Third-trimester unexplained intrauterine fetal death is associated with inherited thrombophilia

Cause-Specific Stillbirth and Neonatal Death According to Prepregnancy Obesity and Early Gestational Weight Gain: A Study in the Danish National Birth Cohort

Maternal obesity is associated with impaired fetal and neonatal survival, but underlying mechanisms are poorly understood. We examined how prepregnancy BMI and early gestational weight gain (GWG) were associated with cause-specific stillbirth and neonatal death. In 85,822 pregnancies in the Danish National Birth Cohort (1996–2002), we identified causes of death from medical records for 272 late stillbirths and 228 neonatal deaths. Prepregnancy BMI and early GWG derived from an early pregnancy interview and Cox regression were used to estimate associations with stillbirth or neonatal death as a combined outcome and nine specific cause-of-death categories. Compared to women with normal weight, risk of stillbirth or neonatal death was increased by 66% with overweight and 78% with obesity. Especially deaths due to placental dysfunction, umbilical cord complications, intrapartum events, and infections were increased in women with obesity. More stillbirths and neonatal deaths were observed in women with BMI < 25 and low GWG. Additionally, unexplained intrauterine death was increased with low GWG, while more early stillbirths were seen with both low and high GWG. In conclusion, causes of death that relate to vascular and metabolic disturbances were increased in women with obesity. Low early GWG in women of normal weight deserves more clinical attention.

Association of hypertensive disorders of pregnancy risk and factor V Leiden mutation: A meta-analysis

AIM

To date, the conclusions of studies on a possible association between factor V Leiden (FVL, FV G1691A, rs6025) and hypertensive disorders of pregnancy (HDP) are conflicting. Here, we aimed to estimate the relationship between the risk of HDP and FVL.

METHODS

Eligible studies focused on FVL and HDP were searched from the PubMed and the Web of Science databases up to March 31, 2018. We used random effects model for the meta-analysis, and I² statistic to assess the degree of heterogeneity between all included studies. To evaluate the association between FVL and the risk of HDP, we calculated the odds ratio (OR) and 95% confidence intervals (CI) comparing cases and controls of all samples and each subgroup based on different regions.

RESULTS

Fifty citations on FVL and HDP were identified through the literature search, and a meta-analysis on the GA + AA genotype between 6041 cases and 8364 controls was conducted. The holistic analysis found that pregnant women with GA or AA genotype of FVL have a 1.97-fold (95% CI: 1.64-2.35, P < 0.00001) increased risk of HDP compared with GG carriers. While the OR are 2.23 (95% CI: 1.76-2.84, P < 0.00001) and 1.90 (95% CI: 1.12-3.23, P = 0.02) in Europe and the Middle East subgroups, respectively.

CONCLUSION

Factor V Leiden mutation is associated with an increased risk of HDP, and is particularly associated with preeclampsia and eclampsia in European women. However, further high-quality studies are warranted to confirm the possible effectiveness of FVL in HDP patients.

The Prevalence of Thrombophilia in Women With Recurrent Fetal Loss and Outcome of Anticoagulation Therapy for the Prevention of Miscarriages

OBJECTIVE

To estimate the prevalence of thrombophilia in women with recurrent miscarriages and to assess the effect of antithrombotic therapy.

DESIGN

A retrospective cohort study between the years 2004 and 2010.

SETTING

A hypercoagulation community clinic in northern Israel.

PATIENTS

Four hundred ninety pregnant women referred for thrombophilia screening.

MAIN OUTCOME MEASURES

Screening results for thrombophilia and antithrombotic treatment with enoxaparin, aspirin, or both and pregnancy outcomes.

RESULTS

The most common thrombophilia in our study group was factor V Leiden mutation with a prevalence of 20.9% followed by protein S deficiency with a prevalence of 19%. Live birth rate was higher in the group of women who received enoxaparin regardless of whether a specific thrombophilia could be found. This finding was more pronounced in women who had ≥4 miscarriages.

CONCLUSION

The prevalence of thrombophilia was higher in our study group than in the general population. Furthermore, treatment with enoxaparin might improve the rate of live births in women with or without evidence of thrombophilia, especially in women with ≥4 miscarriages.

Differences in thrombotic risk factors in black and white women with adverse pregnancy outcome

INTRODUCTION

Black women have an increased risk of adverse pregnancy outcomes and the characteristics of thrombotic risk factors in this population are unknown. The objective of this study was to examine the racial differences in thrombotic risk factors among women with adverse pregnancy outcomes.

METHODS

Uniform data were collected in women with adverse pregnancy outcomes (pregnancy losses, intrauterine growth restriction (IUGR), prematurity, placental abruption and preeclampsia) referred to Thrombosis Network Centers funded by the Centers for Disease Control and Prevention (CDC).

RESULTS

Among 343 white and 66 black women seen for adverse pregnancy outcomes, protein S and antithrombin deficiencies were more common in black women. The prevalence of diagnosed thrombophilia was higher among whites compared to blacks largely due to Factor V Leiden mutation. The prevalence of a personal history of venous thromboembolism (VTE) did not differ significantly by race. A family history of VTE, thrombophilia, and stroke or myocardial infarction (MI) was higher among whites. Black women had a higher body mass index, and a higher prevalence of hypertension, while the prevalence of sickle cell disease was approximately 27 fold higher compared to the general US black population.

