Hereditary thrombophilia and recurrent pregnancy loss: a retrospective cohort study of pregnancy outcome and obstetric complications

Thrombosis-related characteristics of pregnant women with antithrombin deficiency, protein C deficiency and protein S deficiency in Japan

BACKGROUND

 We previously conducted a primary survey of pregnant women with hereditary thrombophilia based on national surveillance in Japan, but did not examine their thrombosis-related characteristics. Antithrombin (AT) deficiency, protein C (PC) deficiency and protein S (PS) deficiency are the major types of hereditary thrombophilia in Japan.

METHODS

We examined their detailed information related to thrombosis, and evaluated peripartum outcomes in comparison with control data obtained from the Japan Society of Obstetrics and Gynecology.

RESULTS

Definite or probable AT deficiency, PC deficiency and PS deficiency were observed in 80, 50, and 317 pregnancies, respectively, from 2014 to 2018 in Japan, with prevalence rates among total deliveries of 0.011%, 0.007%, 0.044%. The number of pregnancies with AT, PC and PS deficiency might have been as many as 27, 17 and 108 every year if complete answers had been provided. In the peripartum period of current pregnancies, 27.5% of women with AT deficiency, 28.0% with PC deficiency and 13.2% with PS deficiency developed thrombosis (p < 0.001 vs. control). Pregnant women with AT and PC deficiency were more susceptible to thrombosis than those with PS deficiency (P < 0.01). Of the thromboses, 92.3% occurred during pregnancy, 62.8% at less than 15 gestational weeks. The earliest onset of thrombosis was 5 gestational weeks. Prophylactic anticoagulation significantly prevented the onset of both antepartum and postpartum thrombosis (p < 0.0001). The rate of recurrent pregnancy loss in women with low PC or PS activities was significantly higher than in controls (p < 0.0001); however, it is unknown whether recurrent pregnancy loss is related to hereditary PS deficiency. There seem to have been few serious maternal or fetal/neonatal complications due to placental insufficiency related to a hypercoagulable state other than growth restriction.

CONCLUSIONS

This survey revealed the thrombosis-related characteristics of pregnant women with hereditary thrombophilia in Japan. We suggest prophylactic anticoagulation to prevent maternal or fetal/neonatal complications.

Impact of Increased Activated Protein-C Resistance, Decreased Antithrombin III Activity and Hypocomplementemia on the Gestational Outcomes of Pregnancies with MTHFR Polymorphisms

OBJECTIVE

To evaluate the impact of increased Activated Protein C (APC) resistance, decreased antithrombin III activity and hypocomplementemia on the pregnancy outcomes of the patients with methylentetrahydrofolate reductase (MTHFR) polymorphisms.

METHODS

This study was composed of 83 pregnancies with MTHFR polymorphisms. Increased APC resistance, decreased antithrombin III activity and hypocomplementemia were accepted as risk factors for poor gestational outcome.

RESULTS

Having at least one risk factor resulted in significantly higher rates of "APGAR score of<7" at the first ten minutes (p=0.009). Composite adverse outcome rate was also higher in patients with at least one of the defined risk factors despite lack of statistical significance (p=0.241). Rate of newborn with an "APGAR score of<7" at first ten minutes was significantly higher at patients with hypocomplementemia (p=0.03).

CONCLUSION

Hypocomplementemia is a risk factor for poor gestational outcome in pregnancies with MTHFR polymorphisms.

Clinical guidance for peripartum management of patients with hereditary thrombophilia

Hereditary thrombophilia is a condition in which individuals are susceptible to the formation of thrombi due to a hereditary deficiency in anticoagulant factors, antithrombin (AT), protein C (PC), or protein S (PS). Many Japanese thrombophilia patients have PS deficiency, especially PS p.K196E (also called as PS Tokushima), which is exclusive to the Japanese population, and thrombosis sometimes occurs during pregnancy. At present, no management guidelines for pregnancy and delivery in thrombophilia patients have been developed. The Study Group for Hereditary Thrombophilia, one of the research groups of blood coagulation abnormalities in the Research Program on Rare and Intractable Diseases supported with the Research Grants of the Ministry of Health, Labour and Welfare Science, has therefore developed this clinical guidance to provide healthcare workers with necessary information on safe pregnancy, parturition and neonatal management, adopting a format of responses to seven clinical questions (CQ). At the end of each answer, the corresponding Recommendation Level (A, B, C) is indicated.

Pregnancy loss is associated with type 2 diabetes: a nationwide case-control study

AIMS/HYPOTHESIS

Type 2 diabetes is killing more people than ever, and early-life predictors remain critical for the development of effective preventive strategies. Pregnancy loss is a common event associated with later atherosclerotic disease and ischaemic heart failure and might constitute a predictor for type 2 diabetes. The objective of this study was to investigate whether pregnancy loss is associated with later development of type 2 diabetes.

