Pregnancy Failure and Heritable Thrombophilia

Pregnancy and thrombosis risk for women without a history of thrombotic events: a retrospective study of the real risks

Background

During pregnancy and puerperium women are at high VTE risk. Current guidelines recommend dynamic VTE-risk assessment during pregnancy. Based on related RCOG-guidelines we constructed a digital VTE-risk assessment tool: PATrisks (www.PATrisks.com). Using this tool, we retrospectively evaluated the thrombotic risk in 742 women from our previous work, women who received thromboprophylaxis based on clinical experience for A) pregnancy complications, B) IVF treatment and C) prothrombotic tendency, in order to investigate whether that practice was justified according to the PATrisks scoring system for VTE prevention.

Methods

Women with pregnancy complications [Group-A: 445], women who had undergone IVF [Group-B:132] and women with a prothrombotic tendency (thrombophilia, family history of VTE, other) [Group-C:165] were assessed using the PATrisks scoring system for thrombotic risk. The women were assigned into one of the following risk categories: low (score ≤ 2), intermediate (score = 3) and high (score ≥ 4). Further analysis per risk factor type (pre-existing or obstetric) and for various combinations of them, was also performed. We evaluated thrombotic risk early in pregnancy, and in the peripartum period.

Results

The mean risk score antepartum was higher for women in Group B (3.3 in comparison with 1.9 and 2.0 in Group A and Group C respectively). Moreover, the risk score increased significantly postpartum for all Groups. The chi-square test also proved that there was a higher percentage of women at high or intermediate risk in group B compared to C before birth (55.3% vs.26.1% respectively, p < 0.0001, OR: 3.5, 95% CI: 2.2 – 5.7) and similarly after birth (85.6% vs. 56.4%, OR: 4.6, 95%CI: 2.6–8.2, p < 0.0001). In total 12 (1.6%) out of 742 women experienced thrombotic events, whether pre- or post-partum.

Conclusions

LMWHs are widely prescribed during pregnancy for a number of indications, even when a proven scientific basis for such a practice is lacking. However, a considerable percentage of women were already at VTE-risk according to PATrisks and might have derived an additional benefit from LMWH in the form of VTE prevention. The rational use of these drugs should be optimized by establishing and implementing routine risk assessment for all pregnant women and by providing the necessary education to healthcare professionals.

Low molecular weight heparins use in pregnancy: a practice survey from Greece and a review of the literature

Background

Use of LMWH in pregnancy is not only limited to VTE management, but it extends, to the management of vascular gestational complications and the optimization of IVF pregnancies despite the lack of concrete scientific evidence. In this context, we conducted the present study aiming to gain insights regarding the use of LMWH during pregnancy and puerperium. We recorded indication for use, diagnostic work-up as well as the safety and efficacy of the treatment, trying to elucidate the clinical practice in our country.

Methods

We analyzed data regarding 818 pregnant women received LMWH during 2010-2015.Our cohort had a median age of 33.9 years and a BMI of 23.6.There were 4 groups: those with a history of VTE [Group-A: 76], those with pregnancy complications [Group-B: 445], those undergoing IVF [Group-C: 132] and those carrying prothrombotic tendency (thrombophilia, family history of VTE, other) [Group-D: 165]. Mean duration of LMWH administration was 8.6 ± 1.5 months. Out of the total number, 440 received LMWH in fixed prophylactic dose, 272 in higher prophylactic-weight adjusted dose and 106 in therapeutic dose. Moreover, 152 women received in addition low-dose acetylsalicylic acid (ASA). 93.8% of pregnancies were single and 6.2% were multiple ones. Live births occurred in 98.7% of pregnancies.

Results

Anticoagulation was efficacious and well tolerated. Seventeen VTE events were recorded; 7 of them antepartum and 10 postpartum. No major bleeding events were observed while 13 clinical relevant non-major bleeding events were recorded. Regarding gestational vascular complications, 28 IUGR events were recorded, as well as 48 cases of preterm labor of which 12 were concomitant with IUGR (25%). Six early pregnancy losses were recorded; there were 3 fetal deaths and 3 cases of pre-eclampsia/eclampsia.

