversampling and other aspects of the design. Odds ratios (OR) were generated from univariate models regressing stillbirth/live birth status on each thrombophilia marker.

RESULTS

Results were available for ≥1 marker in 488 stillbirths and 1342 live birth mothers and 405 stillbirths and 990 live birth fetuses. There was an increased odds of stillbirth for maternal homozygous factor V Leiden mutation (2/488; 0.4% vs 1/1380; 0.0046%; OR, 87.44; 95% confidence interval, 7.88-970.92). However, there were no significant differences in the odds of stillbirth for any other maternal thrombophilia, even after stratified analyses. Fetal 4G/4G PAI-1 (OR, 0.63; 95% confidence interval, 0.43-0.91) was associated with decreased odds of stillbirth. Other fetal thrombophilias were similar among groups.

CONCLUSION

Most maternal and fetal thrombophilias were not associated with stillbirth. Maternal factor V Leiden was weakly associated with stillbirth, and the fetal PAI-1 4G/4G polymorphism was associated with live birth. Our data do not support routine testing for heritable thrombophilias as part of an evaluation for possible causes of stillbirth.

High Maternal Body Mass Index in Early Pregnancy and Risks of Stillbirth and Infant Mortality-A Population-Based Sibling Study in Sweden

In a population-based case-control study, we investigated whether familial confounding influenced the associations between maternal overweight/obesity and risks of stillbirth and infant mortality by including both population and sister controls. Using nationwide data from the Swedish Medical Birth Register (1992–2011), we included all primiparous women with singleton births who also had a sister with a first birth during that time period. We used logistic regression analyses to calculate odds ratios (and 95% confidence intervals) adjusted for maternal age, height, smoking habits, education, and time period (5-year groups) of child's birth. Body mass index (BMI) was calculated as weight (kg)/height (m)². Compared with population controls with a normal BMI (18.5–24.9), stillbirth risk increased with increasing BMI (BMI 25–29.9: odds ratio (OR) = 1.51 (95% confidence interval (CI): 1.21, 1.89); BMI 30–34.9: OR = 1.77 (95% CI: 1.24, 2.50); BMI ≥35: OR = 3.16 (95% CI: 2.10, 4.76)). The sister case-control analyses revealed similar results. Offspring of obese women (BMI ≥30) had an increased risk of infant mortality when population controls were used (OR = 2.41, 95% CI: 1.83, 3.16), and an even higher risk was obtained when sister controls were used (OR = 4.04, 95% CI: 2.25, 7.25). We conclude that obesity in early pregnancy is associated with increased risks of stillbirth and infant mortality independently of genetic and early environmental risk factors shared within families.

Pregnancy Loss, Polycystic Ovary Syndrome, Thrombophilia, Hypofibrinolysis, Enoxaparin, Metformin

Thrombophilia, hypofibrinolysis, and polycystic ovary syndrome (PCOS) are associated with recurrent pregnancy loss (RPL) and spontaneous abortion (SAB) alone and concurrently. The efficacy and safety of combined enoxaparin-metformin was prospectively assessed in women with PCOS with one or more previous SAB, thrombophilia, and/or hypofibrinolysis. Twenty-four white women with PCOS were studied; 23 with previous pregnancies, seven with RPL of unknown etiology (≥ three consecutive pregnancy losses <20 weeks’ gestation), two with two consecutive SABs, 13 with one SAB, and one with one live birth (HELLP syndrome). Prospectively, metformin (1.5 to 2.55 g/day) was administered before and throughout gestation, with concurrent enoxaparin (60 mg/day) throughout gestation. The 24 cases differed from 93 normal white female controls for the factor V Leiden mutation, 17% vs. 2%, Fisher’s p [pf] = .016, and for the 4G4G mutation of the plasminogen activator inhibitor-1 (PAI-1) gene (46% vs. 24%, Chi-square 4.63, p =. 031). The patients also differed from 44 normal white female controls for high levels (> 21.1 U/mL) of the PAI-1 gene product, plasminogen activator inhibitor activity (PAI-Fx) (33% vs. 8%, pf =. 018), and for high factor VIII (>150%) (22% vs. 0%, pf = .037). Of the 24 women, 23 had 65 previous pregnancies without metformin or enoxaparin, with 18 live births, 46 SAB (71%), and one elective abortion. On metforminenoxaparin, the same 23 women had 26 current pregnancies (28 fetuses), with 20 live births, two normal pregnancies 13 weeks or longer, and six SAB (21%), 3.4-fold lower than previous gestations (McNemar’s S = 33.6, p <. 0001). There were no adverse maternal or fetal therapy effects. Enoxaparin-metformin reduces pregnancy loss in women with PCOS with one or more previous SAB, who also have thrombophilia and/or hypofibrinolysis.

A Case of Unexplained Cerebral Sinus Thrombosis in a 22-Year-Old Obese Caucasian Woman

Herein, we present the case of a 22-year old obese Caucasian woman female with no acquired thrombophilic risk factors who was diagnosed with extensive cerebral sinus thrombosis. A detailed thrombophilia workup demonstrated persistently elevated plasminogen activator inhibitor 1 (PAI-1) activity levels, with an elevated PAI-1 antigen concentration and homozygosity for the PAI-1 4G allele (4G/4G genotype). The patient was treated with indefinite warfarin anticoagulation medication due to the unprovoked nature of her thrombotic event. Disturbances in the fibrinolytic system, in particular PAI-1, have been related to an increased risk of arterial and venous thrombosis. In this article, we discuss the pathophysiology of hypofibrinolysis associated with elevated PAI-1 levels and the PAI-1 4G/5G polymorphism.