METHODS

Using a Danish nationwide cohort, we identified all women born from 1957 through to 1997 and who had a diagnosis of type 2 diabetes during the period 1977 to 2017. The women were matched 1:10 on year of birth and educational level to women without diabetes in the general Danish population. Conditional logistic regression models provided odds ratios for type 2 diabetes with different numbers of pregnancy losses.

RESULTS

We identified 24,774 women with type 2 diabetes and selected 247,740 controls without diabetes. Women who had ever been pregnant (ever-pregnant women) with 1, 2 and ≥ 3 pregnancy losses had ORs of type 2 diabetes of 1.18 (95% CI 1.13, 1.23), 1.38 (95% CI 1.27, 1.49) and 1.71 (95% CI 1.53, 1.92) compared with ever-pregnant women with no pregnancy losses, respectively. Women who never achieved a pregnancy had an OR of type 2 diabetes of 1.56 (95% CI 1.51, 1.61) compared with ever-pregnant women with any number of losses. Similar results were found after adjustment for obesity and gestational diabetes.

CONCLUSIONS/INTERPRETATION

We found a significant and consistent association between pregnancy loss and later type 2 diabetes that increased with increasing number of losses. Thus, pregnancy loss and recurrent pregnancy loss are significant risk factors for later type 2 diabetes. Future studies should explore whether this association is due to common background factors or whether prediabetic metabolic conditions are responsible for this association. Graphical abstract.

Recurrent pregnancy loss: what is the impact of consecutive versus non-consecutive losses?

STUDY QUESTION

Is there a different prognostic impact for consecutive and non-consecutive early pregnancy losses in women with secondary recurrent pregnancy loss (RPL)?

SUMMARY ANSWER

Only consecutive early pregnancy losses after the last birth have a statistically significant negative prognostic impact in women with secondary RPL.

WHAT IS KNOWN ALREADY

The risk of a new pregnancy loss increases with the number of previous pregnancy losses in patients with RPL. Second trimester losses seem to exhibit a stronger negative impact than early losses. It is unknown whether the sequence of pregnancy losses plays a role for the prognosis in patients with a prior birth.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study of pregnancy outcome in patients with unexplained secondary RPL included in three previously published, Danish double-blinded placebo-controlled trials of intravenous immunoglobulin (IvIg) conducted from 1991 to 2014. No other treatments were given. Patients with documented explained pregnancy losses (ectopic pregnancies and aneuploid miscarriages) were excluded.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the 168 patients included in the trials, 127 had secondary RPL and experienced a subsequent live birth or unexplained pregnancy loss in the first pregnancy after giving informed consent to participate in the trials (the index pregnancy). Data analyzed by multivariate analysis included the independent variables age, the number of early pregnancy losses before and after the last birth, respectively and a second trimester pregnancy loss before or after the last birth, respectively. The outcome variable was unexplained loss in the index pregnancy.

MAIN RESULTS AND THE ROLE OF CHANCE

In patients with secondary RPL, both a late and each early loss before the last birth did not significantly influence the risk of a new pregnancy loss in the index pregnancy: incidence rate ratio (IRR) 1.31 (95% CI 0.62-2.77) and IRR 0.88 (95% CI 0.70-1.11), respectively. In contrast, the impact on risk of pregnancy loss conferred by a late and by each early pregnancy loss occurring after the birth was significant: IRR 2.15 (95% CI 1.57-2.94, P < 0.0001) and IRR 1.14 (95% CI 1.04-1.24, P = 0.002), respectively.

LIMITATIONS, REASONS FOR CAUTION

Of the patients, 48% were treated with IvIg, which could influence the results. However, allocation to IvIg was random and prognostic variables were equally distributed in IvIg and placebo-treated patients.

WIDER IMPLICATIONS OF THE FINDINGS

A birth in women with secondary RPL eradicates the negative prognostic impact of previous pregnancy losses and this finding is important for our understanding of the pathogenesis. It indicates that only consecutive pregnancy losses should count in the definition of RPL.

STUDY FUNDING/COMPETING INTERESTS

There was no particular funding for this study. The authors declare that there is no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable for two of the included randomized controlled trials. For the last trial: Clinical.Gov NCT00722475.

Frequency of hereditary thrombophilia in women with recurrent pregnancy loss in Northern Pakistan

AIM

Hereditary thrombophilia (HT) screening is performed as routine work-up of recurrent pregnancy loss (RPL) in Pakistan. In Northern Pakistan the prevalence of HT is not known. HT is not detected in the majority of RPL cases, especially in patients with ≤ 3 pregnancy losses (PL). The aim of this study was to determine the frequency of HT in women with RPL, and to find the prevalence of HT in patients with ≤ 3 PL and > 3 PL.