Conclusions

LMWHs are used extensively during pregnancy and puerperium in Greece for VTE treatment and prophylaxis and for a variety of other indications as well. Although the drug has been shown to be both safe and efficacious, its use for some indications has no proven scientific evidence. In order to clearly define the role of LMWHs in pregnancy, beyond thromboprophylaxis, large prospective studies are required, which could be based on the conclusions of this study.

Pharmacological Effect of Quercetin in Hypertension and Its Potential Application in Pregnancy-Induced Hypertension: Review of In Vitro, In Vivo, and Clinical Studies

Since improving maternal and child health is a public health priority worldwide, the main aim of treatment of hypertension in pregnant women is to prevent complications during pregnancy, labor, and postpartum. In consequence, much attention is paid to the use of antihypertensive drugs that can be used safely during pregnancy. Several side effects of methyldopa, which is currently the most commonly used antihypertensive drug in pregnant women, mean that the search for an effective and safe alternative still continues. Flavonoid compounds present in medicinal plants, vegetables, and fruits may be a promising source of new drugs. In this aspect, quercetin, a well-known flavonoid due to its antihypertensive action, may be considered a prototype for safe antihypertensive drugs. This review focuses on the selective activity of quercetin. Based on recent studies, a few problems were discussed, including (1) pathology of pregnancy-induced hypertension; (2) search for new pharmacological treatments of pregnancy-induced hypertension; (3) issues with the use of herbal extracts during pregnancy; (4) flavonoids as natural active chemical compounds; (5) quercetin: its action during pregnancy, in vitro and in vivo pharmacological activities, clinical trials, and meta-analysis; (6) quercetin intake during pregnancy; (7) other natural compounds tested during pregnancy; (8) potential problems with the use of quercetin; (9) safety profile of quercetin. Various studies have shown a beneficial effect of quercetin on vascular endothelial function and its antioxidative and anti-inflammatory activity on cellular and tissue level. It is known that in animal models quercetin affects positively the development of embryo, fetus, and placenta. Because this flavonoid did not have teratogenic and abortive effect, it is generally recognized as safe. For this reason it should be appreciated and studied in the aspect of its potential use in the prevention and treatment of pregnancy-induced hypertension among women in this risk group.

Maternal carriers of the ANXA5 M2 haplotype are exposed to a greater risk for placenta-mediated pregnancy complications

PURPOSE

Annexin A5 (ANXA5) is a protein abundantly expressed in normal placenta where it contributes to the healthy outcome of a pregnancy. Lower ANXA5 levels have been observed in M2/ANXA5 haplotype carrying chorion. Consequently, this study aimed to assess the potential association of M2 maternal carrier status with the risk of recurrent pregnancy loss (RPL), the timing of miscarriages, and other obstetric complications, for the first time in a population from Latin America.

METHODS

This study was designed as a prospective recruitment of RPL patients with post hoc analysis. The distribution of the M2/ANXA5 haplotype was compared between a group of 229 Argentine women with RPL and 100 parous controls, and was further analyzed in subgroups of patients stratified according to the timing of miscarriages and in relation to other obstetric complications.

RESULTS

No significant differences were found in the distribution of M2 haplotype among either RPL patients or the subgroups with embryonic, early fetal, or late fetal losses compared to parous controls. Notwithstanding, maternal M2/ANXA5 was found to be independently associated with a higher risk of suffering intrauterine growth restriction (IUGR) and/or preeclampsia (PE). Simultaneously, the presence of inherited and/or acquired thrombophilia also proved to be an independent risk factor for these.

CONCLUSIONS

The association found between the maternal carriage of the M2/ANXA5 haplotype and an elevated risk of IUGR and/or PE supports the hypothesis that carrier status of this haplotype and the consequently reduced placental ANXA5 expression might be responsible, at least partially, for the onset of these gestational vascular complications.

