Heparin and low-dose aspirin restore placental human chorionic gonadotrophin secretion abolished by antiphospholipid antibody-containing sera

Trophoblast Cell Function in the Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a complex thrombo-inflammatory autoimmune disease characterized by the presence of antiphospholipid antibodies (aPL). Women with APS are at high risk of recurrent early pregnancy loss as well as late obstetrical complications-premature birth due to placental insufficiency or severe preeclampsia. Accumulating evidence implies that vascular thrombosis is not the only pathogenic mechanism in obstetric APS, and that the direct negative effect of aPL on the placental cells, trophoblast, plays a major role. In this review, we summarize the current findings regarding the potential mechanisms involved in aPL-induced trophoblast dysfunction. Introduction on the APS and aPL is followed by an overview of the effects of aPL on trophoblast-survival, cell function and aPL internalization. Finally, the implication of several non-coding RNAs in pathogenesis of obstetric APS is discussed, with special emphasis of their possible role in trophoblast dysfunction and the associated mechanisms.

Antiphospholipid Syndrome in Pregnancy: New and Old Pathogenetic Mechanisms

The antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized, according to the Sydney criteria, by the persistent presence of autoantibodies directed against phospholipid-binding proteins associated with thrombosis and/or obstetrical complications. The most frequent complications in obstetric antiphospholipid syndrome are recurrent pregnancy losses and premature birth due to placental insufficiency or severe preeclampsia. In recent years, vascular APS (VAPS) and obstetric APS (OAPS) have been described as two different clinical entities. In VAPS, antiphospholipid antibodies (aPL) interfere with the mechanisms of coagulation cascade and the 'two hit hypothesis' has been suggested to explain why aPL positivity does not always lead to thrombosis. OAPS seems to involve additional mechanisms, such as the direct action of anti-β2 glycoprotein-I on trophoblast cells that can lead to a direct placental functional damage. Furthermore, new actors seem to play a role in the pathogenesis of OAPS, including extracellular vesicles, micro-RNAs and the release of neutrophil extracellular traps. The aim of this review is to investigate the state-of-the-art antiphospholipid syndrome pathogenesis in pregnancy, in order to provide a comprehensive overview of both old and new pathogenetic mechanisms involved in this complex disease.

In vitro fertilization outcomes in women with antiphospholipid antibodies circulation

Background: Antiphospholipid antibodies (aPL) have a multifaceted effect on the hemostatic system, damaging all its protective links.Aim: To study the effect of APA on outcomes of assisted reproductive technologies (ART).Study design: We examined 267 women with infertility, who planned pregnancy using ART. They included 178 women with IVF failure (I group) and 89 women with pregnancy after the IVF program (II group). The comparison group consisted of 80 pregnant women after IVF (male factor); a control group included 80 pregnant women with physiological pregnancy. Results of study demonstrated a high frequency of aPL circulation in a group of women with IVF failures. Overall, the proportion of aPL among all 267 women who planned pregnancy with ART was 32.6%. Elevated levels of aPL in the structure of causes of IVF failures (group I) were observed in 42.1% of them. Among women whose pregnancy occurred with ART (II group) the rate of APA was 19.1%. In the comparison group, in 6.3% of cases, aPL circulation was observed. In the control group, the rate was 3.4%.Conclusion: Considering the high percentage of aPL circulation in the case of IVF failures, authors think that high titers of aPL are a temporary contraindication for IVF. Patients with a history of aPL circulation are required to receive anticoagulant therapy from the first days of the hormonal protocol. The drug of choice is a group of low molecular weight heparins (LMWH). An individual approach is extremely important with the possible identification of causes of IVF failures and selective therapy, which leads to a significant improvement in the outcomes of the IVF program.