CONCLUSIONS

Thrombotic risk factors differ significantly in white and black women with adverse pregnancy outcomes. Such differences highlight the importance of considering race separately when assessing thrombotic risk factors for adverse pregnancy outcomes.

Study of thrombophilia in recurrent pregnancy loss

OBJECTIVES

Recently, it has been found that women who have thrombophilia have increased risk of fetal loss. This study was designed to corroborate the association of elevated factor VIII level, protein C and protein S deficiencies, and the presence of LAC in women with recurrent pregnancy loss.

MATERIALS AND METHODS

53 patients with history of two or more pregnancy losses and 47 healthy age-matched subjects with no history of pregnancy loss and who have delivered at least one term infant without any complication were enrolled into the study.

RESULTS

Thrombophilic defect was present in 64.15 % of patients of study group. Protein S deficiency (50.94 %) was the most common thrombophilic defect observed. Spontaneous abortion (SA), preterm birth (PTB), and intrauterine growth retardation (IUGR) were the most important pregnancy complications observed. The strongest associations of pregnancy complications were observed with protein S deficiency (87.5 %) and with elevated factor VIII (66.66 %) level.

CONCLUSION

This study observed strong association of thrombophilia with unexplained recurrent pregnancy loss.

Relation between maternal thrombophilia and stillbirth according to causes/associated conditions of death

OBJECTIVE

To investigate maternal thrombophilia in cases of Stillbirth (SB), also an uncertain topic because most case series were not characterised for cause/associated conditions of death.

STUDY DESIGN

In a consecutive, prospective, multicentre design, maternal DNA was obtained in 171 cases of antenatal SB and 326 controls (uneventful pregnancy at term, 1:2 ratio). Diagnostic work-up of SB included obstetric history, neonatologist inspection, placenta histology, autopsy, microbiology/chromosome evaluations. Results audited in each centre were classified by two of us by using CoDAC. Cases were subdivided into explained SB where a cause of death was identified and although no defined cause was detected in the remnants, 64 cases found conditions associated with placenta-vascular disorders (including preeclampsia, growth restriction and placenta abruption - PVD). In the remnant 79 cases, no cause of death or associated condition was found. Antithrombin activity, Factor V Leiden, G20210A Prothrombin mutation (FII mutation) and acquired thrombophilia were analysed.

RESULTS

Overall, the presence of a thrombophilic defect was significantly more prevalent in mothers with SBs compared to controls. In particular, SB mothers showed an increased risk of carrying Factor II mutation (OR=3.2, 95% CI: 1.3-8.3, p=0.01), namely in unexplained cases. Such mutation was significantly associated also with previous SB (OR=8.9, 95%CI 1.2-70.5). At multiple logistic regression, Factor II mutation was the only significantly associated variable with SB (adj OR=3.8, 95% CI: 1.3-13.5).

CONCLUSION

These data suggest that Factor II mutation is the only condition specifically associated with unexplained SB and could represents a risk of recurrence. PVD-associated condition is unrelated to thrombophilia.

The Normal anticoagulant system and risk of placental abruption: protein C, protein S and resistance to activated protein C

OBJECTIVE

To examine the association between maternal thrombophilia associated with anticoagulation (proteins C and S and activated protein C resistance ratio, APCR) and risk of placental abruption.

METHODS

Data were derived from a case-control study - The New Jersey-Placental Abruption Study (2002-2007). Maternal blood was collected from abruption cases and controls and was assayed for the thrombophilias. Decreased protein C, S and APCR was defined as values <5% and <10% among controls.

RESULTS

Of a total of 132 cases and 127 controls, 3 were heterozygous for the factor V Leiden mutation (1 case and 2 controls). Mean (± standard deviation) protein C (114.2 ± 25.6 vs. 121.4 ± 27.6; P=0.009), protein S (39.9 ± 18.4 vs. 35.7 ± 15.2; P=0.043) and APCR (2.86 ± 0.29 vs. 2.88 ± 0.27; P=0.039) were different between cases and controls. Abruption cases were associated with an odds ratio of 3.2 (95% CI 1.2, 9.9) in relation to decreased protein C (<Fifth centile). Decreases in both protein S and APCR ratio were not associated with abruption.

CONCLUSIONS

A decrease in protein C was associated with an increased risk for abruption, suggesting an important role for the physiologic anticoagulant system in the etiology of placental abruption.

Prothrombin gene G20210A mutation and obstetric complications

OBJECTIVE

To estimate whether maternal carriage of the prothrombin gene G20210A mutation is associated with pregnancy loss, preeclampsia, placental abruption, or small for gestational age (SGA) neonates in a low-risk, prospective cohort.

METHODS

This was a secondary analysis of the Eunice Kennedy Shriver National Institute of Child Health and Human Development factor V Leiden study, a multicenter, prospective, observational cohort of 5,188 unselected singleton gestations. A total of 4,167 first-trimester samples were available for analysis and were tested for the prothrombin G20210A mutation. Obstetric complications were compared between women with and without the prothrombin G20210A mutation by univariable and multivariable analysis.

