The effect of thrombophylaxis on pregnancy outcome in patients with recurrent pregnancy loss associated with factor V Leiden mutation

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

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

Effects of anticoagulant therapy on pregnancy outcomes in patients with thrombophilia and previous poor obstetric history

This study investigates the effects of anticoagulant therapy on pregnancy outcomes in 204 patients with thrombophilia and previous poor obstetric outcomes. Patients with poor obstetric history (pre-eclampsia, intrauterine growth retardation, fetal death, placental abruption, recurrent pregnancy loss) and having hereditary thrombophilia were included in this study. Poor obstetric outcomes were observed more frequently in patients who had not taken anticogulant therapy compared with treated group. Live birth rate, gestational age at birth and Apgar scores were significantly higher in the treated group when compared with the untreated group. There were no significant differences in terms of birthweight, mode of delivery and admission rates to the neonatal intensive care unit (NICU). Low-molecular-weight heparin (LMWH) plus acetylsalicylic acid (ASA) had higher gestational age at birth, Apgar scores, live birth rate and a lower abortion rates when compared with controls; in contrast, no significant difference was observed in terms of birthweight, mode of delivery, obstetric complications and admission rates to NICU. There were no significant differences between control group and both LMWH only and ASA only groups in terms of gestational age at birth, Apgar scores, birthweight, mode of delivery, obstetric complications and admission rates to NICU. Only LMWH group had higher live birth rate as compared with control group. The use of only ASA did not seem to affect the perinatal complication rates and outcomes. In conclusion, anticoagulant therapy with both LMWH and ASA seems to provide better obstetric outcomes in pregnant women with thrombophilia and previous poor obstetric outcomes.

Factor V Leiden mutation in women with early recurrent pregnancy loss: a meta-analysis and systematic review of the causal association

BACKGROUND

Recently, the interest has focused on the increased prevalence of thrombophilic defects in women with gestational complications.

OBJECTIVE

To explore whether women with early recurrent pregnancy loss (RPL) are at increased risk of being carriers of the Factor V Leiden (FVL) mutation compared to those who have a normal reproductive history.

METHODS

A manual and electronic literature search was undertaken to identify studies with a case-control population of women with two or more first trimester RPLs of undetermined origin and age- and ethnicity-matched control group with normal reproductive history and at least one full-term delivery. Both groups were screened for FVL mutation. A quality assessment was performed according to the pre-established validity criteria and using the Cochrane handbook guidelines for observational studies. The combinability of studies was assessed by clinical and statistical methods (Breslow-Day's test of homogeneity). Quantitative data were abstracted with regard to the prevalence of FVL mutation in the case and control group, and 2 × 2 tables were created. The ratio comparing the odds of FVL mutation in women with early RPL with the odds of FVL mutation in women with normal reproductive outcome was calculated with its 95% confidence interval (CI) by Mantel-Haenszel method.

RESULTS

Nine studies met the inclusion criteria and were selected for review. A total of 2,147 women were screened for the FVL mutation, 1,305 women with early RPL, and 842 women with no gestational complications. Women with early RPL had indeed a statistically significantly increased carrier frequency of FVL mutation, the common OR being 1.68 (95% CI: 1.16-2.44).

CONCLUSION

FVL carrier state may increase the susceptibility for early RPL. Testing for FVL mutation should be considered in women with unexplained early RPL and thrombophylaxis has been suggested in women with unexplained RPL associated with FVL mutation.

Aspirin and/or heparin for women with unexplained recurrent miscarriage with or without inherited thrombophilia

BACKGROUND

Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the chance of live birth in subsequent pregnancies in women with unexplained recurrent miscarriage, with or without inherited thrombophilia.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2013) and scanned bibliographies of all located articles for any unidentified articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on live birth in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia were eligible. Interventions included aspirin, unfractionated heparin (UFH), and low molecular weight heparin (LMWH) for the prevention of miscarriage. One treatment could be compared with another or with no-treatment (or placebo).

DATA COLLECTION AND ANALYSIS

Two review authors (PJ and SK) assessed the studies for inclusion in the review and extracted the data. If necessary they contacted study authors for more information. We double checked the data.