Plasminogen Activator Inhibitor-1 4G/5G Polymorphism is Associated with Reproductive Failure: Metabolic, Hormonal, and Immune Profiles

PROBLEM

Association between PAI-1 4G/5G polymorphism and reproductive failures has been postulated. We aimed to investigate its impact on metabolic, hormonal, and immune profiles of women with reproductive failures.

METHOD OF STUDY

A retrospective study was carried out in 208 women with a history of reproductive failure. Study patients were divided into three groups: women with repeated implantation failure (RIF, n = 40), recurrent pregnancy loss (RPL, n = 113), and both RIF and RPL (n = 55). Fertile controls were 92.

RESULTS

PAI-1 4G/4G was prevalent in RPL, RIF, and RIF/RPL groups when compared with controls (P = 0.003) and associated with increased risks of RIF, RPL, and RIF with RPL (OR = 4.5, 2.2 and 2.7). Women with PAI-1 4G/4G have significantly higher BMI, glucose, and PAI-1 levels and lower NK cytotoxicity when compared with women without PAI-1 4G/4G.

CONCLUSION

PAI-1 4G/5G polymorphism plays a major role in the pathogenesis of RPL and RIF by altering metabolic and immunological profiles.

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.

Genetic association of five plasminogen activator inhibitor-1 (PAI-1) polymorphisms and idiopathic recurrent pregnancy loss in Korean women

Plasminogen activator inhibitor-1 (PAI-1) is important for maintaining pregnancy. Aberrantly increased PAI-1 levels may contribute to thrombosis and inflammation, leading to pregnancy loss. This study investigated the association of PAI-1 polymorphisms (PAI-1 rs2227631 [-844G>A], rs1799889 [-675 4G/5G], rs6092 [43G>A], rs2227694 [9785G>A], and rs7242 [11053T>G]) with idiopathic recurrent pregnancy loss (RPL) in Korean women. We screened 308 RPL patients and 227 control participants for five PAI-1 polymorphisms. Genotyping of PAI-1 was performed by polymerase chain reaction-restriction fragment length polymorphism assay. PAI-1 4G4G and -844AA/4G4G/11053GG genotypes were associated with RPL. PAI-1 -844A/4G/43G/9785G/11053G haplotype was connected to hypofibrinolytic status (i.e. increased levels of plasma PAI-1, increased numbers of platelets, reduced prothrombin time, and reduced activated partial thromboplastin time). Moreover, PAI-1 11053TG+GG frequency was positively related to plasma homocysteine and urate levels, whereas -844AA frequency was associated with plasma folate concentrations according to ordinal logistic regression analysis. Based on these results, we propose that PAI-1 -844G>A, 4G/5G, and 11053T>G polymorphisms are markers of RPL.

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.

Association of plasminogen activator inhibitor-type 1 (-675 4G/5G) polymorphism with pre-eclampsia: systematic review

BACKGROUND AND AIMS

Excessive generation of plasminogen activator inhibitor-type 1 (PAI-1) is implicated in the pathogenesis of pre-eclampsia and related conditions. The PAI-1 (-675 4G/5G) promoter polymorphism (rs1799889) affects transcriptional activity and is a putative genetic risk factor for pre-eclampsia. The aim of this study was identify, appraise and synthesise the available evidence for the association of the PAI-1 (-675 4G/5G) polymorphism with pre-eclampsia.

METHODS

Systematic review and random effects meta-analysis of genetic association studies.

RESULTS

We found 12 eligible genetic association studies in which a total of 1511 women with pre-eclampsia, eclampsia or HELLP syndrome and 3492 controls participated. The studies were generally small (median number of cases 102, range 24 to 403) and underpowered to detect plausible association sizes. Meta-analysis of all of the studies detected statistically significant gene-disease associations in the recessive [pooled odds ratio 1.28 (95% confidence interval 1.09, 1.50); population attributable risk 7.7%] and dominant [pooled odds ratio 1.21 (95% confidence interval 1.01, 1.44); population attributable risk 13.7%] models. We did not find evidence of statistical heterogeneity, funnel plot asymmetry or small study bias.

CONCLUSIONS

These data suggest that the fibrinolytic pathway regulated by the PAI-1 gene may contribute to the pathogenesis of pre-eclampsia and related conditions. This association, if confirmed in larger genetic association studies, may inform research efforts to develop novel interventions or help to prioritise therapeutic targets that merit evaluation in randomised clinical trials.

Association between the SERPINE1 (PAI-1) 4G/5G insertion/deletion promoter polymorphism (rs1799889) and pre-eclampsia: a systematic review and meta-analysis