RESULTS

A total of 157 (3.8%) women had the prothrombin gene mutation (156 heterozygous and one homozygous). Carriers of the prothrombin G20210A mutation had similar rates of pregnancy loss, preeclampsia, SGA neonates, and abruption compared with noncarriers. Results were similar in a multivariable analysis controlling for age, race, prior pregnancy loss, prior SGA neonates, and family history of thromboembolism. Three thromboembolic events occurred in women testing negative for the mutation.

CONCLUSION

There was no association between the prothrombin G20210A mutation and pregnancy loss, preeclampsia, abruption, or SGA neonates in a low-risk, prospective cohort. These data raise questions about the practice of screening women without a history of thrombosis or adverse pregnancy outcomes for this mutation.

LEVEL OF EVIDENCE

II.

Natural coagulation inhibitors and active protein c resistance in preeclampsia

INTRODUCTION

The etiology of preeclampsia is not fully established. A few studies have shown a relationship between natural coagulation inhibitors and preeclampsia.

OBJECTIVES

The purpose of this study was to investigate the status of natural coagulation inhibitors and active protein C resistance (APC-R) in preeclampsia.

PATIENTS AND METHODS

We studied 70 women with preeclampsia recruited consecutively and 70 healthy pregnant and 70 nonpregnant women as controls. Plasma protein C (PC), free protein S (fPS), antithrombin III (ATIII) and APC-R were evaluated.

RESULTS

ATIII values were found to be significantly lower in preeclamptic patients than in the control groups (p< 0.001). Nevertheless, there was no significant difference between the healthy pregnant and nonpregnant women groups (p=0.141). The fPS values of the preeclamptic and healthy pregnant groups were lower than that of the nonpregnant group (p< 0.001), and the fPS value of the preeclamptic pregnant women was lower than that of healthy pregnant women (p<0.001). The PC value of the preeclamptic pregnant women was lower than that of the control groups (p< 0.001). The PC value of the healthy pregnant women was lower than that of the nonpregnant women (p< 0.001). The mean APC activity values were lower in the preeclamptic patients than that of the control groups (p< 0.001, p< 0.001). The APC-R positivity rates of the preeclamptic groups were higher than that of the control groups (p<0.001).

CONCLUSIONS

This study demonstrated that ATIII, fPS, PC values and APC resistance were lower and APC-R positivity was higher in preeclamptic women than in normal pregnant and nonpregnant women.

Independent risk factors for cesarean section among women with thrombophilia

OBJECTIVE To determine the prevalence of cesarean section (CS) in pregnant women with a diagnosis of thrombophilia and to identify risk factors for CS.

STUDY DESIGN

The women were recognized by an ICD-9 code from a computerized database. Maternal records were reviewed between the years 2000 and 2005. Pregnancy characteristics of 86 women with thrombophilia were compared according to the mode of delivery: CS (n = 18) versus vaginal delivery (n = 68).

RESULTS

The prevalence of CS in the study population was 21% (18/86). Women with CS had a lower gestational age at delivery (P = 0.019), lower birth weight (P = 0.048), higher incidence of the following: preterm delivery (P < 0.001), gestational hypertension (P = 0.028), intrauterine growth retardation/antepartum death/placental abruption (P = 0.065) and non-reassuring fetal heart rate (NRFHR) monitoring (P < 0.001) compared to those with vaginal delivery. In a multiple logistic regression analysis only NRFHR monitoring, birth weight and malpresentation remained statistically significant.

CONCLUSION

CS in women with thrombophilia are associated with common obstetrical causes rather than specific thrombophilia dependent factors.

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.

Antithrombotic therapy and pregnancy: consensus report and recommendations for prevention and treatment of venous thromboembolism and adverse pregnancy outcomes

Venous thromboembolism and adverse pregnancy outcomes are potential complications of pregnancy. Numerous studies have evaluated both the risk factors for and the prevention and management of these outcomes in pregnant patients. This consensus group was convened to provide concise recommendations, based on the currently available literature, regarding the use of antithrombotic therapy in pregnant patients at risk for venous thromboembolic events and adverse pregnancy outcomes.

Placental histopathologic features in patients with thrombophilic mutations

The purpose of this article is to review the histopathologic findings in the placenta of women with a known thrombophilic mutation. The findings range from normal to severe pathologic features including decidual vasculopathy, placental infarctions, syncytial knotting, maternal floor infarction, fetal thrombotic vasculopathy, vasculitis, and chronic villitis. They are, however, not pathognomonic of thrombophilic states, nor are necessarily markers of perinatal damage. The prospective evaluation of cases with known thrombophilic mutations and the application of tissue microarray examination of the placenta may allow identification of major histopathologic features and molecular parameters associated with maternal and/or fetal thrombophilic states. This may assist clinicians in their consultation with patients and optimize management in future pregnancies.

Prise en charge de la mort in utero : quel bilan proposer?

OBJECTIVE

To assess the value of para-clinical exams prescribed in case of in utero foetal death, to result in the establishment of a new algorithm of diagnostic tests.