Aspirin: The Mechanism of Action Revisited in the Context of Pregnancy Complications

Aspirin is one of the most frequently used and cheapest drugs in medicine. It belongs to the non-steroidal anti-inflammatory drugs with a wide range of pharmacological activities, including analgesic, antipyretic, and antiplatelet properties. Currently, it is accepted to prescribe a low dose of aspirin to pregnant women who are at high risk of preeclampsia (PE) because it reduces the onset of this complication. Another pregnancy alteration in which a low dose of aspirin is recommended is the obstetric antiphospholipid syndrome (APS). The most recognized mechanism of action of aspirin is to inhibit the synthesis of prostaglandins but this by itself does not explain the repertoire of anti-inflammatory effects of aspirin. Later, another mechanism was described: the induction of the production of aspirin-triggered lipoxins (ATLs) from arachidonic acid by acetylation of the enzyme cyclooxygenase-2. The availability of a stable analog of ATL has stimulated investigations on the use of this analog and it has been found that, similar to endogenously produced lipoxins, ATL resolves inflammation and acts as antioxidant and immunomodulator. If we consider that in PE and in the obstetric APS, there is an underlying inflammatory process, aspirin might be used based on the induction of ATL. The objective of this review is to revisit the old and new mechanisms of action of aspirin. In particular, it intends to show other potential uses of this drug to prevent certain pregnancy complications in the light of its ability to induce anti-inflammatory and pro-resolving lipid-derived mediators.

Modulation of antiphospholipid antibodies-induced trophoblast damage by different drugs used to prevent pregnancy morbidity associated with antiphospholipid syndrome

PROBLEM

Women with antiphospholipid antibodies (aPLs) present a risk of pregnancy morbidity (PM), vascular thrombosis (VT), or both (PM/VT). aPLs affect trophoblast function, and the aim of this study was to determine the modulation of this aPL-induced damage by different drugs.

METHOD OF STUDY

IgG was obtained from women with PM and PM/VT positive to aPLs. Binding of IgG to trophoblastic cells, proliferation, mitochondrial membrane integrity, and trophoblast invasion were assessed. The effect of enoxaparin, aspirin, and aspirin-triggered lipoxin (ATL) were evaluated as well as signal transducer and activator of transcription 3 (STAT3) phosphorylation.

RESULTS

IgG from women with aPLs strongly binds to trophoblastic cells. Integrity of mitochondrial membrane was reduced, and proliferation was increased by IgG-PM/VT. Both IgG-PM and IgG-PM/VT decreased trophoblast invasion, which was restored by enoxaparin, aspirin, and ATL. IgG-PM triggered reduction in STAT3 phosphorylation.

CONCLUSION

Some drugs used to prevent aPL-induced PM modulated the alteration of trophoblast function.

The role of anti-phospholipid antibodies in autoimmune reproductive failure

Anti-phospholipid antibodies (aPL) are autoantibodies that are associated with thrombosis and a range of pregnancy complications including recurrent pregnancy loss and pre-eclampsia. The three clinically relevant, well-characterized aPL are anti-cardiolipin antibodies, lupus anticoagulant and anti-beta-2-glycoprotein I (β2GPI) antibodies. aPL do not bind directly to phospholipids but instead bind to a plasma-binding ‘cofactor’. The most extensively studied cofactor is β2GPI, whose role in pregnancy is not fully elucidated. Although the pathogenicity of aPL in recurrent pregnancy loss is well established in humans and animal models, the association of aPL with infertility does not appear to be causative. aPL may exert their detrimental effects during pregnancy by directly binding trophoblast cells of the placenta, altering trophoblast signalling, proliferation, invasion and secretion of hormones and cytokines, and by increasing apoptosis. Heparin is commonly used to treat pregnant women with aPL; however, as thrombotic events do not occur in the placentae of all women with aPL, it may exert a protective effect by preventing the binding of aPL to β2GPI or by acting through non-thrombotic pathways. The aim of this review is to present evidence summarizing the current understanding of this field.

Human IgG Antinuclear Antibodies Induce Pregnancy Loss in Mice by Increasing Immune Complex Deposition in Placental Tissue: In Vivo Study

PROBLEM

A threefold higher prevalence of antinuclear antibodies (ANA) has been reported in patients with recurrent pregnancy loss (RPL). Nevertheless, the role of ANA in reproductive failure is still unclear. The aim of this study was to investigate the role of ANA during early pregnancy in vivo.

METHOD OF STUDY

We used pregnant mice treated with immunoglobulin G (IgG) obtained from normal healthy subjects (NHS); ANA(+) sera of patients with RPL; and ANA(+) sera from women with uncomplicated pregnancies (HW). Placental immunohistochemical/immunofluorescence staining was performed to detect complement and immune complex deposition. ELISA was performed to evaluate complement levels.

RESULTS

ANA(+) IgG from RPL women significantly increased embryo resorption rate, reduced C3, and increased C3a serum levels compared to NHS IgG or ANA(+) -HW IgG. Increased C3 deposition and increased immune complex staining in placental tissues from mice treated with ANA(+) -RPL IgG fraction compared to NHS- and ANA(+) -HW-IgG-treated mice were found.