The SERPINE1 -675 4G/5G promoter region insertion/deletion polymorphism (rs1799889) has been implicated in the pathogenesis of pre-eclampsia (PE), but the genetic association has been inconsistently replicated. To derive a more precise estimate of the association, a systematic review and meta-analysis was conducted. This study conformed to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed (MEDLINE), Scopus and HuGE Literature Finder literature databases were systematically searched for relevant studies. Summary odds ratios (ORs) and 95% confidence intervals (CIs) were calculated for the allelic comparison (4G versus 5G) and genotypic comparisons following the co-dominant (4G/4G versus 5G/5G and 4G/5G versus 5G/5G), dominant (4G/4G+4G/5G versus 5G/5G) and recessive (4G/4G versus 4G/5G+5G/5G) genetic models. Between-study heterogeneity was quantified by I(2) statistics and publication bias was appraised with funnel plots. Sensitivity analysis was conducted to evaluate the robustness of meta-analysis findings. Meta-analysis of 11 studies involving 1297 PE cases and 1791 controls found a significant association between the SERPINE1 -675 4G/5G polymorphism and PE for the recessive genetic model (OR = 1.36, 95% CI: 1.13-1.64, P = 0.001), a robust finding according to sensitivity analysis. A low level of between-study heterogeneity was detected (I(2) = 20%) in this comparison, which may be explained by ethnic differences. Funnel plot inspection did not reveal evidence of publication bias. In conclusion, this study provides a comprehensive examination of the available literature on the association between SERPINE1 -675 4G/5G and PE. Meta-analysis results support this polymorphism as a likely susceptibility variant for PE.

Role of tissue plasminogen activator and plasminogen activator inhibitor polymorphism in myocardial infarction

A case-control association study on 229 Myocardial Infarction (MI) patients and 217 healthy controls was carried out to determine the role of tissue-plasminogen activator (t-PA) (Alu-repeat insertion (I)/deletion (D)) and plasminogen activator inhibitor (PAI-1) (4G/5G insertion/deletion) polymorphisms with MI in the Pakistani population. In MI patients the genotype distribution of the PAI-1 gene was not found to be different when compared with the unaffected controls (P>0.05, χ2=1.03). The risk allele 4G was also not associated with MI (P>0.05, χ2=0.46, odds ratio (OR)=1.1 (95% confidence interval (CI)=0.84-1.43), P>0.05). Similarly, the genotype frequencies of t-PA I/I, I/D and D/D were not different from the unaffected controls (P>0.05, χ2=1.60), and the risk allele "I" was not found to be associated with MI (P>0.05, χ2=1.35, OR=0.86 (95% CI=0.66-1.11), P>0.05). However, when the data were distributed along the lines of gender a significant association of the 4G/4G PAI-1 genotype was observed with only the female MI patients (P<0.05, z-test=2.21). When the combined genotypes of both the polymorphisms were analyzed, a significant association of MI was observed with the homozygous DD/4G4G genotype (P<0.01, z-test=2.61), which was specifically because of the female samples (P=0.01, z-test=2.53). In addition smoking (P<0.001, χ2=13.52, OR=3.45 (95% CI=1.77-6.94)), diabetes (P<0.001, χ2=22.45, OR=8.89 (95% CI=2.96-29.95)), hypertension (OR=7.76 (95% CI=2.88-22.68), P<0.001) family history (P<0.001, χ2=13.72, OR=3.7 (95% CI=1.71-8.18)) and lower HDL levels (P<0.05) were found to be significantly associated with the disease. In conclusion the PAI-1 gene polymorphism was found to have a gender specific role in the female MI patients.

Plasminogen Activator Inhibitor I 4G/5G Polymorphism in Neonatal Respiratory Distress Syndrome

Fibrin monomers inhibit surfactant function. 4G/5G insertion/deletion polymorphism plays an important role in the regulation of plasminogen activator inhibitor 1 (PAI-1) gene expression. To examine the genotype distribution of PAI-1 polymorphism in 60 infants with respiratory distress syndrome (RDS) and 53 controls, an allele-specific polymerase chain reaction (PCR) was used. The proportion of 4G/4G, 4G/5G, and 5G/5G genotypes did not differ statistically between the RDS and control groups (P > .05). Having PAI-1 4G/4G genotype polymorphism appears to increase the risk of RDS (odds ratio [OR] =1.5; 95% confidence interval [CI], 0.5-4.3), although it was not statistically significant. No relation was found between the PAI-1 4G/5G polymorphisms and RDS, but there was an increased risk associated with the 4G variant of the PAI-1 gene. We believe that our findings of increased 4G allele of the PAI-1 gene in infants with RDS would also help to clarify the pathogenesis of RDS.

Angiotensin-converting enzyme D/I and plasminogen activator inhibitor-1 4G/5G gene polymorphisms are associated with increased risk of spontaneous abortions in polycystic ovarian syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a main cause of infertility, particularly in high-risk settings such as spontaneous abortions (SAB). We aimed to evaluate the effect of genetic polymorphisms in ACE and plasminogen activator inhibitor-1 (PAI-1) on the occurrence of SAB in PCOS.

METHODS

One hundred and forty-two PCOS patients (83 women have a history of one or more unexplained SAB, 59 women have successfully live births) and 107 healthy controls matched for age and body mass index were included in the study. Levels of PAI-1, LH, FSH, testosterone, fasting glucose and insulin were measured. ACE deletion (D)/insertion (I) and PAI-1 4G/5G gene polymorphisms were performed.

RESULTS

The D/D and/or 4G/4G genotype frequency, the D or 4G allelic frequency, the combination of the ACE D/D and PAI-1 4G/5G, D/I and 4G/4G genotypes of PCOS patients with SAB women were statistically higher than non-SAB group (p<0.05). The 4G/4G or D/D genotype of PCOS with SAB patients had significantly higher PAI-1 levels than non-SAB women.

CONCLUSIONS

The ACE D/I and PAI-1 4G/5G gene polymorphisms might represent risk factor in PCOS with SAB. Homozygosity for ACE D or PAI-1 4G polymorphisms as well as compound carrier status are significant positive explanatory variable for PCOS patients with SAB, which may result in increased PAI-1 concentrations and hypofibrinolysis and contribute to early pregnancy loss.