MATERIALS AND METHODS

A retrospective analysis on a series of 106 stillbirths gathered between September 1989 and December 1998 in the obstetrical and gynaecological department of the Lausanne University Hospital which is a tertiary centre. Stillbirth was defined as foetal death occurring as from the date of foetal viability. Thus, only pregnancies from 24 weeks and onwards were included in this series. We excluded all stillbirths occurring during medical termination of pregnancy and cases with incomplete data files. The Fretts' classification was used. The different exams asked by the physician were screened and we analysed their pertinence to determine the aetiological diagnosis for each case. The search for significant risk factors was also taken into account. We compared our management of in utero foetal death with data from the literature to propose a new algorithm.

RESULTS

The aetiology of in utero foetal death could be attributed in ninety percent of the cases. The principal causes were in utero growth retardation (19.8%), foetal congenital and chromosomal anomalies (18.9%), infections (15.1%), placental abruption (7.5%), preeclampsia (5.6%), maternal diabetes (3.8%). The remaining 18.9% are divided in to miscellaneous causes. In 10.4% of the cases we could not find any explanation to the death of the foetus. The exams that yielded the most information when done were: foetal autopsy which was abnormal in 92.7%, placental investigation which was abnormal in 93% and the babygramme (X-ray of the foetal skeleton) which was abnormal in 53%. Maternal serology for infections was informative in 6.6% of the cases.

CONCLUSION

We present here a protocol for the diagnostic management of stillbirth which is differentiated according to the circumstances surrounding the event. This should prove useful to reduce superfluous tests.

The relationship between thrombophilic mutations and preeclampsia: a prospective case-control study

BACKGROUND

Preeclampsia and its association with thrombophilia remain controversial, due to inconsistent results in different studies, which include different ethnic groups, selection criteria, and patient numbers. The aim of this study was to determine the relationship between thrombophilia and preeclamptic patients in our region.

METHODS

In a prospective case-control study, we compared 100 consecutive women with preeclampsia and eclampsia (group 1) with 100 normal pregnant women (group 2). All women were tested two months after delivery for mutations of factor V Leiden, methylenetetrahydrofolate reductase (MTHFR), and prothrombin gene mutation as well as for deficiencies of protein C, protein S, and antithrombin III.

RESULTS

A thrombophilic mutation was found in 42 (42%) and 28 (28%) women in group 1 and group 2, respectively (P=0.27, OR 1.5, 95%CI 1.0-2.2). The incidence of Factor V Leiden mutation (heterozygous), prothrombin mutation (heterozygous), prothrombin mutation (homozygous), MTHFR mutation (homozygous) was not statistically significant in group 1 compared with group 2 (P>0.05). Also, deficiencies of protein S, protein C, and antithrombin III were not statistically significant in group 1 compared with group 2 (P>0.05).

CONCLUSION

There was no difference in thrombophilic mutations between preeclamptic patients and normal pregnant women in our region. Therefore, we suggest that preeclamptic patients should not be tested for thrombophilia.

Etiology and prevention of stillbirth

OBJECTIVE

This is a systematic review of the literature on the causes of stillbirth and clinical opinion regarding strategies for its prevention.

STUDY DESIGN

We reviewed the causes of stillbirth by performing a Medline search limited to articles in English published in core clinical journals from January 1, 1995, to January 1, 2005. Articles before this date were included if they added historical information relevant to the topic. A total of 1445 articles obtained, 113 were the basis of this review and chosen based on the criterion that stillbirth or fetal death was central to the article.

RESULTS

Fifteen risk factors for stillbirths were identified and the prevalence of these conditions and associated risks are presented The most prevalent risk factors for stillbirth are prepregnancy obesity, socioeconomic factors, and advanced maternal age. Biologic markers associated with increased stillbirth risk are also reviewed, and strategies for its prevention identified.

CONCLUSION

Identification of risk factors for stillbirth assists the clinician in performing a risk assessment for each patient. Unexplained stillbirths and stillbirths related to growth restriction are the 2 categories of death that contribute the most to late fetal losses. Late pregnancy is associated with an increasing risk of stillbirth, and clinicians should have a low threshold to evaluate fetal growth. The value of antepartum testing is related to the underlying risk of stillbirth and, although the strategy of antepartum testing in patients with increased risk will decrease the risk of late fetal loss, it is of necessity associated with higher intervention rates.

Inherited thrombophilias and adverse pregnancy outcome: screening and management

Inherited thrombophilias are a heterogenous group of conditions which have been implicated in a variety of pregnancy complications. Evidence is mounting that implicates these inherited disorders in a range of pregnancy outcomes, including recurrent miscarriage, late fetal loss, preeclampsia, abruptio placentae, and intrauterine growth restriction. The most commonly identified inherited thrombophilias consist of Factor V Leiden and the prothrombin gene mutation G20210A. Rarer inherited thrombophilic conditions include deficiencies of protein S, C and antithrombin. More recently, deficiency of protein Z has been linked to pregnancy complications, including preterm delivery. Clinical manifestations often are associated with the presence of more than one inherited thrombophilia, consistent with their multigenic nature. Some, but not all, studies investigating the use of heparin to prevent adverse pregnancy outcome have demonstrated a benefit. However, an adequate randomized trial is required to definitively determine whether heparin anticoagulation is the best prevention option in patients who harbor one or more inherited thrombophilias and are at risk for adverse pregnancy outcome. This review will summarize the association of thrombophilic conditions and obstetrical complications.