CONCLUSION

ANA(+) IgG injection in mice is able to induce fetal resorption and complement activation. The presence on placental tissues of immune complexes and complement fragments suggests the complement activation as a possible mechanism of placental damage.

Aspirin-triggered lipoxin prevents antiphospholipid antibody effects on human trophoblast migration and endothelial cell interactions

OBJECTIVE

Antiphospholipid antibodies (aPL) interfere with several physiologic functions of human trophoblasts, including reducing their ability to migrate, decreasing their production of angiogenic factors, and inducing an inflammatory response. This may provide the underlying mechanism by which aPL responses lead to recurrent pregnancy loss or preeclampsia in women with obstetric antiphospholipid syndrome (APS). Although treatment with heparin may reduce the rate of recurrent pregnancy loss, the risk of preeclampsia remains high. Therefore, alternative treatments are needed for the management of pregnant patients with APS. Since aspirin-triggered lipoxins (ATLs) have immune and angiogenic modulatory properties, the objective of this study was to determine the effects of the ATL 15-epi-lipoxin A4 on the function of aPL-altered human trophoblasts in the first trimester of pregnancy.

METHODS

A first-trimester human trophoblast cell line (HTR8) was treated with mouse anti-human β2 -glycoprotein I monoclonal antibodies (aPL) in the presence or absence of the ATL 15-epi-lipoxin A4 . Trophoblast migration and interactions with endometrial endothelial cells were measured using Transwell and coculture assays. Trophoblast secretion of cytokines and angiogenic factors was measured by enzyme-linked immunosorbent assay.

RESULTS

Treatment of HTR8 cells with ATL reversed the aPL-induced decrease in trophoblast migration, an effect that appeared to be regulated through restoration of interleukin-6 production. Using a model of spiral artery transformation, aPL and sera from APS patients with pregnancy morbidity disrupted trophoblast-endothelial cell interactions, and treatment with ATL restored the stability of the cocultures. In contrast, ATL treatment did not resolve the proinflammatory and antiangiogenic responses of trophoblasts induced by aPL.

CONCLUSION

These findings indicate that ATLs may have some benefits in terms of preventing the effects of aPL on trophoblast function, which raises the possibility of the use of ATLs as an adjuvant therapy in women with aPL.

Low molecular weight heparin use in unexplained recurrent miscarriage

Objective: The aim of the study was to investigate whether the use of low molecular weight heparin (LMWH) improve live birth rates when compared with control group in patients with unexplained recurrent miscarriages (URM).

Methods: In this prospective observational study 150 women with a history of two or more previous unexplained first trimester pregnancy loss who received LMWH; either enoxaparin (n=50), tinzaparin (n=50) or nothing (n=50) were followed for the pregnancy outcome measures. Only the patients who have used standardized dosage of LMWH (4000 IU/day enoxaparin or 3500 IU/day tinzaparin ) were included to the study. The primary end point was the live birth rate and secondary end points were the side effects, late pregnancy complications and neonatal outcome in the study cohorts.

Results: Live birth was achieved 85% of the LMWH group and 66% of the control group (p=0.007). According to the subgroup analysis; live birth rates did not differ significantly between the enoxaparin and tinzaparin group (84% and 86%, respectively). Maternal and neonatal side effects were not statistically significant among the study participants.

Conclusion: Thromboprophylaxis with LMWH resulted in a improved live-birth rate in patient with 2 or more consecutive unexplained recurrent pregnancy loss. Nevertheless these findings need to be confirmed in larger randomized trials.

Antiphospholipid antibodies and the placenta: a systematic review of their in vitro effects and modulation by treatment

BACKGROUND

Antiphospholipid antibodies (aPL) are a family of auto-antibodies that are associated with an increased risk of recurrent miscarriage, intrauterine growth restriction and preterm birth. The placenta is a major target of aPL and it is likely that these antibodies promote pregnancy morbidity by affecting trophoblast function. Numerous studies have investigated the effect of aPL on trophoblast function in vitro. However, different trophoblast models and a variety of culture conditions have been employed, resulting in a myriad of different reported findings. This review systematically summarized those published studies that have investigated the effect of aPL on trophoblast function in vitro. In addition, the reported effects of pharmacological treatment on trophoblast function in the presence of aPL were also systematically reviewed.