The plasminogen activator inhibitor-1 (PAI-1) gene -844 A/G and -675 4G/5G promoter polymorphism significantly influences plasma PAI-1 levels in women with polycystic ovary syndrome

Mutations in the plasminogen activator inhibitor-1 (PAI-1) gene, along with increased PAI-1 levels, have been implicated in the pathogenesis of polycystic ovarian syndrome (PCOS). We investigated a possible influence of the promoter polymorphism (-844 A/G and -675 4G/5G) in the PAI-1 gene on plasma PAI-1 levels in 126 PCOS patients and 97 healthy controls. Levels of total testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH), fasting plasma glucose (FPG), fasting insulin, and PAI-1 were measured, and body mass index (BMI), waist-to-hip ratio (WHR), LH/FSH ratio, and homeostasis model assessment for insulin resistance (HOMA-IR) were calculated. PAI-1 -675 4G/5G and -844 A/G gene polymorphisms were also performed. Total testosterone, fasting insulin, and PAI-1 levels; BMI, LH/FSH, and HOMA-IR were significantly higher in PCOS patients than controls (P < 0.05). The odds ratio of 4G/4G genotype, 4G allele, and the combination genotype of 4G/4G and -844 A/A were 2.49 (95% confidence interval (CI), 1.4-4.44), 2.1 (95% CI, 1.43-3.08), and 2.9 (95% CI, 1.41-5.98), respectively, (P < 0.001). In the PCOS group, the PAI-1 level of the A/A was significantly higher than that of the A/G or G/G genotype, similarly was 4G/4G genotype compared with 4G/5G or 5G/5G genotype. The plasma PAI-1 levels of the combination of the PAI-1 -844 A/A and -675 4G/4G or 4G/5G genotypes, or the coadunation of 4G/4G and -844 non-G/G (A/A + A/G) genotypes were significantly high in PCOS women compared with controls. A trend to a positive interaction between PAI-1 -675 4G/5G and -844 A/G gene polymorphism may elevate plasma PAI-1 levels and hypofibrinolysis, which is probably an important hereditary risk factor in PCOS.

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

PROBLEM

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

METHOD

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

RESULTS

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

CONCLUSION

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

Are polymorphisms in the ACE and PAI-1 genes associated with recurrent spontaneous miscarriages?

PROBLEM

To determine whether the ACE D/D genotype or the combination of PAI-1 4G/4G and ACE D/D genotypes may serve as a risk factor for recurrent pregnancy loss.

METHOD OF STUDY

Buccal swabs were obtained from 120 women experiencing recurrent pregnancy loss and from 84 fertile control women. DNA was extracted from the buccal swab samples using the Qiagen DNA Mini Kit (Qiagen), followed by multiplex polymerase chain reaction (PCR). PCR products were analyzed for the ACE gene polymorphism, which consists of the insertion or deletion (I/D) of a 287-bp fragment in intron 16, and the PAI-1 4G/4G genotype.

RESULTS

No significant differences in specific ACE gene mutations were observed when patients experiencing recurrent miscarriage were compared with control women. When the frequencies of homozygous mutations for ACE D/D and PAI-I 4G/4G were compared between recurrent aborters and controls, again no significant differences in the prevalence of the combination of these gene mutations were noted.

CONCLUSION

Homozygosity for the D allele of the ACE gene and the combination of the D/D genotype with two 4G alleles of the PAI-1 promoter gene are not associated with a significant increase in the risk of recurrent miscarriage.

Enoxaparin-metformin and enoxaparin alone may safely reduce pregnancy loss

Polycystic ovary syndrome (PCOS), thrombophilia, and hypofibrinolysis are associated with recurrent pregnancy loss (RPL) and spontaneous abortion (SAB). In 28 Caucasian women, 21 women with PCOS (4 with previous thrombosis, 18 with 1 SAB or more, and 20 with 1 coagulation disorder or more), and 7 women with coagulation disorders-thrombi, we speculated that prospective treatment with enoxaparin-metformin or enoxaparin alone would successfully and safely promote healthy live births compared with previous untreated pregnancies. In 21 women with PCOS, metformin (1.5-2.55 g/day) was given before and during pregnancy with concurrent enoxaparin (60 mg/day). Of 21 PCOS women, 19 women had 40 previous untreated pregnancies, 7 had live births (18%), 3 had elective abortions (ABs) (8%), and 30 had SABs (75%). On enoxaparin-metformin, these 19 women had 24 pregnancies, 20 live births (83%), and 4 SABs (17%); the SAB rate was 4.4-fold lower than previous untreated pregnancies (McNemar's s = 20.8, P < 0. 0001). Two women with PCOS without previous pregnancies, but with previous thrombosis, had 2 pregnancies on enoxaparin-metformin and 2 live births. Of the 7 women with coagulation disorders-thrombi, 4 had 15 previous pregnancies without enoxaparin, with 6 live births (40%), 8 SABs (53%), and 1 elective AB (7%). On enoxaparin, these 4 women had 4 pregnancies, with 4 (100%) live births (McNemar's s = 8.0, P = 0.005). The other 3 women with coagulation disorders-thrombi had 4 pregnancies on enoxaparin with 4 live births. No adverse maternal-fetal side effects were reported on enoxaparin alone or enoxaparin-metformin. Enoxaparin-metformin reduces pregnancy loss in women with PCOS-coagulation disorders and in women with coagulation disorders-thrombi.