Absence of association of inherited thrombophilia with unexplained third-trimester intrauterine fetal death

OBJECTIVE

The purpose of this study was to investigate the alleged association between thrombophilia and unexplained third-trimester stillbirth.

STUDY DESIGN

Case subjects were 37 women with a history of a third-trimester unexplained stillbirth. Control subjects were 46 volunteers, group-matched for ethnic origin, with no history of stillbirth, recurrent fetal loss, or thromboembolism. The pathology report of 34/37 placentas of case subjects was reviewed.

RESULTS

The prevalence of at least 1 inherited thrombophilia among case subjects was 37.8% compared with 41.3% among control subjects. (OR = 0.87; 95%CI, 0.32-2.29). There was no significant difference between the groups with respect to the prevalence of any single inherited thrombophilia. There was, however, a significantly higher prevalence of antiphospholipid antibodies among case subjects compared with control subjects: 47.2% vs 8.7%, respectively (OR = 9.4; 95%CI, 2.5-42.3). No significant difference was noted in the prevalence of thrombopilia among subjects with or without placental infarcts.

CONCLUSION

We did not find an association between unexplained third-trimester intrauterine fetal death and inherited thrombophilia; however, we did find such an association with antiphospholipid antibodies.

Thrombophilies et pathologies vasculaires placentaires. Revue de la littérature

PURPOSE

Hereditary thrombophilia as antiphospholipid syndrome (APS) may represent a new risk factor for placental vascular diseases.

CURRENT KNOWLEDGE AND KEY POINTS

General screening for biological abnormalities related to thrombophilia is poorly associated with placental vascular diseases and therefore, may be unwarranted. Women with an history of thrombotic diseases may be at risk for late fetal loss or preeclampsia. Adverse obstetric outcomes are particularly high despite anticoagulation regimens in patients with APS. A high frequency for biological abnormalities related to thrombophilia was detected in pregnancies complicated by late fetal loss in comparison with controls. However, no beneficial strategy prevention was clearly reported and therefore, a selective testing was actually debated for these patients.

FUTURE PROSPECTS AND PROJECTS

Searching for acceptable treatment alternatives in patients with APS in order to reduce the high rate for pregnancy complications which may be persistent despite anticoagulation regimens. To determine by controlled studies the role for a prophylactic low molecular weight heparin regimens in patients with haemostatic abnormalities and previous pregnancy complications.

Screening and management of inherited thrombophilias in the setting of adverse pregnancy outcome

Inherited thrombophilic conditions are associated with adverse pregnancy outcomes, including severe pre-eclampsia, fetal loss, abruptio placentae, and intauterine growth restriction. Although the prevalence of these complications is approximately 8% in the general population, their presence is associated with a significantly increased recurrence risk. Thrombophilic conditions most strongly associated with adverse pregnancy outcome include factor V Leiden, prothrombin gene mutation, and deficiencies of protein S, protein C, and antithrombin. Other thrombophilic conditions, such as protein Z deficiency, also appear to be associated with an increased risk of pregnancy complications. Antenatal administration of heparin to prevent pregnancy complications has shown promise in small studies, but a randomized, placebo-controlled trial is necessary to determine whether heparin administration is beneficial in preventing adverse pregnancy outcome.

The common prothrombotic factors in nulliparous women do not compromise blood flow in the feto-maternal circulation and are not associated with preeclampsia or intrauterine growth restriction

OBJECTIVE

In this study we evaluated the associations between common prothrombotic factors and increased blood flow resistance in the feto-maternal circulation, intrauterine growth restriction, small for gestational age, or preeclampsia.

STUDY DESIGN

A prospective study was conducted in healthy nulliparous women with spontaneous singleton pregnancy. Blood was tested for the common prothrombotic factors, i.e., factor V Leiden, factor II G20210A, methylenetetrahydrofolate reductase C677T, anticardiolipin, and lupus anticoagulant. Blood flow resistance in the uterine, placental, and umbilical arteries were assessed by multigate Doppler and compared between women with and without prothrombotic factors. The maternal, fetal, and neonatal clinical courses were also compared among these subgroups.

RESULTS

Prothrombotic factors were detected in 191 of 637 (30%) subjects. No significant difference in resistance to blood flow in the feto-maternal unit was discernible between women with and without prothrombotic factors. Pregnancy-induced hypertension or preeclampsia occurred in 10 of 191 (5.2%) and in 19 of 446 (4.3%) of women with and without a prothrombotic factor respectively ( P = .59). Intrauterine growth restriction was detected at 31 weeks in 13 of 164 (7.9%) and in 42 of 377 (11.1%) fetuses of women with and without a prothrombotic factor ( P = .26), and small for gestational age at delivery was observed in 19 of 187 (10.2%) and in 41 of 413 (9.9%) of mothers with and without prothrombotic markers, respectively.

CONCLUSION

The presence of prothrombotic factors in healthy nulliparous women does not compromise blood flow in the feto-maternal unit, nor is it associated with preeclampsia, intrauterine growth restriction, or small for gestational age .