MATERIAL AND METHODS

Lupus-anticoagulant-negative patients with unexplained RPL were screened for protein C, protein S, antithrombin, and factor V Leiden.

RESULTS

A total of 315 patients with RPL were screened and 13 (4%) had evidence of HT. Protein C and protein S deficiency were detected in 6/140 (4.3%) women with > 3 PL and in 2/175 (1.1%) women with ≤ 3 PL. Antithrombin deficiency was detected in 2/140 (0.75%) women with > 3 PL and in no patients with ≤ 3 PL. Factor V Leiden was detected in 3/26 (12%) women with > 3 PL and in no patients with ≤ 3 PL. The prevalence of HT in patients with >3 PL was significantly higher than in patients with ≤ 3 PL (P = 0.002). We detected a strong association between HT and >3 PL (odds ratio 7.3; 95% confidence interval: 1.60-33.85) as compared to ≤ 3 PL.

CONCLUSION

HT was detected in 4% of patients with RPL. The prevalence of HT in patients with > 3 PL is significantly higher than in patients with ≤ 3 PL.

Recurrent spontaneous miscarriage is still a challenging diagnostic and therapeutic quagmire

Recurrent spontaneous miscarriage (RSM), affecting 1-2% of women of reproductive age seeking pregnancy, has been a clinical quagmire and a formidable challenge for the treating physician. There are many areas of controversy in the definition, aetiology, investigations and treatment of RSM. This review will address the many factors involved in the aetiology of RSM which is multifactorial in many patients, with antiphospholipid syndrome (APS) being the most recognized aetiological factor. There is no identifiable cause in about 40-60% of these patients, in which case the condition is classified as idiopathic or unexplained RSM. The RSM investigations are extensive and should be undertaken in dedicated, specialized, well-equipped clinics/centres where services are provided by trained specialists. The challenges faced by the treating physician are even more overwhelming regarding the decision of what should be the most appropriate therapy offered to patients with RSM. Our review will cover the diverse modalities of therapy available including the role of preimplantation genetic testing using recent microarray technology, such as single nucleotide polymorphism and comparative genomic hybridization, as well as preimplantation genetic diagnosis; the greatest emphasis will be on the treatment of APS, and there will be important comments on the management of patients presenting with idiopathic RSM. The controversial areas of the role of natural killer cells in RSM, the varied modalities in the management of idiopathic RSM and the need for better-planned studies will be covered as well.

Recurrent miscarriage is a useful and valid clinical concept

Although epidemiological, clinical and biochemical risk factors are known for recurrent miscarriage (RM), the etiology is mainly unknown. Two main hypotheses dominate: that RM is mainly caused by aneuploid conceptions and other conception errors and that the recurrence rate is explained by the combination of chance and increased risk, or that maternal endocrinological, thrombophilic or immunological abnormalities play a main role in causing loss of euploid conceptions. Believers of the former hypothesis advocate that management of RM should be conservative and that the spontaneous prognosis is very favorable. Believers of the latter hypothesis think that treatments aimed at the woman may improve pregnancy outcome, but that testing of such treatments in randomized controlled trials is needed. In this article in favor of RM being a specific and useful clinical concept, arguments are advanced that a significant subset of RM patients exhibit a poor spontaneous prognosis and should be offered relevant investigations, close surveillance during pregnancy, and treatment, preferably as part of randomized controlled trials.

Research methodology in recurrent pregnancy loss

The aim of this article is to highlight pitfalls in research methodology that may explain why studies in recurrent pregnancy loss (RPL) often provide very divergent results. It is hoped that insight into this issue may help clinicians decide which published studies are the most valid. It may help researchers to eliminate methodological flaws in future studies, which may hopefully come to some kind of agreement about the usefulness of diagnostic tests and treatments in RPL.

Antithrombotic therapy for pregnancy loss

BACKGROUND Although an association between thrombophilia and pregnancy loss has been observed in many studies, little is known about the pathophysiological mechanisms behind this association. Considering the association between thrombophilia and pregnancy loss, the efficacy of antithrombotic therapy for women with pregnancy loss (with or without thrombophilia) has been studied for the past 30 years. METHODS We performed a comprehensive review of the literature on the strength of the association between thrombophilia and pregnancy loss, the pathophysiological mechanisms and the efficacy of antithrombotic therapy to increase the chance of live birth. RESULTS The association between pregnancy loss and thrombophilia varies according to the type of thrombophilia (e.g. antiphospholipid syndrome versus forms of inherited thrombophilia) and according to the type of pregnancy loss (single versus recurrent pregnancy loss and early versus late pregnancy loss). Thrombophilia may induce thrombosis in decidual vessels or impair placentation through hypercoagulability and inflammation, but these hypotheses need further verification. For women with antiphospholipid syndrome, evidence from small-sized trials suggests a beneficial effect of antithrombotic therapy but additional randomized controlled trials are essential to confirm this. Whether antithrombotic therapy increases the chance of live birth in women with inherited thrombophilia is unknown. Recent randomized controlled trials have consistently shown that antithrombotic therapy does not increase the chance of live birth in women with unexplained recurrent miscarriage. CONCLUSIONS There are large gaps in knowledge and a lack of evidence for treatment of women with pregnancy loss with thrombophilia. To provide a solid base for clinical practice, further studies on the role of coagulation in reproduction, as well as international collaborations in randomized controlled trials of antithrombotic therapy in women with pregnancy loss, and antiphospholipid syndrome or inherited thrombophilia are urgently needed.