MAIN RESULTS

Nine studies, including data of 1228 women, were included in the review evaluating the effect of either LMWH (enoxaparin or nadroparin in varying doses) or aspirin or a combination of both, on the chance of live birth in women with recurrent miscarriage, with or without inherited thrombophilia. Studies were heterogeneous with regard to study design and treatment regimen and three studies were considered to be at high risk of bias. Two of these three studies at high risk of bias showed a benefit of one treatment over the other, but in sensitivity analyses (in which studies at high risk of bias were excluded) anticoagulants did not have a beneficial effect on live birth, regardless of which anticoagulant was evaluated (risk ratio (RR) for live birth in women who received aspirin compared to placebo 0.94, (95% confidence interval (CI) 0.80 to 1.11, n = 256), in women who received LMWH compared to aspirin RR 1.08 (95% CI 0.93 to 1.26, n = 239), and in women who received LMWH and aspirin compared to no-treatment RR 1.01 (95% CI 0.87 to 1.16) n = 322).Obstetric complications such as preterm delivery, pre-eclampsia, intrauterine growth restriction and congenital malformations were not significantly affected by any treatment regimen. In included studies, aspirin did not increase the risk of bleeding, but treatment with LWMH and aspirin increased the risk of bleeding significantly in one study. Local skin reactions (pain, itching, swelling) to injection of LMWH were reported in almost 40% of patients in the same study.

AUTHORS' CONCLUSIONS

There is a limited number of studies on the efficacy and safety of aspirin and heparin in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia. Of the nine reviewed studies quality varied, different treatments were studied and of the studies at low risk of bias only one was placebo-controlled. No beneficial effect of anticoagulants in studies at low risk of bias was found. Therefore, this review does not support the use of anticoagulants in women with unexplained recurrent miscarriage. The effect of anticoagulants in women with unexplained recurrent miscarriage and inherited thrombophilia needs to be assessed in further randomised controlled trials; at present there is no evidence of a beneficial effect.

Aspirin and/or heparin for women with unexplained recurrent miscarriage with or without inherited thrombophilia

BACKGROUND

Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the chance of live birth in subsequent pregnancies in women with unexplained recurrent miscarriage, with or without inherited thrombophilia.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (1 October 2013) and scanned bibliographies of all located articles for any unidentified articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on live birth in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia were eligible. Interventions included aspirin, unfractionated heparin (UFH), and low molecular weight heparin (LMWH) for the prevention of miscarriage. One treatment could be compared with another or with no-treatment (or placebo).

DATA COLLECTION AND ANALYSIS

Two review authors (PJ and SK) assessed the studies for inclusion in the review and extracted the data. If necessary they contacted study authors for more information. We double checked the data.

MAIN RESULTS

Nine studies, including data of 1228 women, were included in the review evaluating the effect of either LMWH (enoxaparin or nadroparin in varying doses) or aspirin or a combination of both, on the chance of live birth in women with recurrent miscarriage, with or without inherited thrombophilia. Studies were heterogeneous with regard to study design and treatment regimen and three studies were considered to be at high risk of bias. Two of these three studies at high risk of bias showed a benefit of one treatment over the other, but in sensitivity analyses (in which studies at high risk of bias were excluded) anticoagulants did not have a beneficial effect on live birth, regardless of which anticoagulant was evaluated (risk ratio (RR) for live birth in women who received aspirin compared to placebo 0.94, (95% confidence interval (CI) 0.80 to 1.11, n = 256), in women who received LMWH compared to aspirin RR 1.08 (95% CI 0.93 to 1.26, n = 239), and in women who received LMWH and aspirin compared to no-treatment RR 1.01 (95% CI 0.87 to 1.16) n = 322).Obstetric complications such as preterm delivery, pre-eclampsia, intrauterine growth restriction and congenital malformations were not significantly affected by any treatment regimen. In included studies, aspirin did not increase the risk of bleeding, but treatment with LWMH and aspirin increased the risk of bleeding significantly in one study. Local skin reactions (pain, itching, swelling) to injection of LMWH were reported in almost 40% of patients in the same study.

AUTHORS' CONCLUSIONS

There is a limited number of studies on the efficacy and safety of aspirin and heparin in women with a history of at least two unexplained miscarriages with or without inherited thrombophilia. Of the nine reviewed studies quality varied, different treatments were studied and of the studies at low risk of bias only one was placebo-controlled. No beneficial effect of anticoagulants in studies at low risk of bias was found. Therefore, this review does not support the use of anticoagulants in women with unexplained recurrent miscarriage. The effect of anticoagulants in women with unexplained recurrent miscarriage and inherited thrombophilia needs to be assessed in further randomised controlled trials; at present there is no evidence of a beneficial effect.

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.