Inferior Vena Cava Agenesia and a Massive Bilateral Iliofemoral Venous Thrombosis

The absence of the inferior vena cava is a rare congenital anomaly and represents a modest risk for deep-venous thrombosis. When associated with genetic polymorphism or other hypercoagulable states, the risk can increase several times. A case of young man with the inferior vena cava agenesia and deep-venous thrombosis of both legs triggered by the physical effort is reported. The view that the congenital inferior vena cava malformation represents a predisposition to deep-venous thrombosis in spite of well-developed collateral circulation is supported. In these circumstances, various external triggers (physical effort, hormonal contraception etc) may precipitate thrombosis. Because the patient had no other convincing and permanent risk factors for thrombosis, the lifelong anticoagulant therapy was not recommended.

Epistatic interactions are critical to gene-association studies: PAI-1 and risk for mortality after burn injury

Replication of statistically significant associations between single nucleotide polymorphisms (SNPs) and disease phenotypes has been problematic. One reason for conflicting observations may be failure to consider confounding factors, including gene-gene (epistatic) interactions. Our experience with the insertion/deletion polymorphism at -688 in the promoter region of plasminogen activator inhibitor (PAI-1) seems to support this contention and may foreshadow problems for genome-wide association scans, which tend to use unadjusted analytical methodologies. One hundred forty-nine patients with > or =15% total body surface area (TBSA) burns, without significant nonburn-related trauma (injury severity score < or =16), traumatic or anoxic brain injury or spinal cord injury who survived >48 hours postadmission were enrolled under a protocol approved by the UT Southwestern and Parkland Hospital IRBs. Clinical data were collected prospectively and candidate polymorphisms in PAI-1 (-688), toll-like receptor 4 (+896), CD14 (-159), tumor necrosis factor-alpha (-308), and interleukin-6 (-174) were genotyped. The PAI-1 SNP was significantly associated (P-value for trend = 0.036) with risk for death when evaluated in isolation by unadjusted analysis. However, after adjustment for potential confounders using multiple logistic regression, only age, full-thickness burn size, and CD14 genotype (as previously reported) were associated with increased mortality. Genetic association analyses should be adjusted for interactions between multiple SNPs, injury or disease characteristics, and demographic variables. Increasingly sophisticated analytical methods will be required as gene-mapping studies transition from a candidate-gene based approach to genome-wide association scans.

Association between 49 infant gene polymorphisms and preterm delivery

The occurrence of preterm delivery has been increasing in the U.S. Previous studies have identified risk factors for preterm delivery that may have genetic influences. We conducted a case-control study comparing the frequencies of 49 genetic polymorphisms among 62 preterm infants and 553 term infants. The polymorphisms that we examined were involved in xenobiotic-metabolism, blood pressure, coagulation, the inflammatory response, cell-cell interaction, or folate-homocysteine metabolism. Univariate analyses on the individual polymorphisms revealed a statistically significant effect for the variant genotypes compared to the wildtype genotypes in SERPINE1 11053G > T (OR = 0.4, 95% CI = 0.2-0.8). This finding suggests the coagulation/thrombophilic pathway may influence the development of preterm delivery.

4G/5G polymorphism of PAI-1 gene and Alu-repeat I/D polymorphism of TPA gene in Turkish patients with polycystic ovary syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is one of the most encountered endocrine malfunctions. PCOS patients have enhanced activation of the blood coagulation system.

METHODS

Eighty-six young women with PCOS and 70 healthy control women were included in our study. PCOS patients and controls were matched for age, body mass index, and allele frequency. Genetic analysis of TPAI and PAI-1 were performed in all subjects.

RESULTS AND CONCLUSIONS

No statistically significant differences have been detected about the ratios of genotypes resulting from PAI-1 promotor 4G/5G gene polymorphism. PAI-1 765 4G/5G gene polymorphism and TPA gene's Alu-repeat insertion/deletion (I/D) polymorphism ratios were not different from the controls. In this study it is shown by the analysis of TPA gene's Alu-repeat insertion/deletion (I/D) polymorphism the PCOS patients with genotype II had lowers total cholesterol and LDL-cholesterol levels.

Recurrent pregnancy loss: the key potential mechanisms

Recurrent pregnancy loss (RPL), which occurs in 0.5%-1% of total pregnancies, is usually defined as three or more consecutive spontaneous abortions before 20 weeks of gestation. Although an immunology-based etiology underlying unexplained RPL has been demonstrated, the exact molecular mechanisms are still poorly understood. Recent studies using transcriptomics and proteomics have implicated several factors. Here, we review the key possible mechanisms, in particular immunological abnormalities and thrombophilic aberration, that might underlie RPL. Taken together, these findings provide insight into the development of effective therapeutics for RPL.

Fibrinolytic defects and recurrent miscarriage: a systematic review and meta-analysis

OBJECTIVE

To systematically review evidence of the association between fibrinolytic defects and recurrent miscarriage.

DATA SOURCES

MEDLINE, EMBASE, and references of retrieved articles (last update September 2006) were used.

METHODS OF STUDY SELECTION

Studies comparing the prevalence of fibrinolytic defects in patients with recurrent miscarriage and control women were reviewed. Of 111 potentially relevant studies, data from 14 were integrated with meta-analytic techniques and were presented as odds ratios (ORs).