METHODS

PubMed, Scopus, Embase and Web of Science databases were searched using the keywords 'placenta OR trophoblast' AND 'antiphospholipid antibody OR antiphospholipid syndrome' up to 25 April 2014. Studies were excluded based on the absence of appropriate controls. The effects of aPL on trophoblast proliferation, death, syncytialization, invasion, hormone production, cytokine production, coagulation and complement activation were recorded. The effects of different treatments on the function of trophoblasts in the presence of aPL were also recorded.

RESULTS

A total of 1071 records were retrieved from the four databases. After removing duplicates, the titles and abstracts of 529 articles were reviewed. Of those, 48 articles were read and relevant experimental results were extracted from 47 articles.

CONCLUSIONS

This systematic review provides an overview of all the studies performed to date on the effects of aPL on trophoblast function in vitro. There is considerable support for aPL decreasing trophoblast viability, syncytialization and invasion in vitro. Some work has also suggested that aPL may affect the production of hormones and signalling molecules by trophoblasts, and may stimulate coagulation and complement activation in vitro. Current reports of the in vitro effects of therapeutic treatments on trophoblast function in the presence of aPL are inconclusive. This systematic review has highlighted many gaps in our knowledge of how aPL work and may direct future research in this area.

Classic and cutting-edge strategies for the management of early pregnancy loss

There are few conditions in medicine associated with more heartache to patients than recurrent pregnancy loss (RPL). The management of early RPL is a formidable clinical challenge for physicians. Great strides have been made in characterizing the incidence and diversity of this heterogeneous disorder, and a definite cause of pregnancy loss can be established in more than half of couples after a thorough evaluation. In this review, current data are evaluated and a clear roadmap is provided for the evaluation and treatment of RPL.

Management of women with recurrent pregnancy losses and antiphospholipid antibody syndrome

Antiphospholipid antibodies (aPL) have been associated with recurrent pregnancy losses (RPL) and other obstetrical complications. The diagnostic criteria for the classical antiphospholipid antibody syndrome (APS) have been utilized for the detection of obstetrical APS in women with RPL. However, laboratory findings and immunopathology of obstetrical APS are significantly different from those of classical APS. In addition, many women with RPL who have positive aPL do not have symptoms consistent with the current APS criteria. The induction of a proinflammatory immune response from trophoblasts and complement activation by aPL rather than thromboembolic changes has been reported as a major immunopathological feature of obstetrical APS. Heparin treatment has been reported to be effective in prevention of early pregnancy loss with APS but not for the late pregnancy loss or complications. The complex effects of heparin may explain the limited efficacy of heparin treatment in RPL. New diagnostic criteria for obstetrical APS are needed urgently, and new therapeutic approaches should be explored further.

The effect of hereditary versus acquired thrombophilia on triple test Down's syndrome screening

OBJECTIVE

To compare the profile of mid gestation triple test serum markers between a cohort of women with history of pregnancy complications with hereditary versus acquired thrombophilia. All were treated with low molecular weight heparin (LMWH) prior to 12 weeks' gestation.

METHODS

A retrospective analysis of second trimester maternal serum screening results for Down syndrome was performed comparing women with inherited versus acquired thrombophilia, all treated with LMWH. The test results were calculated from the combination of triple serum markers and maternal age, and expressed as a multiple of the gestation normal medians (MoM). Results in the study groups were compared with MoM values calculated from our local population (controls).

RESULTS

The median human chorionic gonadotropin (hCG) level was higher only in the acquired thrombophilia group (N = 47) as compared with the control group (1.3 vs. 0.99 MoM, P = 0.005), and not different between the hereditary thrombophilia group (N = 60) (1.1 MoM) and the control group. Alpha-fetoprotein and unconjugated estriol MoMs did not differ between women with inherited (0.95, 0.97), acquired thrombophilia (0.99, 0.90), and controls (1.01, 0.98), respectively.

CONCLUSION

In the interpretation of second trimester maternal serum screening, consideration should be given to the higher hCG maternal serum levels that may occur in women with acquired thrombophilia, even those treated early in pregnancy with LMWH. The higher hCG serum levels may signal the possibility of placental dysfunction, rather than fetal aneuploidy.