Anticoagulants to prevent placenta-mediated pregnancy complications: a review of current evidence

PURPOSE OF REVIEW

Placenta-mediated pregnancy complications are relatively common and are associated with significant morbidity and mortality. Although anticoagulants are increasingly being used to prevent these complications, the evidence supporting their use is limited. This article will focus on reviewing the current evidence base for the use of anticoagulants to prevent placenta-mediated pregnancy complications in women with or without identifiable thrombophilia.

RECENT FINDINGS

Controversy exists whether inherited or acquired thrombophilias cause placenta-mediated complications. Small randomized studies with methodological limitations suggest that antepartum anticoagulant prophylaxis will reduce pregnancy loss in women with both acquired and inherited thrombophilia and prior pregnancy loss. There are no published randomized controlled trials examining anticoagulant prophylaxis in thrombophilic women with prior preeclampsia, intrauterine growth restriction or placental abruption. More recently, the benefit of antepartum anticoagulant prophylaxis in women without thrombophilia with prior placenta-mediated pregnancy complications has been suggested in a small pilot randomized trial.

SUMMARY

Overall, although antepartum anticoagulant prophylaxis has the potential to reduce placenta-mediated pregnancy complications in women with and without identifiable thrombophilia, the data generated by these trials are methodologically limited and inadequate. Hence, we conclude that further trials are required prior to adopting the use of antepartum anticoagulant prophylaxis to prevent placenta-mediated pregnancy complications in routine clinical practice.

Paternal thrombophilic gene mutations are not associated with recurrent miscarriage

PROBLEM

Recurrent miscarriage (RM) affects 1-3% of couples. So far, diagnostic procedures are performed only in female patients. However, the main part of the placentary perfusion is encoded by both the maternal and the paternal genome.

METHOD OF STUDY

In this case-control study, German couples with two (n = 49) or three and more RM (n = 102) and 157 German control couples were analyzed for the factor V-Leiden 169 1G > A mutation (FVL), the prothrombin (PT) 202 10G > A substitution, and the 677C > T replacement in the 5, 10-methylenetetrahydrofolate reductase (MTHFR) gene.

RESULTS

No significant differences in the prevalence of the FVL, PT or MTHFR mutation were observed in male partners of RM patients and in control men [RM/control: FVL heterozygous 13/151 (8.6%): 14/157 (8.9%) (P = 0.9); PT heterozygous 2/151 (1.3%): 7/157 (4.5%) (P = 0.097); PT homozygous 0/151: 2/157 (1.3%); MTHFR homozygous 19/151 (12.6%): 18/157 (11.5%) (P = 0.12)]. This was also true for female RM patients. However, miscarriage during the embryonal period (5-10 weeks of gestation) was significantly associated with a maternal heterozygous FVL mutation (P = 0.014).

CONCLUSION

Recurrent miscarriage was not associated with paternal thrombophilia. Men of the control group showed an even higher incidence of the PT and MTHFR mutations. Abortions in the embryonic phase of fetal development were associated with a significantly higher incidence of maternal heterozygosity for FVL.

Use of Heparin in Women With Early and Late Miscarriages With and Without Thrombophilia

Objective: In women with a history of recurrent miscarriage, the risk of miscarriage in a subsequent pregnancy is about 30% to 40%. In patients with thrombophilia, the risk is even higher. Placental thrombosis has been found in women with unexplained recurrent miscarriage independent of thrombophilia. In addition, proinflammatory changes, for example, altered Th1 to Th2 cytokine ratio and complement activation, have been repeatedly demonstrated in these women. Because of the fact that heparin has both anticoagulative and anti-inflammatory effects, the current study evaluated the efficacy of low-molecular-weight heparin (LMWH) in unexplained abortions. Study Design: A total of 164 women with unexplained early and late miscarriages presented in our hemostaseological clinic for thrombophilia screening. For these 164 women, 82 subsequent pregnancies in 79 patients were treated with subcutaneous LMWH independently of thrombophilia. In 54/82 unselected pregnancies, 100 mg aspirin was administered in addition to LMWH. Two patients were excluded due to termination of pregnancy. Results: Overall, 83.8% (67/80) of pregnancies resulted in live births. In 22/79 women (27.8%), thrombophilia markers were positive. Most noteworthy, patients with thrombophilia markers had live births at a similar frequency as patients without those parameters. No severe side effects of LMWH were seen. Conclusions: Our data support the notion that LMWH is efficacious in patients with recurrent abortions and thrombophilia. We demonstrated the same effect of LMWH in women with unexplained abortions without thrombophilia. The potential mechanism of action of LMWH in early and late abortions warrants further study.