Thrombophilia Screening: Universal, Selected, or Neither?

The utility of thrombophilia testing in clinical practice is still a matter of debate because studies have not shown a benefit in the reduction of recurrent venous thromboembolism (VTE) risk in patients with thrombosis, despite the clearly higher VTE risk for first thrombosis. Screening for thrombophilia is indicated in selected patients. Particularly in selected young patients, especially women of childbearing age, the knowledge of the genetic thrombophilic defect may help in specific situations to decrease the risk of VTE events. Avoidance of modifiable risk factors and/or prophylactic thromboembolic procedures may be evaluated in selected patients. A comprehensive workup including personal and familial history, clinical examination, and laboratory test results including hereditary thrombophilia remains helpful in assessing the cumulative risk and the management of this group of selected patients.

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.

Aspirin and heparin in pregnancy

INTRODUCTION

A pro-coagulant state during pregnancy can be involved in the occurrence of gestational vascular complications (GVCs) and venous thromboembolism (VTE).

AREAS COVERED

Antithrombotic drugs are used to prevent GVCs and VTE. Aspirin is not efficacious to prevent recurrences in women with previous early loss, while it can prevent pre-eclampsia in some groups of women. Heparins are not effective in the prevention of early recurrent loss and there is uncertainty about their efficacy in women carrying inherited thrombophilias. They could be efficacious in the prevention of GVCs in carriers of inherited thrombophilias, as GVCs have heterogeneous causes, and future studies have to focus on more homogeneous groups of patients. Not enough data are available regarding prophylaxis with heparins to prevent pregnancy-related VTE, but an accurate risk stratification of women during pregnancy and puerperium is crucial for administering prophylaxis in moderate-/high-risk women. Aspirin does not improve live births after assisted reproductive technologies, while heparins increase the number of clinical pregnancies and live births.

EXPERT OPINION

Aspirin is efficacious in the prevention of GVCs in women at risk for pre-eclampsia and in those with antiphospholipid antibodies syndrome. Heparins could give benefit to women at risk for GVCs and/or pregnancy-related VTE.

Meta-analysis of the association between plasminogen activator inhibitor-1 4G/5G polymorphism and recurrent pregnancy loss

Background

The association between plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism and recurrent pregnancy loss (RPL) risk is still contradictory. We thus performed a meta-analysis.

Material/Methods

Relevant studies were searched for in PubMed, Web of Science, Embase, and Cochrane Library. An odds ratio (OR) with a 95% confidence interval (CI) was used to assess the association between PAI-1 4G/5G polymorphism and RPL risk.

Results

A total of 22 studies with 4306 cases and 3076 controls were included in this meta-analysis. We found that PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk (OR=1.89; 95% CI 1.34–2.67; P=0.0003). In the subgroup analysis by race, PAI-1 4G/5G polymorphism was significantly associated with an increased RPL risk in Caucasians (OR=2.23; 95% CI 1.44–3.46; P=0.0003). However, no significant association was observed in Asians (OR=1.47; 95% CI 0.84–2.59; P=0.18).

Conclusions

In conclusion, this meta-analysis suggests that PAI-1 4G/5G polymorphism might be associated with RPL development in Caucasians.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Maternal and perinatal outcomes in spontaneous versus assisted conception twin pregnancies

OBJECTIVE

To compare maternal and perinatal outcomes in twin pregnancies conceived via assisted reproductive techniques (ART) compared with spontaneous twin pregnancies.

STUDY DESIGN

This retrospective study examined 345 dichorionic, di-amniotic twin pregnancies (207 conceived spontaneously and 138 conceived via ART), delivered between January 2007 and June 2011 at the San Pietro Fatebenefratelli Hospital, Rome, a tertiary medical centre. Maternal and perinatal outcomes were compared. A multiple logistic regression analysis was performed to calculate risk estimates as odds ratios (OR) adjusted for maternal age, parity and systemic diseases. Patient data were obtained from a computerized database and analyzed using Statistical Package for the Social Sciences Version 17.