TABULATION, INTEGRATION, AND RESULTS

Plasminogen activator inhibitor-1 4G/5G polymorphism (OR 1.65, 95% confidence interval [CI] 0.92-2.95) and increased plasminogen activator inhibitor activity were not significantly associated with recurrent miscarriage, although the latter showed profound heterogeneity across studies. Although factor XII C46T polymorphism is not associated with recurrent miscarriage (OR 1.07, 95% CI 0.52-2.22), factor XII deficiency is significantly associated (five studies, 1,096 women; OR 18.11, 95% CI 5.52-59.39), with minimal heterogeneity across studies. Factor XIII Val34Leu and Tyr204Phe polymorphisms were not associated with recurrent miscarriage (OR 1.24, 95% CI 0.46-3.34 and OR 2.61, 95% CI 0.45-15.16, respectively). There were no eligible studies found for the rest of the factors searched (urokinase-type plasminogen activator, tissue-type plasminogen activator, kallicrein, a2-antiplasmin, a2-macroglobulin, thrombin-activated thrombolysis inhibitor, and factor XI). Only a small minority of studies ascertained miscarriage according to specific criteria, and none of the studies provided equal examination for confounders in cases and controls.

CONCLUSION

Factor XII deficiency is associated with recurrent miscarriage. Data on the other factors either fail to show association or are quite limited.

Thromboembolism in pregnancy: recurrence and its prevention

Fifteen to 25% of thromboembolic events in pregnancy are recurrent events. Women with a history of thrombosis have a three- to fourfold increased risk of recurrence when they are pregnant compared with when they are not. The risks are even higher postpartum. The rate of recurrent venous thromboembolic events without anticoagulation is 2.4% to 12.2%, whereas the rate with anticoagulation is 0% to 2.4%. Because the rates of recurrent thromboembolism can be reduced with anticoagulation, women with a history of thrombosis who are not on lifelong anticoagulation will likely require anticoagulation during pregnancy, or at least during the postpartum period. Women who are already on lifelong warfarin for the prevention of recurrent venous thromboembolism should be counseled about the teratogenic effects of warfarin and offered the opportunity to be converted to heparin before conception. During pregnancy, low-molecular-weight heparin, with fewer side effects and a longer half-life, is generally preferred over unfractionated heparin. Unfractionated heparin with its shorter half-life is generally preferred around the time of delivery. Women on antiplatelet medication for prevention of arterial thromboembolism may be converted to low-dose aspirin after conception and supplemented with low-dose heparin or low-molecular-weight heparin during pregnancy. Because current recommendations rely on case series and expert opinion, additional studies including randomized trials might enhance our ability to prevent recurrent thromboembolism in pregnancy.

Genetic polymorphisms and spontaneous preterm birth

OBJECTIVE

To examine whether selected genetic polymorphisms in the infant are associated with spontaneous preterm birth (less than 37 weeks) among children with or without later-diagnosed cerebral palsy.

METHODS

Exploratory case-control study investigating the relationship of gestational age at delivery to 31 single nucleotide polymorphisms measured in newborn screening bloodspots. Among all 443 children with later-diagnosed cerebral palsy born to white women in South Australia in 1986-1999, 234 were born after spontaneous onset of labor, and 108 of these were preterm (gestational age less than 37 weeks). The comparison group was 549 infants born after spontaneous onset of labor, of whom 147 were preterm. Distributions of genotypic frequencies were examined in preterm compared with term infants with and without cerebral palsy. Genotyping was performed using a Taqman assay.

RESULTS

In children without cerebral palsy, preterm birth after spontaneous onset of labor was more frequent in association with a variant of the beta2 adrenergic receptor gene (ADRB2 Q27E, P=.003), inducible nitric oxide synthase (iNOS or NOS2A, P=.042), or thrombomodulin (G127A, P=.006). Among children with cerebral palsy, preterm birth was associated with polymorphisms in genes for endothelial nitric oxide synthase (eNOS -922, P=.012), plasminogen activator inhibitor-2 (P=.015 and .019), and alpha adducin (ADD1, P=.047).

CONCLUSION

We confirm previous observations that variants of the beta adrenergic receptor and of nitric oxide synthase are associated with prematurity, and suggest that genetic variants of the placental antifibrinolytic plasminogen activator inhibitor-2, and thrombomodulin and alpha adducin may be contributors to risk of spontaneous preterm birth.

LEVEL OF EVIDENCE

II.

Which thrombophilic gene mutations are risk factors for recurrent pregnancy loss?

PROBLEM

Thrombophilia has been associated with poor obstetrical outcomes. To determine the association of specific inherited thrombophilias and recurrent pregnancy loss, 10 thrombophilic genes were investigated.

METHOD OF STUDY

A total of 550 women with a history of recurrent pregnancy loss had buccal swabs taken for DNA analyses of the following gene mutations: factor V G1691A, factor V H1299R (R2), factor V Y1702C, factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b(L33P), methylenetetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C. The frequencies of these mutations were compared with controls published in the literature.

RESULTS

When examined individually, PAI-1 4G/5G (P = 0.009), factor XIII V34L (P < 0.0001), and homozygous MTHFR C667T (P < 0.0001) correlated significantly with recurrent pregnancy loss compared with controls. The frequency of the factor V Y1702C mutation was extremely low in patients and controls; thus, this gene was removed from further calculations. The remaining six mutated genes, when analyzed cumulatively, also corresponded with recurrent pregnancy loss (P < 0.0001).