Aspirin or anticoagulants for treating recurrent miscarriage in women without antiphospholipid syndrome

BACKGROUND

Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the live-birth rate in subsequent pregnancies in women with either inherited thrombophilia or unexplained recurrent miscarriage.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two miscarriages without apparent causes other than inherited thrombophilia.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 1), MEDLINE (January 1966 to March 2007), and EMBASE (1980 to March 2007). We scanned bibliographies of all located articles for any unidentified articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on the live-birth rate in women with a history of at least two miscarriages (up to 20 weeks of amenorrhoea) without apparent causes other than inherited thrombophilia were eligible. Interventions included aspirin, unfractionated heparin, and low molecular weight heparin for the prevention of miscarriage. One treatment could be compared with another or with placebo.

DATA COLLECTION AND ANALYSIS

Two authors assessed the trials for inclusion in the review and extracted the data. We double checked the data.

MAIN RESULTS

Two studies (189 participants) were included in the review. In one study, 54 pregnant women with recurrent miscarriage (RM) but no detectable anticardiolipin antibodies were randomised to low-dose aspirin or placebo. RM was defined as three or more consecutive miscarriages (occurring before 22 weeks' gestational age (based on last menstrual period)). Similar live-birth rates were observed with aspirin and placebo, both 81% (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.78 to 1.29). In the other study, 107 women with consecutive recurrent miscarriage without any apparent cause and no hereditary thrombophilia were randomised between enoxaparin and aspirin. Here RM was stated as three or more consecutive first trimester miscarriages or at least two consecutive second trimester miscarriages. Similar live birth rates were observed with enoxaparin and aspirin, respectively 82% and 84% (RR 0.97, 95% CI 0.81 to 1.16).

AUTHORS' CONCLUSIONS

There is a paucity in studies on the efficacy and safety of aspirin and heparin in women with a history of at least two miscarriages without apparent causes other than inherited thrombophilia. The two reviewed trials studied different treatments and only one study was placebo-controlled. Neither of the studies showed a benefit of one treatment over the other. Therefore, the use of anticoagulants in this setting is not recommended. However, large randomised placebo-controlled trials are still urgently needed.

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.

Multifactorial thrombophilia in a pregnancy: a case report

Thrombophilias are inherited or acquired conditions that predispose individuals to thromboembolism. Thrombophilic disorders increase obstetric complications, such as early pregnancy loss, fetal growth retardation, placental abruption, and preeclampsia. Recurrent pregnancy loss affects 1% to 3% of women of reproductive age, and a large proportion of these losses remain unexplained. Thrombophilic defects were found in 49% to 65% of women with pregnancy complications compared with 18% to 22% of women with normal pregnancies, suggesting a 3- to 8-fold increase in risk. We report a case of a pregnant woman who had a history of recurrent pregnancy losses that was complicated with protein S deficiency, factor V Leiden mutation, methylene tetrahydrofolate reductase mutation, and antiphospholipid syndrome in her pregnancy.

B-Lynch suture after the failure of hypogastric artery ligation to control post-partum hemorrhage due to placenta increta in a patient with the factor V Leiden mutation

Post-partum hemorrhage may be a life-threatening condition. A case of a patient receiving antithrombotic therapy for the factor V Leiden mutation, in whom post-partum hemorrhage had occurred due to placenta increta, is described. In this case, the post-partum hemorrhage did not respond to bilateral hypogastric artery ligation, while the B-Lynch surgical technique was successful in obtaining hemostasis.

Inherited Thrombophilias

Many inherited thrombophilias have been detected and the pathophysiologic insight has increased tremendously during the last decades. Despite, however, the overwhelming observational evidence on the association between inherited thrombophilia and several women's health issues, including VTE, thus far the implications for clinical practice are uncertain. Although there is firm epidemiologic evidence that is helpful in counseling women who have inherited thrombophilia to prevent a first or recurrent VTE, the uncertainty is particularly present for women who have other pregnancy complications, such as recurrent pregnancy loss and pre-eclampsia. For this group, well-designed placebo-controlled trials to assess the harm-benefit ratio are urgently needed.

Inherited Thrombophilia: Treatment during Pregnancy

OBJECTIVE

Inherited thrombophilia is associated with thromboembolic events and/or poor obstetric outcome. We evaluated the pregnancy outcome in women with inherited thrombophilia treated with low-molecular-weight heparin (LMWH).