RESULTS

Gestational age and birth weight were lower in the ART group, and preterm delivery, gestational diabetes and placental abruption were higher in the ART group compared with the spontaneous conception group. The incidence rates of respiratory complications, patent ductus arteriosus and admission to the neonatal intensive care unit were higher among ART newborns. Length of hospital stay for mothers and newborns was longer in the ART group. No differences in mode of delivery, Apgar score at 5min, congenital anomalies, perinatal mortality, and other considered pregnancy and neonatal complications were found between the two groups. Multivariate analysis adjusted for maternal age, parity and systemic diseases revealed that only the rates of placental abruption [OR 7.45, 95% confidence interval (CI) 2.05-26.98] and patent ductus arteriosus (OR 3.39, 95% CI 1.01-11.46) were significantly higher for the ART group.

CONCLUSIONS

Twin pregnancies conceived via ART are at greater risk of poorer outcomes than spontaneous twin pregnancies. This may be related to the type of conception and specific negative features of subfertile patients undergoing infertility treatment.

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.

Effects of low molecular weight heparin and heparin-binding epidermal growth factor on human trophoblast in first trimester

OBJECTIVE

To evaluate the effects of low molecular weight heparin (LMWH) and heparin-binding epidermal growth factor (HB-EGF) on the biological function of human trophoblast in first trimester.

DESIGN

Control experiment.

SETTING

Two academic-based reproductive centers.

PATIENT(S)

The first trimester human placentas (gestational age, 5-10 weeks) from patients who underwent electively induced abortions.

INTERVENTION(S)

Cultured trophoblast treated with LMWH or LMWH and HB-EGF.

MAIN OUTCOME MEASURE(S)

The biological function (proliferation, invasion, and differentiation) of trophoblast and the interaction between LMWH and HB-EGF on trophoblast in vitro.

RESULT(S)

1) At a dose of 0.25 IU/mL-2.5 IU/mL LMWH promoted trophoblast proliferation, enhanced their invasion, and increased hCG secretion. The LMWH had little effect or the opposite effect at other concentrations. These differences were statistically significant. 2) Combined use of LMWH and HB-EGF significantly promoted proliferation and invasion, but there was no difference in hCG secretion compared with solo LMWH or solo HB-EGF.

CONCLUSION(S)

The LMWH exerts a cytoprotective effect by regulating trophoblast proliferation, invasion, and differentiation. The HB-EGF is an important factor in the effects of LMWH on trophoblast function.

Evidence-based approach to thrombophilia testing

Thrombophilia can be identified in about half of all patients presenting with VTE. Testing has increased tremendously for various indications, but whether the results of such tests help in the clinical management of patients has not been settled. I use evidence from observational studies to conclude that testing for hereditary thrombophilia generally does not alter the clinical management of patients with VTE, with occasional exceptions for women at fertile age. Because testing for thrombophilia only serves limited purpose this should not be performed on a routine basis.

The significance of -786T > C polymorphism of endothelial NO synthase (eNOS) gene in severe preeclampsia

OBJECTIVE

Preeclampsia (PE) is believed to be induced by endothelial cell dysfunction in placenta. Highly polymorphic endothelial nitric oxide synthase (eNOS) activity belongs to the factors significantly influencing vaso-motor tone in placenta and PE susceptibility. The aim of this study was to evaluate prevalence of -786T/C polymorphism of eNOS gene in the groups of women with mild and severe PE.

STUDY DESIGN

The study was performed in the group of 218 preeclamptic (including 136 with severe PE) and of 400 normotensive healthy women delivered normally after a healthy gestation. The eNOS -786T/C polymorphism was determined using PCR/RFLP assay. Additionally, detailed correlation between eNOS genotypes and clinical/laboratory data in the PE group has been analyzed.