Effect of Low Molecular Weight Heparins (LMWHs) on antiphospholipid Antibodies (aPL)-mediated inhibition of endometrial angiogenesis

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity in the presence of circulating antiphospholipid antibodies (aPL). Different pathogenic mechanisms for aPL-mediated pregnancy failure have been proposed. In particular a direct effect of aPL on both maternal and fetal side of the placental tissue has been reported, since their reactivity with β2-glycoprotein I (β2GPI) makes them adhere to trophoblast and human endometrial endothelial cell (HEEC) membranes. β2GPI can be recognized by aPL that, once bound, interfere with both trophoblast functions and with the HEEC differentiation.APS patients can be successfully treated with Low Molecular Weight Heparin (LMWH). Recent reports suggest that LMWH acts through mechanisms alternative to its well known anticoagulant effect, because of its ability to bind β2GPI. In our previous studies, we showed that LMWH is able to reduce the aPL binding to trophoblasts and restore cell invasiveness and differentiation. So far, however, no study has described its effects on endometrial angiogenesis.The aim of our research was to evaluate whether two LMWHs, tinzaparin and enoxaparin, have an effect on the aPL-inhibited endometrial angiogenesis. This prompted us to investigate: (i) in vitro HEEC angiogenesis through a Matrigel assay; (ii) VEGF secretion by ELISA; (iii) matrix metalloproteinase-2 (MMP-2) activity by gelatin zymography; (iv) Nuclear Factor-κB (NF-κB) DNA binding activity by colorimetric assay; (v) STAT-3 activation by a sandwich-ELISA kit. Furthermore, using an in vivo murine model we investigated the LMWHs effects on angiogenesis.We demonstrated that the addition of LMWHs prevents aPL-inhibited HEEC angiogenesis, both in vitro and in vivo, and is able to restore the aPL inhibited NF-κB and/or STAT-3 activity, the VEGF secretion and the MMPs activity.The demonstration of a beneficial role for LMWHs on the aPL-inhibited HEEC angiogenesis might provide additional mechanisms whereby this treatment protects early pregnancy in APS.

Low-molecular weight heparin in patients with recurrent early miscarriages of unknown aetiology

The aim of this randomised prospective study was to assess the efficacy of early thromboprophylaxis with low-molecular weight heparin (LMWH) in women with a history of recurrent first trimester spontaneous abortion or miscarriages without identifiable causes vs no treatment. The study comprised of 340 women with unexplained spontaneous recurrent miscarriages. Patients in group A were prescribed LMWH (Enoxaparin sodium 0.2 ml, 20 mg, once daily subcutaneously) from the time of confirmation of fetal viability by ultrasonography until 34 weeks' gestation, and folic acid tablets 0.5 mg daily until 13 weeks' gestation. Patients in group B were given folic acid tablets 0.5 mg daily until 13 weeks' gestation. Termination of pregnancy was the primary outcome. There was a significant difference in the incidence of both early (4.1% vs 8.8%) and late miscarriages (1.1% vs 2.3%) in group A than in group B, respectively. There were no differences between both groups as regards the occurrence of pre-eclampsia, placental abruption, caesarean delivery, intra-partum bleeding or ecchymosis at operative wounds. There were no differences in most of the neonatal values between both groups. However, the mean birth weight was significantly higher in group A. LMWH seems to be a safe drug and effective in significantly reducing the incidence of recurrent miscarriages of unknown aetiology when given in the first trimester and continued throughout pregnancy.

Pregnancies Complicated with Antiphospholipid Syndrome: The Pathogenic Mechanism of Antiphospholipid Antibodies: A Review of the Literature

There are several possible mechanisms by which antiphospholipid antibodies (aPL) may have adverse effects on placental functions. Examination of placentas and first-trimester decidua from antiphospholipid syndrome-complicated pregnancies has found little evidence of specific thrombotic placental pathology. It is now generally accepted that the clinically relevant aPL bind to proteins with affinity for phospholipids. The most important epitope for antiphospholipid syndrome-related aPL resides on beta2-glycoprotein-I (beta2GPI). aPL detected by anti-beta2GPI assays are associated with fetal loss. During differentiation to syncytium, trophoblasts express cell membrane anionic phospholipids that can bind beta2GPI. Adhered beta2GPI can be recognized by the antibodies that, once bound, interfere with trophoblast cell maturation, resulting in defective placentation. The improved outcome of pregnancies treated with heparin stimulated interest on the drug's mechanism of action. Several mechanisms could explain its beneficial effects in addition to a direct effect of heparin on the coagulation cascade. It might reduce the binding of aPL, inflammation by inhibiting complement activation, and might facilitate implantation. Further investigations are needed to better understand how aPL induce obstetric complications and to better clarify the functional role of heparin in the human placenta, leading to more successful therapeutic options.