METHODS

38 thrombophilic women with a history of thromboembolic events and/or poor obstetric outcome were treated during their 39 consecutive pregnancies with LMWH from pregnancy verification until 4-6 weeks in puerperium. A fixed dose of enoxaparin 4,000 IU/day (except 1 case who required nadroparin 0.3 ml/day) was administered in most cases, adopting a higher dose (6,000 IU/day to 6,000 IU twice a day) in those with previous thromboembolic events.

RESULTS

In the treated women, all had a good obstetric outcome, whereas in the previous untreated pregnancies (n = 78), the rate of fetal loss (early and late) was 76.9%, only 12 live infants survived (66.6%). Moreover, birth weight resulted significantly higher in live infants born to treated pregnancies in comparison to that of previous untreated pregnancies (p = 0.009). No maternal thrombosis or major bleeding complications were recorded.

CONCLUSIONS

The treatment with LMWH improved pregnancy outcome resulting effective and safe in thrombophilic women with a history of thromboembolic events and/or poor obstetric outcome.

Effects of enoxaparin on late pregnancy complications and neonatal outcome in women with recurrent pregnancy loss and thrombophilia: results from the Live-Enox study

Women with thrombophilia and a history of recurrent pregnancy loss have poor pregnancy outcomes. Prophylaxis with enoxaparin 40 mg/day or 80 mg/day resulted in favorable gestational and neonatal outcomes.

Anticoagulants for the treatment of recurrent pregnancy loss in women without antiphospholipid syndrome

BACKGROUND

Since hypercoagulability might result in recurrent pregnancy loss, anticoagulant agents could potentially increase the live-birth rate in subsequent pregnancies in women with either inherited thrombophilia or unexplained pregnancy loss.

OBJECTIVES

To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (March 2004), the Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2004), MEDLINE (January 1966 to March 2004), and EMBASE (1980 to March 2004). We scanned bibliographies of all located articles for any unidentified articles.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on the live-birth rate in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias were eligible. Interventions included aspirin, unfractionated heparin, and low molecular weight heparin for the prevention of birth loss. One treatment could be compared with another or with placebo.

DATA COLLECTION AND ANALYSIS

Two authors assessed the trials for inclusion in the review and extracted the data. Data were entered into the Review Manager software and double checked.

MAIN RESULTS

Two studies (242 participants) were included in the review and for both of them data were extracted for the subgroups of women fulfilling the inclusion criteria of the review. In one study, 54 pregnant women with recurrent spontaneous abortion without detectable anticardiolipin antibodies were randomised to low-dose aspirin or placebo. Similar live-birth rates were observed with aspirin and placebo (relative risk (RR) 1.00, 95% confidence interval (CI) 0.78 to 1.29). In another study, a subgroup of 20 women who had had a previous fetal loss after the 20th week and had a thrombophilic defect were randomised to enoxaparin or aspirin. Enoxaparin treatment resulted in an increased live-birth rate, as compared to low-dose aspirin, RR 10.00, 95% CI 1.56 to 64.20).

AUTHORS' CONCLUSIONS

The evidence on the efficacy and safety of thromboprophylaxis with aspirin and heparin in women with a history of at least two spontaneous miscarriages or one later intrauterine fetal death without apparent causes other than inherited thrombophilias is too limited to recommend the use of anticoagulants in this setting. Large, randomised, placebo-controlled trials are urgently needed.

Low-molecular-weight heparins for thromboprophylaxis and treatment of venous thromboembolism in pregnancy: a systematic review of safety and efficacy

To assess the safety and efficacy of low-molecular-weight heparins (LMWHs) for thromboprophylaxis and treatment of venous thromboembolism (VTE) in pregnancy, a systematic review of studies to the end of 2003 was undertaken. Data on VTE recurrence and side effects were extracted and cumulative incidences of VTE and adverse effects calculated. Of 81 reports identified, 64 reporting 2777 pregnancies were included. In 15 studies (174 patients) the indication for LMWH was treatment of acute VTE, and in 61 studies (2603 pregnancies) it was thromboprophylaxis or adverse pregnancy outcome. There were no maternal deaths. VTE and arterial thrombosis (associated with anti-phospholipid syndrome) were reported in 0.86% (95% confidence interval [CI], 0.55%-1.28%) and 0.50% (95% CI, 0.28%-0.84%) of pregnancies, respectively. Significant bleeding, generally associated with primary obstetric causes, occurred in 1.98% (95% CI, 1.50%-2.57%), allergic skin reactions in 1.80% (95% CI, 1.34%-2.37%), heparin-induced thrombocytopenia in 0%, thrombocytopenia (unrelated to LMWH) in 0.11% (95% CI, 0.02%-0.32%), and osteoporotic fracture in 0.04% (95% CI, < 0.01%-0.20%) of pregnancies. Overall, live births were reported in 94.7% of pregnancies, including 85.4% in those receiving LMWH for recurrent pregnancy loss. LMWH is both safe and effective to prevent or treat VTE in pregnancy.