Genetic thrombophilia

The genetic thrombophilias are an important cause of venous thrombotic events. Much has been learned about the natural history of these disorders, their genetics, and, to a lesser degree, their treatment. This article provides an overview of the genetics of thrombophilia. Specific information on the factor V Leiden mutation;the prothrombin G20210A mutation; and protein C, proteinS, and antithrombin deficiency is reviewed. Current testing and treatment options for the genetic thrombophilias also are discussed.

Thrombophilia and pregnancy complications

OBJECTIVE

This systematic review examines the strength of the association between thrombophilia and recurrent pregnancy loss and other serious obstetric complications. Study design Electronic databases and manual bibliography searches were used to identify studies evaluating the association between thrombophilia and pregnancy loss, preeclampsia, fetal growth retardation, and placental abruption.

RESULTS

Thrombophilic disorders are associated with an increased risk of fetal loss in the majority of case control and cohort studies. The risk is increased throughout pregnancy, but may be higher in the second and third trimester. The common pathologic finding of placental infarction suggests unexplained fetal loss may result from uteroplacental insufficiency and thrombosis. Thrombophilic disorders are not consistently associated with preeclampsia, fetal growth retardation, or placental abruption. Preliminary data suggest prophylactic anticoagulation may improve outcome in thrombophilic women with unexplained recurrent fetal loss.

CONCLUSION

Women with thrombophilia have an increased risk of pregnancy loss and possibly other serious obstetric complications, although definition of the magnitude of risk will require prospective longitudinal studies. Preliminary data suggesting prophylactic anticoagulation may improve gestational outcome provide a rationale for prospective randomized trials in thrombophilic women with unexplained recurrent fetal loss.

Thrombophilia and stillbirth: possible connection by intrauterine growth restriction

OBJECTIVE

To define the association between thrombophilia and unexplained stillbirth.

DESIGN

A case-control study.

SETTING

Obstetric department in a university affiliated hospital (Ha'Emek Medical Center, Afula).

POPULATION

A total of 53 women who delivered stillborns between March 1998 and June 2002 and 59 women with unremarkable obstetric history who delivered at the same period.

METHODS

Presence of genetic and acquired markers of thrombophilia was investigated.

MAIN OUTCOME MEASURE

Presence or absence of thrombophilia.

RESULTS

Thrombophilia was found in 34% of the women who delivered stillborns and in 20% of the 59 women with normal pregnancies (non-significant). However, significantly higher prevalence of thrombophilia (73%) was found in women who delivered small for gestational age stillborns compared with women who delivered normal birthweight stillborns (73%vs 18.4%, P < 0.0001).

CONCLUSIONS

There is no association between thrombophilia and stillbirth, overall. However, there is a clear association between thrombophilia and stillbirth of extremely growth restricted infants.

Prothrombin gene variants in non-Caucasians with fetal loss and intrauterine growth retardation

Thrombotic predisposition may affect pregnancy outcome, but in non-Caucasians the contributing genetic factors are poorly characterized. Two recently identified prothrombin gene mutations (20209C>T and 20221C>T) have been observed in non-Caucasian patients with thrombosis. The mutations are located near the commonly identified variant 20210G>A and have not been reported in Caucasian patients. The authors report a novel connection with pregnancy complications. The identification of sequence variants other than 20210G>A in the 3'-untranslated region of the prothrombin gene suggests that additional nucleotide substitutions may contribute to the development of thrombotic events and adverse pregnancy outcomes, especially in less well-characterized populations.

Sex and gender issues and venous thromboembolism

At least 250,000 episodes of VTE leading to hospitalization or death are estimated to occur in the United States each year. A number of clinical and demographic risk factors for VTE are recognized,with the latter including both age and race. Overall,the incidence of VTE does not appear to vary significantly by sex, as evidenced by a lack of consistency in the magnitude and even direction of effect of sex in a variety of epidemiologic studies of varying design. Several studies have shown a higher incidence among women than men during childbearing age. The issue of a gender effect on the natural history of VTE has not been well studied. The main influence of gender on VTE is the relationship between female gender and several well-recognized clinical risk factors for VTE:oral contraceptive use, hormone replacement therapy, estrogen receptor modulator therapy, and pregnancy. Hormonal therapies are associated with a twofold to threefold increase in VTE incidence. Risk is higher with some formulations than others, during initial use, and among women who are obese, smoke, or have one of several forms of heritable thrombophilia. The pregnant state is associated with a threefold to fivefold increase in VTE risk, and thromboembolism is a major cause of peripartum death. Heritable thrombophilias are also important co-determinants of VTE risk in pregnancy. The mechanisms through which pregnancy and hormonal therapies increase VTE risk have not been definitively established, but hormonal effects on levels of coagulation and anticoagulation factors likely play a role. Venous compression and venous injury also contribute to increased risk during pregnancy and the puerperium. Approaches to diagnosis of VTE in the pregnant woman are largely the same as in the nonpregnant patient, but special treatment considerations do apply. Warfarin is embryopathic, particularly between the 6th and 12th weeks of pregnancy, and should be avoided in favor or heparin or low-molecular weight heparin when treatment of the pregnant woman is necessary. Guidelines have been published to assist the clinician in decision making about prophylaxis of pregnant women at increased risk or pregnancy-related or post-partum VTE.