RESULTS

The higher frequency of mutated homozygous CC genotypes (17.4% vs. 11.5% in controls, OR 1.62, n.s.) and of C alleles (allelic frequency 44.1 vs. 36.6%; OR 1.36, p = 0.012) in the group of PE has been determined. Furthermore, in the group of severe PE the overrepresentation of mutated CC genotypes (23.5% vs. 11.5%, OR 2.37, p = 0.0014) and mutated C alleles (47.8 vs. 36.6%, OR 1.58, p = 0.0016) has been found.

CONCLUSIONS

The presence of mutated homozygous CC genotype and C allele of -786T/C polymorphism of eNOS gene influences the higher susceptibility to develop severe PE development.

Polymorphisms of plasminogen activator inhibitor-1, angiotensin converting enzyme and coagulation factor XIII genes in patients with recurrent spontaneous abortion

We investigated polymorphisms of plasminogen activator inhibitor-1 (PAI-1), angiotensin converting enzyme (ACE ) and coagulation factor XIII (FXIII) genes and their association with recurrent spontaneous abortion (RSA) in Iranian patients and normal healthy controls. Ten (18.5%) patients were homozygote (4G/4G) for PAI-1 polymorphism, in contrast with two (2%) controls (p = 0.001). Patients with homozygote 4G mutation were significantly more prone to RSA in contrast to others (odds ratio: 11.0, 95% CI: 2.3-52.4). Nineteen (30.2%) patients and 25 (26.6%) controls were homozygote (DD) for ACE polymorphism. We observed only two patients and one control with homozygosity (34leu) for FXIII polymorphism. 4G/4G polymorphism for PAI-1 gene could be a thrombophilic mutation leading to abortion in Iranian population.

[Anticoagulation and thrombophilia in pregnancy]

A review of coagulation disturbances during pregnancy and the current management of the anticoagulated patient with heart valve prostheses, atrial fibrillation, and thromboembolic events is presented. All patients with mechanical heart valve prostheses require life-long oral anticoagulation with coumarin or one of its derivatives. Recommendations for the treatment and prevention of thromboembolic events are discussed. The advantages and disadvantages of three different treatment approaches to anticoagulation during pregnancy are discussed and recommendations for the management in different situations are outlined with delineation of specific risks for the mother and the fetus.

Patients' understanding of genetic susceptibility testing in mainstream medicine: qualitative study on thrombophilia

BACKGROUND

UK and US policy initiatives have suggested that, in the future, patients and clinicians in mainstream medicine could use genetic information to prevent common illnesses. There are no studies on patients' experience and understanding of the process of testing for common genetic susceptibilities in mainstream medicine.

METHODS

Qualitative interviews with 42 individuals who had undergone testing for a genetic susceptibility for deep vein thrombosis in primary and secondary care in the UK.

RESULTS

Some participants, often from higher social classes, had a good understanding of the test and its implications. They had often sought additional information on thrombophilia from relatives and from the Internet. Others, often from less privileged backgrounds, had a poorer understanding of the test--seven individuals were unaware of having had the genetic test. Features of genetic information led to misunderstandings: (i) at referral, (ii) when communicating results, and (iii) when making sense of the implications of testing. Participants' accounts indicated that non-specialist doctors may feel obliged to refer a patient for a genetic test they know little about, because a patient requests it after a relative had tested positive. Sometimes a referral for a genetic test was lost under information overload when multiple tests and issues were considered. The inconsistent and informal ways of communicating test results--for example by phone--in mainstream medicine also led to confusion. Participants did not generally overestimate their risk, but some were uncertain about whether they were taking the right preventive actions and/or whether their children were at risk. Information about genetic susceptibilities was difficult to make sense of, as it related to ambiguous risks for participants and family members, complicated and unfamiliar terminology and multiple genes and preventive strategies.

CONCLUSION

Policy visions of clinicians and patients in mainstream medicine seeking and using genetic information at their own initiative may not be realistic. Patients need more direct support in making sense of genetic information, if this information is to bring the anticipated health benefits, and not fuel health inequalities or create ethical problems. Clinicians in secondary and primary care need guidance to help them introduce genetic tests, communicate their results and explain their implications.