Association of anticardiolipin antibody and C677T in methylenetetrahydrofolate reductase mutation in women with recurrent spontaneous abortions: a new path to thrombophilia?

CONTEXT

Recurrent spontaneous abortion (RSA) has been associated with venous thrombosis in the mother. Acquired and inherited thrombophilia factors are possible causes.

OBJECTIVE

To evaluate the association between thrombogenic factors and recurrent spontaneous abortion.

TYPE OF STUDY

Case-control study.

SETTING

Centro de Atenção Integral à Saúde da Mulher, Universidade Estadual de Campinas.

METHODS

40 ml of blood was collected from 88 women attending an RSA clinic and 88 fertile women attending a family planning clinic, to evaluate the presence of acquired and inherited thrombophilia factors. Anticardiolipin antibodies (ACA), lupus anticoagulant and deficiencies of proteins C and S and antithrombin III were evaluated by enzyme-linked immunosorbent assay (ELISA), dilute Russell Viper Venom time (dRVVT), coagulometric and chromogenic methods. DNA was amplified by the polymerase chain reaction (PCR) to study factor V Leiden and G20210A mutations in the prothrombin gene and C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene. Data were analyzed using odds ratios and a regression model for age adjustment. Fishers exact test was used to evaluate statistical relationships between associated factors and RSA.

RESULTS

ACA was detected in 11 women with RSA and one fertile woman. Heterozygous C677T was detected in 59 women with RSA and 35 fertile women. Concomitant presence of ACA and C677T was found in eight women with RSA and no fertile women (p < 0.01).

DISCUSSION

The meaning of the association between C677T mutation in the MTHFR gene and ACA is still not clear. It is possible that an inherited factor that alone would not strongly predispose a woman to thrombosis could, when associated with an acquired factor, start the process and increase the likelihood of thrombosis expression.

CONCLUSIONS

ACA and C677T in the MTHFR gene are statistically associated with RSA. The association of these two conditions is a new finding in thrombogenic factors and RSA.

Genetic thrombophilia has pleiotropic effects in pregnancy

Genetic thrombophilia has been established as a risk factor for pregnancy-associated disorders, such as thrombosis, early and late miscarriage, and pre-eclampsia. Associations between the factor V (F5) Leiden G1691A and the prothrombin/factor II (F2) G20210A SNPs and pre-eclampsia have been evaluated in over 50 association studies. A pooled analysis of 23 and 11 studies demonstrates that carriage of the F5 Leiden G1691A (p < 0.001; odds ratio [OR] 2.0; 95% confidence interval [CI] 1.6-2.5) and the F2 G20210A (p < 0.001; OR 1.8; 95% CI 1.1-2.9) SNPs is significantly associated with pre-eclampsia. Besides pre-eclampsia, genotyping for the F5 Leiden G1691A and the F2 G20210A SNPs is also useful for individual risk assessment regarding pregnancy-associated thrombosis. Carriers of the F5 Leiden G1691A SNP will develop this condition in 6.4% of heterozygotes and in 8.9-16.7% of homozygotes. A total of 6.2% of women with the F2 G20210A SNP and 17.8% of women with simultaneous carriage of the F5 Leiden G1691A and F2 G20210A SNPs will develop pregnancy-associated thrombosis. Both the F5 Leiden G1691A and F2 G20210A SNPs are also risk factors of early recurrent, late recurrent and late spontaneous miscarriage based on a published meta-analysis of 31 studies. These women may benefit from prophylactic heparinization. Six case-control and cohort studies of 687 women with genetic thrombophilia document live birth rates of 82% (181/221) using low-molecular-weight heparin or fractionated heparin compared with 20% (95/466) without therapy (p < 0.001, OR 17.7; 95% CI 12.2-25.5). Based on the data in the literature, including association studies and meta-analyses of these association studies, it can be concluded that genetic thrombophilia due to carriage of the F5 Leiden G1691A and F2 G20210A SNPs is a significant and clinically relevant risk factor for pre-eclampsia, pregnancy-associated thrombosis, and early and late miscarriages.