Placental pathology in fetal thrombophilia

The aim of this study was to test the hypothesis that placental vascular lesions of the fetal circulation are caused by fetal thrombophilic mutations. The study included 64 newborns of women with one or more of the following pregnancy complications: preeclampsia, placental abruption, and intrauterine growth restriction. The most prevalent inherited thrombophilias--factor V Leiden, factor II (prothrombin) G20210A, and homozygosity for methyltetrahydrofolate reductase C677T--were examined in maternal blood and fetal umbilical cord blood. One pathologist reviewed all of the slides for fetal vascular lesions. Associations between fetal thrombotic vasculopathy and fetal thrombophilia were tested for using Fisher's exact test; Z scores and gestational age were compared using the Student t-test. Fetal thrombophilic mutations were diagnosed in 19 of 64 newborns, 15 of whom had coexistent maternal thrombophilia. There was no statistical difference in the prevalence of thrombotic lesions of the fetal circulation between newborns with and without thrombophilia. The combination of maternal and fetal thrombophilia was also not associated with increased fetal vascular lesions. The results indicate that fetal thrombophilia alone, even in the context of maternal underperfusion, is not associated with fetal vascular lesions of the placenta, although it may represent an underlying risk factor for lesions triggered by other process(es).

Methylenetetrahydrofolate reductase and transcobalamin genetic polymorphisms in human spontaneous abortion: biological and clinical implications

The pathogenesis of human spontaneous abortion involves a complex interaction of several genetic and environmental factors. The firm association between increased homocysteine concentration and neural tube defects (NTD) has led to the hypothesis that high concentrations of homocysteine might be embryotoxic and lead to decreased fetal viability. There are several genetic polymorphisms that are associated with defects in folate- and vitamin B12-dependent homocysteine metabolism. The methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C polymorphisms cause elevated homocysteine concentration and are associated with an increased risk of NTD. Additionally, low concentration of vitamin B12 (cobalamin) or transcobalamin that delivers vitamin B12 to the cells of the body leads to hyperhomocysteinemia and is associated with NTD. This effect involves the transcobalamin (TC) 776C>G polymorphism. Importantly, the biochemical consequences of these polymorphisms can be modified by folate and vitamin B12 supplementation. In this review, I focus on recent studies on the role of hyperhomocysteinemia-associated polymorphisms in the pathogenesis of human spontaneous abortion and discuss the possibility that periconceptional supplementation with folate and vitamin B12 might lower the incidence of miscarriage in women planning a pregnancy.

Polycystic ovary syndrome, the G1691A factor V Leiden mutation, and plasminogen activator inhibitor activity: associations with recurrent pregnancy loss

Our specific aim was to assess associations of thrombophilia, hypofibrinolysis, and polycystic ovary syndrome (PCOS) with recurrent pregnancy loss (RPL) (>/=3 consecutive pregnancy losses < 20 weeks gestation). Prospective studies were performed in 33 Caucasian women referred for diagnosis and treatment of PCOS who were subsequently found to have RPL and in 16 Caucasian women referred for diagnosis and treatment of RPL, who did not have PCOS. Cases (PCOS-RPL, RPL without PCOS) were compared with controls (116 healthy Caucasian females) for the G1691A Factor V Leiden, G20210A prothrombin, C677T methylenetetrahydrofolate reductase (MTHFR), plasminogen activator inhibitor 4G/5G, and platelet glycoprotein PL A1A2 gene mutations. Cases were compared with controls (44 healthy adult Caucasian females) for serologic coagulation tests including homocysteine, proteins C, S, free S, antithrombin III, anticardiolipin antibodies IgG and IgM, dilute Russel's viper venom time, activated partial thromboplastin time, Factor VIII, Factor XI, lipoprotein (Lp)(a), and plasminogen activator inhibitor activity (PAI-Fx). The 33 Caucasian women with PCOS subsequently found to have RPL were 10% of a cohort of 322 Caucasian women who had >/= 1 previous pregnancy and had been referred for diagnosis and therapy of PCOS over a 4.3-year period. The Factor V Leiden G1691 mutation was present in 6 of 33 women (18%) with PCOS-RPL and in 3 of 16 women with RPL without PCOS (19%) versus 2 of 116 (1.7%) female controls, Fisher's P (p(f)) =.0016, p(f) =.013. The 33 PCOS-RPL cases also differed from the 44 female controls for high PAI-Fx (>21.1 U/mL), 38% versus 8%, p(f) =. 004. The thrombophilic G1691A Factor V Leiden mutation is associated with RPL in women with and without PCOS; hypofibrinolysis (high PAI-Fx) is also associated with RPL in women with PCOS.

Thrombophilia and pregnancy

Pregnancy is hypercoagulable state. The field of thrombophilia; the tendency to thrombosis, has been developed rapidly and has been linked to many aspects of pregnancy. It is recently that severe pregnancy complications such as severe preeclampsia intrauterine growth retardation abruptio placentae and stillbirth has been shown to be associated with thrombophilia. Recurrent miscarriage and has also been associated with thrombophilia. Finally, thromboembolism in pregnancy as in the non-pregnant state is linked to thrombophilia. In this review all aspects of thrombophilia in pregnancy are discussed, and also all prophylactic and therapeutic implications.