Pathogenic role of anti-β2-glycoprotein I antibodies on human placenta: functional effects related to implantation and roles of heparin

Most of the clinical manifestations of the antiphospholipid syndrome (APS) can be related to thrombotic events; however, placental thrombosis cannot explain all of the pregnancy complications that occur in women with this syndrome. In this regard, it has been hypothesized that antiphospholipid (aPL) antibodies can directly attack trophoblasts, but it is still unclear what pathogenetic mechanisms play a role and which aPL antibodies subpopulations are involved. Although it has been assumed that aPL antibodies are directed against anionic phospholipids (PLs), current advances in the field suggest that antibodies to PL-binding plasma protein such as beta2-glycoprotein-I (beta2-GPI) are the clinically relevant aPL antibodies. It appears that following the attachment of beta2-GPI to PLs, both molecules undergo conformational changes that result in the exposure of cryptic epitopes within the structure of beta2-GPI allowing the subsequent binding of antibodies. aPL antibodies detected by anti-beta2-GPI assays are associated with fetal loss. However, there is still debate on how the antibodies might induce the obstetrical manifestations. The significantly improved outcome of pregnancies treated with heparin has stimulated interest in the drug's mechanisms of action. Several mechanisms could explain its beneficial effects, because in addition to a direct effect of heparin on the coagulation cascade, it might protect pregnancies by reducing the binding of aPL antibodies, reducing inflammation, facilitating implantation and/or inhibiting complement activation. Further investigations are needed to better understand how aPL antibodies induce obstetric complications and to better clarify the functional role of heparin in the human placenta leading to more successful therapeutic options.

Recurrent miscarriage

Many human conceptions are genetically abnormal and end in miscarriage, which is the commonest complication of pregnancy. Recurrent miscarriage, the loss of three or more consecutive pregnancies, affects 1% of couples trying to conceive. It is associated with psychological morbidity, and has often proven to be frustrating for both patient and clinician. A third of women attending specialist clinics are clinically depressed, and one in five have levels of anxiety that are similar to those in psychiatric outpatient populations. Many conventional beliefs about the cause and treatment of women with recurrent miscarriage have not withstood scrutiny, but progress has been made. Research has emphasised the importance of recurrent miscarriage in the range of reproductive failure linking subfertility and late pregnancy complications and has allowed us to reject practice based on anecdotal evidence in favour of evidence-based management.

Antiphospholipid syndrome

PURPOSE OF REVIEW

To review the recently published studies that can guide physicians in the management of persistently antiphospholipid antibody (aPL)-positive patients.

RECENT FINDINGS

Two recent prospective randomized controlled trials of two intensities of warfarin concluded that both moderate and high-intensity anticoagulation are similarly protective in antiphospholipid syndrome patients after the first thrombosis. Despite lack of controlled studies, there is experimental evidence that hydroxychloroquine and statins may play a role in the management of aPL-positive patients. In the mouse model of antiphospholipid syndrome that involves the injection of high-titer antiphospholipid syndrome human serum, complement activation is essential in aPL-mediated fetal loss and heparin prevents aPL-induced complement activation.

SUMMARY

Primary thrombosis prevention in persistently aPL-positive individuals lacks an evidence-based approach; elimination of reversible thrombosis risk factors and prophylaxis during high-risk periods is crucial. Secondary thrombosis prevention in persistently aPL-positive individuals lacks a risk-stratified approach; although the current recommendation is life-long warfarin, the necessity, duration, and the intensity of warfarin are still debated. Catastrophic antiphospholipid syndrome patients usually receive a combination of anticoagulation, corticosteroids, intravenous immunoglobulin, and plasma exchange; there is a clear need to test new agents. A common strategy to prevent fetal loss in aPL-positive patients with history of pregnancy morbidities is low-dose aspirin and heparin; if patients fail this regimen, the next step is the addition of intravenous immunoglobulin although this is not supported by controlled studies. Currently, there is no evidence that anticoagulation is effective for nonthrombotic manifestations of antiphospholipid antibodies.