The one-stop recurrent miscarriage clinic: an evaluation of its effectiveness and outcome

BACKGROUND

Couples with recurrent miscarriages make several visits to specialized clinics for investigations before treatment is offered. Consequently, 'the interval' between receipt of referral and advice to try for a pregnancy is often lengthy. The objectives of this study were to examine the effect of a 'one-stop' clinic on 'the interval', throughput and the outcome from this clinic.

METHODS

The processes for investigation, management and outcomes of 189 couples seen in our Recurrent Miscarriage Clinic (RMC) and their records were reviewed.

RESULTS

The one-stop clinic reduced the interval and number of visits by 36% (206.6 to 130.4 days, P < 0.001) and by 60% (2.5 to 1, P < 0.002) respectively. The prevalence and frequency of aetiological factors were similar in those with two and three or more miscarriages (41% versus 45%, P > 0.05). The commonest aetiological factors were thrombophilias (14%) and antiphospholipid syndrome (11%). No cause was identified in 54% of cases. The pregnancy and live birth rates were best in the idiopathic group (75%), those with thrombophilias (64%) and autoimmune antibodies (83%). Older couples had the worse pregnancy rates and outcome.

CONCLUSION

A one-stop clinic significantly shortens 'the interval' between referral and initiation of treatment. Investigations should be initiated in women after two consecutive miscarriages.

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.

Hereditary thrombophilia and fetal loss: a prospective follow-up study

BACKGROUND

As the placental vessels are dependent on the normal balance of procoagulant and anticoagulant mechanisms, inherited thrombophilia may be associated with fetal loss.

OBJECTIVES

We performed a prospective study to investigate the relation between inherited thrombophilia and fetal loss, and the influence of thromboprophylaxis on pregnancy outcome.

PATIENTS AND METHODS

Women were enrolled in the European Prospective Cohort on Thrombophilia (EPCOT). These included women with factor (F)V Leiden or a deficiency of antithrombin, protein C or protein S. Controls were partners or acquaintances of thrombophilic individuals. A total of 191 women (131 with thrombophilia, 60 controls) had a pregnancy outcome during prospective follow-up. Risk of fetal loss and effect of thromboprophylaxis were estimated by frequency calculation and Cox regression modelling.

RESULTS

The risk of fetal loss appeared slightly increased in women with thrombophilia without a previous history of fetal loss who did not use any anticoagulants during pregnancy (7/39 vs. 7/51; relative risk 1.4; 95% confidence interval 0.4, 4.7). Per type of defect the relative risk varied only minimally from 1.4 for FV Leiden to 1.6 for antithrombin deficiency compared with control women. Prophylactic anticoagulant treatment during pregnancy in 83 women with thrombophilia differed greatly in type, dose and duration, precluding solid conclusions on the effect of thromboprophylaxis on fetal loss. No clear benefit of anticoagulant prophylaxis was apparent.

CONCLUSIONS

Women with thrombophilia appear to have an increased risk of fetal loss, although the likelihood of a positive outcome is high in both women with thrombophilia and in controls.

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.

Inherited thrombophilia and gestational vascular complications

The most common causes of inherited thrombophilia, the factor V Leiden and the factor II A20210 mutations, confer a higher risk of venous thromboembolism. Moreover, several studies have suggested that they can have a role in the occurrence of gestational vascular complications in otherwise unexplained recurrent fetal losses, hypertensive disorders of pregnancy and fetal growth restriction. Observational and case-control studies addressing these issues are available in literature. However, longitudinal, perspective studies are lacking. Mild hyperhomocysteinaemia can be due partly to inherited susceptibility--as the homozygous carriership of the T677 variant in the gene encoding 5,10-methylenetetrahydrofolate reductase (MTHFR). Case-control studies have been carried out on a possible association between unexplained fetal losses and mild hyperhomocysteinaemia. Although case-control and perspective studies are available on hyperhomocysteinaemia and other gestational vascular complications the data are conflicting.Intervention studies have been carried out to prevent adverse obstetric outcomes in women with factor V Leiden or factor II A20210 mutations and previous adverse outcomes. Although these are not randomized controlled trials, all have found significantly better outcomes in treated pregnancies compared to those of untreated pregnancies in the same women.

Clinical utility of factor V leiden (R506Q) testing for the diagnosis and management of thromboembolic disorders

OBJECTIVE

To review the current state of the art regarding the role of the clinical laboratory in diagnostic testing for the factor V Leiden (FVL) thrombophilic mutation (and other protein C resistance disorders), and to generate, through literature reviews and opinions of recognized thought-leaders, expert consensus recommendations on methodology and diagnostic, prognostic, and management issues pertaining to clinical FVL testing.