CONCLUSION

A panel of thrombogenic gene mutations consisting of factor V G1691A, factor V H1299R (R2), factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b(L33P), MTHFR C677T, and MTHFR A1298C can identify individuals at risk for recurrent pregnancy loss.

Genetic polymorphism in the fibrinolytic system and endometriosis

OBJECTIVE

Although most women experience retrograde menses during their reproductive life, endometriosis develops only in a small percentage. We hypothesized that persistence of a fibrin matrix in peritoneal pockets, as a result of hypofibrinolysis, could allow menstrually deposited endometrial fragments to initiate endometriosis. Fibrinolysis is modulated by several factors, and polymorphisms in the plasminogen activator inhibitor-1 (PAI-1) gene are considered to be one of the important determinants. The objective of this study was to evaluate PAI-1 genotypes in a group of women with or without endometriosis.

METHODS

In 118 women (75 with laparoscopically confirmed endometriosis and 43 controls), genomic DNA was extracted from blood and the PAI-1 promoter genotype was determined by polymerase chain reaction amplification of DNA using specific primers for the 4G or 5G allele followed by gel electrophoresis. A portion of the polymerase chain reaction product was purified and sequenced to confirm the gel electrophoresis results.

RESULTS

Endometriosis was more likely in patients with 4G/5G (odds ratio 38; 95% confidence interval [CI] 6-229) or 4G/4G (odds ratio 441; 95% CI 53-3,694) compared with 5G/5G PAI-1 genotype. Fifty-two of 75 women with endometriosis (69 %, 95% CI 58-79%) had the 4G/4G genotype compared with only 5 of 43 (12%; 95% CI 4-25%) controls. In contrast, the 5G/5G genotype associated with normal fibrinolysis was found in 2 of 75 (3%; 95% CI 0-9%) women with endometriosis compared with 24 of 43 (56%; 95% CI 40-71%) controls.

CONCLUSION

Hypofibrinolysis, associated with the 4G allele of the PAI-1 gene, was found significantly more often in women with endometriosis compared with controls. Persistence of fibrin matrix could support the initiation of endometriotic lesions in the peritoneal cavity, explaining why some women with retrograde menstruation develop endometriosis while others do not.

LEVEL OF EVIDENCE

II-2.

Multiple thrombophilic gene mutations rather than specific gene mutations are risk factors for recurrent miscarriage

PROBLEM

Recurrent miscarriage is a heterogeneous condition. While the role of acquired thrombophilia has been accepted as an etiology of recurrent miscarriage, the contribution of specific inherited thrombophilic genes to this disorder has remained controversial. We compared the prevalence of 10 thrombophilic gene mutations among women with a history of recurrent miscarriages and fertile control women.

METHOD OF STUDY

A total of 150 women with a history of two or more recurrent pregnancy losses and 20 fertile control women with no history of pregnancy losses had buccal swabs taken for DNA analyses of 10 gene mutations [factor V G1691A, factor V H1299R (R2), factor V Y1702C, factor II prothrombin G20210A, factor XIII V34L, beta-fibrinogen -455G>A, PAI-1 4G/5G, HPA1 a/b (L33P), MTHFR C677T, MTHFR A1298C]. The prevalence of these mutations was compared between women experiencing recurrent miscarriage and controls.

RESULTS

No differences in the frequency of specific gene mutations were detected when women with recurrent miscarriage were compared with control women. However, the prevalence of homozygous mutations and total gene mutations among patients with recurrent miscarriage was significantly higher than among controls. Homozygous mutations were found in 59% of women with a history of recurrent pregnancy loss contrasted to 10% of control women. More than three gene mutations among the 10 genes studied were observed in 68% of women with recurrent miscarriage and 21% of controls.

CONCLUSION

Inherited thrombophilias are associated with recurrent miscarriage. This association is manifest by total number of mutations rather than specific genes involved.

Polycystic ovarian syndrome--prognosis and outcomes

Polycystic ovarian syndrome (PCOS) is a condition that is present in 5-6% of women of reproductive age. It has potentially profound implications for women with regard to anovulatory infertility and symptoms related to elevated androgen levels. In addition, in later life women are prone to significant health problems related to hyperinsulinaemia, with an excess risk for diabetes and cardiovascular risk factors. Evidence suggests that the adverse features of PCOS can be ameliorated with lifestyle intervention, such as diet and exercise, while further short-term benefits related to ovulation and cardiac risk factors may be derived from medication with metformin. Evidence for the long-term use of metformin to protect against adverse cardiovascular outcomes and for the use of metformin throughout pregnancy to reduce the risk of miscarriage, gestational diabetes, pre-eclampsia and fetal macrosomia is still lacking.

Plasminogen activator inhibitor activity, 4G5G polymorphism of the plasminogen activator inhibitor 1 gene, and first-trimester miscarriage in women with polycystic ovary syndrome