Recurrent miscarriage and thrombophilia: an update

PURPOSE OF REVIEW

Acquired and inherited thrombophilia is an important research avenue in the recurrent miscarriage field. The optimum treatment for patients with recurrent miscarriage and a confirmed thrombophilia remains a contentious issue. We aim to appraise and explore the latest research in the field of thrombophilia and recurrent miscarriage in this review.

RECENT FINDINGS

Antiphospholipid syndrome (APS) is the only proven thrombophilia that is associated with adverse pregnancy outcomes. Research involving inherited thrombophilia and recurrent miscarriage is limited to small observational studies with small and heterogeneous populations. Aspirin and heparin therapy are frequently prescribed for APS, yet there is no robust evidence for the most efficacious regime. The combination of inherited hypercoagulability and environmental factors in association with recurrent miscarriage has recently been explored as an aid to identify high-risk individuals.

SUMMARY

The cause of recurrent miscarriage is multifactorial and appropriate treatment continues to be a challenge. Laboratory tests need to be standardized and well designed multicentre research trials are essential to expand on the current knowledge base with the aim to produce strong evidence-based medicine.

[Antiphospholipid syndrome and pregnancy]

Antiphospholipid syndrome is characterized by arterial and venous thromboembolic events and persistent laboratory evidence of antiphospholipid antibodies. Obstetric complications such as recurrent miscarriage, early delivery, oligohydramnios, prematurity, intrauterine growth restriction, fetal distress, fetal or neonatal thrombosis, pre-eclampsia/eclampsia, and HELLP syndrome are also hallmarks of antiphospholipid syndrome. This syndrome is one of the diseases associated with the most severe thrombotic risk. Changes in the hemostatic system during normal pregnancy also result in a hypercoagulable state resulting in elevated thrombotic risk. Thromboembolic events are responsible of the vast majority of maternal and fetal deaths. Administration of appropriate thromboprophylaxis helps prevent thromboembolic complications during pregnancy in women with antiphospholipid syndrome and also give birth to healthy children. It is important to centralize the medication and management of these patients. It helps in the thoughtful care of these pregnant women encountering serious problems.

Laboratory referral rates of genetic tests for thrombophilia workup in a major referral center

AIMS

The rate of laboratory referrals for thrombophilia patients' genetic workup was assessed and compared among the medical and surgical specialties and subspecialties at a major tertiary care center in Lebanon.

METHODS

DNA extraction was performed using the PEL-FREEZ extraction kit (PEL-FREEZ; DYNAL) and the Factor V, prothrombin, and methylenetetrahydrofolate reductase genotypic profiles were done using the FV-PTH-MTHFR StripAssay kit (ViennaLab) that employs a polymerase chain reaction-reverse hybridization method. A total of 2238 referred cases were analyzed.

RESULTS

Around 42.23% of all referred cases turned out to have a thrombosis-associated mutation. Referrals from medical and surgical specialties were almost equal. In the surgical specialty, most referrals came from the department of Obstetrics and Gynecology, while in the medical speciality, most of the workup referrals originated from the Hematology/Oncology physicians. However, low referral rates were reported from the emergency department and family medicine practitioners.

CONCLUSION

Genetic testing for thrombophilia workup is gaining more importance among the different medical and surgical specialties and is worth being introduced into the offered test lists of all established molecular diagnostics laboratories.

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

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

Fertility, Infertility and Thrombophilia

Hypercoagulation has been reported in some studies to be associated with reproductive failures, such as unexplained infertility, IVF implantation failure and recurrent fetal losses. Many pregnancy-related disorders have been interpreted as consequences of impaired microvascular function and might be viewed as a mild form of venous thromboembolic disease. In the absence of clinical guidelines, there is a need for an evidence base regarding thrombophilic screening and antithrombotic therapy in cases of reproductive failure. This article will focus on the controversial effect of congenital and acquired thrombophilia on human fertility, and will review the English literature for relevant studies identified by searching PubMed® results between January 1966–November 2010 using the key words: ‘thrombophilia‘, ‘fertility’ and ‘infertility‘.