DATA SOURCES, EXTRACTION, AND SYNTHESIS

An initial thorough review of the medical literature and of current best clinical practices by a panel of 4 experts followed by a consensus conference review, editing, and ultimate approval by the majority of a panel of 28 additional coagulation laboratory experts.

CONCLUSIONS

Consensus recommendations were generated for topics of direct clinical relevance, including (1) defining those patients (and family members) who should (and should not) be tested for FVL; (2) defining the preferred FVL laboratory testing methods; and (3) defining the therapeutic, prophylactic, and management ramifications of FVL testing in affected individuals and their family members. As FVL is currently the most common recognized familial thrombophilia, it is hoped that these recommendations will assist laboratorians and clinicians caring for patients (and families) with this common mutation.

The use of low-molecular-weight heparin for the management of venous thromboembolism in pregnancy

Thromboembolic disease is a rare, but important, complication of pregnancy that remains a leading non-obstetric cause of maternal death. The prevention and management of venous thromboembolism (VTE) in pregnant women is a complex area of medicine: a balance must be found between protecting the health of the mother and minimizing the risk to the unborn fetus. Until now, unfractionated heparin has been regarded as the drug of choice for the prevention and treatment of VTE during pregnancy. However, because of its significant side effects (osteoporosis and heparin-induced thrombocytopenia), the inconvenient mode of administration and need for monitoring, unfractionated heparin is now being replaced by low-molecular-weight heparin (LMWH). There is a convincing body of clinical evidence from well-designed studies and prospective case series that supports the efficacy and safety of LMWH in pregnant women. There are also encouraging observations on the efficacy of LMWH in the prevention of severe obstetric complications, which are frequently associated with inherited or acquired thrombophilias. The recently-published guidelines of The American College of Chest Physicians (ACCP), summarized in this review, allows the development of higher clinical standards. However, there is concern over the greater cost of LMWH compared with unfractionated heparin and oral anticoagulants, and cost-effectiveness studies are needed.

Thrombophilia and pregnancy loss

Thrombophilia is defined as a tendency to thrombosis. The association between specific thrombophilic defects--both inherited and acquired--and pregnancy loss is a rapidly developing field. However, apart from antiphospholipid antibodies (aPL), an acquired thrombophilic defect, the role of other defects in the haemostatic pathways remains to be established. In this invited review we discuss the recent advances in our understanding of aPL related pregnancy loss, the association between genetic thrombophilic mutations and pregnancy outcome and the role of whole blood haemostasis testing in the investigation of women with recurrent miscarriage.

Thrombophilia and its treatment in pregnancy

Pulmonary embolism is the most common cause of maternal death during pregnancy and the puerperium in the industrialized world. The risk of venous thromboembolism (VTE) in pregnancy is 0.05%-1.8%, 6 times greater than in the non-pregnant state. The risk is increased in women over 35 years and those with obesity, previous VTE, operative delivery, or underlying thrombophilia. Women presenting with recurrent miscarriages, preeclampsia, intrauterine growth restriction, abruptio placentae, or stillbirth (all associated with microvascular thrombosis in placental blood vessels) have high incidence (65%) of thrombophilia. About 70% of the women who present with VTE during pregnancy are carriers of hereditary or acquired thrombophilia. Treatment of women with VTE during pregnancy, and especially those with thrombophilia, requires individualized dosing and duration of antithrombotic therapy and the formulation of thromboprophylactic strategies for future pregnancies. Warfarin is contraindicated during the first trimester due to fetotoxicity; unfractionated heparin (UFH) is associated with practical disadvantages and the risk of heparin-induced thrombocytopenia (HIT) and osteoporosis with long-term use. Low molecular weight heparins (LMWHs) are convenient to use, do not cross the placenta, carry a lower risk of HIT and osteoporosis, and are safe and effective. LMWHs are replacing UFH as the anticoagulant of choice during pregnancy and improve pregnancy outcome in women with a history of obstetric complications and confirmed thrombophilia.

Factor V Leiden: a clinical review

Factor V Leiden is the most prevalent genetic thrombophilia in people of European descent. Since its discovery, much clinical information has been gathered regarding the distribution and prevalence of the genetic mutation, the mechanism of thrombophilia, and its association with clinical thromboembolic events. Although its association with venous thromboembolism is clear, the role of Factor V Leiden in other disease states is not clear. A review of the literature regarding the mechanism of hypercoagulability, genetic versus functional diagnostic tests, screening issues, relationship to arterial thromboses, pregnancy and pregnancy complications, and treatment are discussed.