We assessed whether hypofibrinolytic plasminogen activator inhibitor 1 (PAI-1 activity) showed an independent association with first-trimester miscarriage in the 430 women with polycystic ovary syndrome (PCOS) who had previous pregnancies (from a cohort of 967 women with PCOS). Prospectively, we hypothesized that Glucophage (Bristol-Myers Squibb, Princeton, NJ) promotes successful live births in women with PCOS by lowering PAI-1 activity before conception and maintaining further reductions of PAI-1 activity during the first trimester of pregnancy. We also assessed whether PAI-1 activity levels were independently related to PAI-1 genotype and to modifiable risk factors body mass index (BMI), insulin, and triglyceride. By stepwise logistic regression, with the dependent variable being previous pregnancy outcomes at 3 levels (live birth pregnancies only [n = 208]; both > or =1 live birth and > or =1 first-trimester miscarriage [n = 111]; or first-trimester miscarriages only [n = 71]) and explanatory variables PAI-1 genotype, PAI-1 activity, insulin, homeostasis model assessment of insulin resistance, BMI, and triglyceride, PAI-1 activity was positively associated with first-trimester miscarriage (P = .004). For each 5 IU/mL increment in PAI-1 activity, the risk being in an adverse first-trimester miscarriage category increased (odds ratio, 1.12; 95% confidence interval, 1.04-1.20). Prospectively, from pretreatment to the last preconception visit on Glucophage, in 30 women who subsequently had live births, PAI-1 activity fell 44%, but rose 19% in 23 women with first-trimester miscarriage (P = .03). In the 30 women with live birth pregnancies, median PAI-1 activity fell continuously from pretreatment through the first trimester (from 16.8 to 6.7 IU/mL), whereas PAI-1 activity was either unchanged or rose in women with first-trimester miscarriage. Of the 921 women with PCOS who had 4G5G data, 718 (78%) had 4G4G-4G5G genotypes vs 87 (69%) of 126 normal female controls (chi(2) = 4.95, P = .026). The 4G allele frequency was 53% in women with PCOS vs 46% in controls (chi(2) = 4.3, P = .04). Of the 866 women with PCOS who had PAI-1 activity data, by stepwise regression, positive independent determinants of PAI-1 activity included BMI (partial R(2) = 10.6%, P < .0001), insulin (partial R(2) = 2.8%, P < .0001), triglyceride (partial R(2) = 1.1%, P = .0009), and the 4G4G-4G5G genotype (partial R(2) = 1%, P = .0011). The PAI-1 gene 4G polymorphism is more common in women with PCOS than in normal women and, in concert with obesity, hyperinsulinemia, and hypertriglyceridemia, contributes to treatable, hypofibrinolytic, miscarriage-promoting, high PAI-1 activity. Preconception and first-trimester decrements in PAI-1 activity on Glucophage are associated with live births, whereas increments or no change in PAI-1 activity despite Glucophage appears to be associated with first-trimester miscarriage.

Multiple thrombophilic gene mutations are risk factors for implantation failure

While the role of inherited thrombophilia has been accepted as a cause of recurrent late pregnancy complications, the contribution of mutated thrombophilic genes to implantation failure has not been studied. Proteins involved in fibrinolysis are necessary for trophoblast invasion into the endometrium. This study compared the prevalence of 10 thrombophilic gene mutations among 42 women with a history of recurrent implantation failure after IVF-embryo transfer with 20 fertile control women. Buccal swabs were taken from all of the women for DNA analyses. Women with a history of implantation failure after IVF-embryo transfer displayed a higher prevalence of PAI-1 4G/5G mutations than controls (P = 0.007). No differences in the frequency of the other specific gene mutations were detected. However, the prevalence of total gene mutations among patients with implantation failure was significantly higher than among controls. More than three gene mutations among the 10 genes studied were observed in 74% of women with implantation failure and 20% of controls (P = 0.0004). It is concluded that inherited thrombophilias are associated with implantation failure. This association is manifest by total number of mutations as well as with PAI-1 mutations.

A systematic review of the association between factor V Leiden or prothrombin gene variant and intrauterine growth restriction

OBJECTIVE

The purpose of this study was to conduct a systematic review of the literature of studies that examined the association between factor V Leiden and/or prothrombin gene variant and intrauterine growth restriction.

STUDY DESIGN

This systematic review of studies assesses the association between factor V Leiden and/or prothrombin gene variant and intrauterine growth restriction.

RESULTS

Ten case-control studies fulfilled the selection criteria for inclusion in the meta-analysis. There was a significant association between factor V Leiden and intrauterine growth restriction (odds ratio, 2.7; 95% CI, 1.3-5.5) and prothrombin gene variant and intrauterine growth restriction (odds ratio, 2.5; 95% CI, 1.3-5.0). Five cohort studies were identified in the systematic review; 3 studies were prospective (2 full publications), and 2 studies were retrospective (1 full publication). Combining the 2 full publication prospective studies yields a summary relative risk of 0.99 (95% CI, 0.5-1.9).

CONCLUSION

This meta-analysis of case-control studies suggests that the factor V Leiden and prothrombin gene variant both confer an increased risk of giving birth to an intrauterine growth restricted infant, although this may be driven by small, poor-quality studies that demonstrated extreme associations. Large well-conducted prospective cohort studies are required to determine definitively whether an association between thrombophilia and intrauterine growth restriction is present.

Prenatal screening for thrombophilia: the background and the approach

Coagulation is a normal response to blood vessel injury and involves the interaction of endothelium, platelets and clotting factors. Coagulation is altered by pregnancy and may be further altered by thrombophilia, an acquired or inherited predisposition to develop thrombosis. An overview of coagulation is provided as background for understanding thrombophilia. Both acquired and genetic risk factors for thrombosis are discussed. Thrombosis may affect not only the maternal circulation, but the utero-placental-fetal circulation as well. The literature documenting the association between maternal thrombosis and thrombophilia is summarized, as is the recent data linking thrombophilia and poor pregnancy outcome. An approach to screening for thrombophilia is outlined and strategies for thromboprophylaxis are provided.