Unexpected fetal death during pregnancy--a problem of unrecognized fetal disorders during antenatal care?

OBJECTIVE

To investigate the causes of ante partum fetal death (APFD) and to evaluate the diagnostic methods for prevention.

MATERIAL AND METHODS

A population-based retrospective study was conducted in 293091 deliveries from 1996 to 2000 in the State of Hesse, Germany. The investigations focus on mortality of infants during pregnancy, separated between singletons of 37-42 weeks (n=361) and 23-36 weeks (n=550), and multiple births (n=76). In 44 cases, the gestational age was unknown and in 19 cases lower than 23 weeks or greater than 43 weeks. In total 1006 cases remained and were subject for evaluation.

RESULTS

Perinatal mortality (PM) was 0.56%. APFD occurred in 1050 cases (0.3%), i.e. 63.5% of PM. Risk factors from the medical history during pregnancy could be identified in 515 cases (51.2%). Significant risk factors were social burden (odds ratio (OR) 58.3), diabetes mellitus (OR 5.4) and gestational diabetes (OR 2.1), psychological burden (OR 4.8), proteinuria (OR 2.8), maternal age (OR 1.7) and maternal smoking, depending on the number of cigarettes. The risk factors show a difference in significance, if related to the gestational age and multiple pregnancies. The contribution of malformations to APFD was 7.8%. There was however a number of unexpected fetal deaths with unidentified risk factors: n=415 (41.3%). In this group, fetal growth restriction was observed in 38.1%. Compared to control, APFD was three to five times higher in fetal growth retardation below the 10th percentile. Fetal death was closely related to fetal surveillance, i.e. the number of antenatal visits, ultrasound measurements, and fetal heart rate monitoring.

CONCLUSION

Fetal ante partum fetal death can be reduced at least by 50%, if the available methods for fetal surveillance are employed aiming to detect indications of fetal oxygen deprivation at an early stage.

[Heterozygous prothrombin gene mutation G20210A and associated diseases]

PURPOSE

Prothrombin gene mutation G20210A (factor II) is, in frequency, the second genetic polymorphism involved in venous thrombosis. We report a retrospective studies on 38 patients issued from our medical department, all heterozygous for the factor II mutation and a literature review.

METHODS

We have studied 38 patients, all heterozygous for the factor II mutation, selected through a population of 516 tested patients issued from our medical department from 1997 to 2002. The research was performed face with history of thrombotic or obstetrical events, angiopathy or familial screening.

RESULTS

Twenty out of thirty-eight patients have at least one episode of venous thrombosis: superficial thromboses, deep thromboses and/or pulmonary embolism. One case of cerebral thrombophlebitis is observed. Venous thrombotic risk factors are associated in 12 cases (60%). Four out of thirty-eight patients have one episode of arterial thrombosis: cardiovascular, peripheral or cerebral. Arterial thrombotic risk factors are associated in all cases. Median age of the first venous thrombosis is earlier than the one of arterial thrombosis (39.11 versus 49.25 years).

CONCLUSION

Our studies confirms the interest to search the prothrombin gene mutation when faced with a venous thrombotic event (deep vein thrombosis and/or pulmonary embolism) with or without acquired risk factors. Its involvement in thrombotic arterial disease is still a matter of debate. Data concerning its involvement in systemic diseases and angiopathies (thromboangeitis obliterans, Raynaud's phenomenon and migraine) are still needed. Mechanisms of thromboses could be an increase of prothrombin plasma level with high thrombin synthesis.

Risk factors for unexplained antepartum fetal death in Norway 1967-1998

OBJECTIVE

To relate unexplained antepartum fetal death with maternal and fetal characteristics in order to identify risk factors.

DESIGN

Population-based study based on records of 1,676,160 singleton births with gestational age > or =28 weeks. Unexplained antepartum fetal death was defined as fetal death before labour without known fetal, placental, or maternal pathology.

RESULTS

Although unexplained fetal mortality in general declined from 2.4 per 1000 births in 1967-1976 to 1.6 in 1977-1998, the proportion among all fetal deaths increased from 30% to 43% during the same period of observation. Unexplained fetal death occurred later in gestation than explained. From 39 weeks of gestation, the risk increased progressively to 50/10,000 in women aged > or =35 years and <10/10,000 in women <25 years. In birth order > or =5, the risk was particularly high after 39 weeks of gestation. For birth weight percentile 2.5-9.9 and > or =97.5, unexplained fetal death was four and three times more likely to occur, respectively. We found an additive effect of maternal age and birth weight percentile 2.5-9.9. Women with less than 10 years education had higher risk than women with 13 years or more (OR=1.6). Weaker associations were observed with female gender, unmarried mothers, and winter season.

CONCLUSIONS

Unexplained antepartum fetal death occurred later in gestation than explained and was associated with high maternal age, multiparity, low education, and moderately low and high birth weight percentile. The increased risk in post-term pregnancies and the additive effect of maternal age and birth weight percentile 2.5-9.9 suggests that older women would benefit from monitoring of fetal growth.