Heparin prevents programmed cell death in human trophoblast

Heparin is used clinically for the prevention of pregnancy complications associated with prothrombotic disorders, especially antiphospholipid antibody syndrome. Recent studies have suggested that heparin may exert direct effects on placental trophoblast, independently of its anticoagulant activity. We now demonstrate that heparin abrogates apoptosis of primary first trimester villous trophoblast in response to treatment with the pro-inflammatory cytokines interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. This multifunctional glycosaminoglycan also inhibited apoptosis induced by other agents, including staurosporin, broad-spectrum kinase inhibitor and thrombin. Furthermore, heparin attenuated caspase-3 activity, a hallmark of apoptosis, in human first trimester villous and extravillous trophoblast cell lines treated with peptidoglycan, a Toll-like receptor-2 agonist isolated from Staphylococcus aureus. The ability of heparin to antagonize cell death induced by such diverse apoptotic signals suggested that it acts as a survival factor for human trophoblast. We demonstrate that heparin, like epidermal growth factor (EGF) and heparin-binding EGF (HB-EGF), elicits phosphorylation of the EGF receptor and activation of the phosphatidyl inositol 3-kinase (PI3K)-, the extracellular signal-related kinase 1/2 (ERK1/2)- and the c-Jun NH2 terminal kinase (JNK)-signal transduction pathways in primary villous trophoblast. In summary, we have demonstrated that heparin activates multiple anti-apoptotic pathways in human trophoblast. Our results suggest that heparin may be useful in the management of at-risk patients, even in the absence of an identifiable thrombophilic disorder.

New Treatments for Antiphospholipid Syndrome

Challenges in new drug development for APS include the controversy about the strength of association between aPL and thrombotic events, and unknown mechanism of aPL-induced thrombosis. In the long-term management of patients who have APS, controlled studies with warfarin alternatives (such as antiplatelet agents), the new anticoagulant agents (such as direct and indirect thrombin inhibitors), and newer therapeutic agents are vital. It is highly possible that the current "antithrombotic" approach to patients who are aPL-positive will be replaced by a "more specifically targeted, anti-inflammatory or immunomodulatory" approach in the future.

Heparin treatment in pregnancy loss: Potential therapeutic benefits beyond anticoagulation

Interventions with heparin therapies have increased fetal survival in patients with antiphospholipid syndrome (APS). In this review, several physiological and pharmacological effects of heparin are described. These different mechanisms of action could explain the beneficial effects of heparin in the treatment of recurrent pregnancy loss in patients with APS. In addition to direct effects of heparin on the coagulation cascade, heparin might protect pregnancies by reducing the binding of antiphospholipid antibodies, reducing inflammation, facilitating implantation and or inhibiting complement activation.

Prevention of recurrent miscarriage for women with antiphospholipid antibody or lupus anticoagulant

BACKGROUND

A range of treatments have been proposed to improve pregnancy outcome in recurrent pregnancy loss associated with antiphospholipid antibody (APL). Small studies have not resolved uncertainty about benefits and risks.

OBJECTIVES

To examine outcomes of all treatments given to maintain pregnancy in women with prior miscarriage and APL.

SEARCH STRATEGY

We searched the Pregnancy and Childbirth Group's Trials Register (30 May 2004), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2003), MEDLINE (1966 to June 2003), EMBASE (1988 to June 2003), Lupus (volume one to eight, 1991 to 1999) and conference proceedings from the International Symposium on APL up to 1999.

SELECTION CRITERIA

Randomised or quasi-randomised, controlled trials of interventions in pregnant women with a history of pregnancy loss and APL.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed quality and extracted data for studies up to December 1999. One review author performed this for studies after 1999.

MAIN RESULTS

Thirteen studies were found (849 participants). The quality was not high; 50% had clear evidence of allocation concealment. Participant characteristics varied between trials. Unfractionated heparin combined with aspirin (two trials; n = 140) significantly reduced pregnancy loss compared to aspirin alone (relative risk (RR) 0.46, 95% confidence interval (CI) 0.29 to 0.71). Low molecular weight heparin (LMWH) combined with aspirin compared to aspirin (one trial; n = 98) did not significantly reduce pregnancy loss (RR 0.78, 95% CI 0.39 to 1.57). There was no advantage in high-dose, over low-dose, unfractionated heparin (one trial; n = 50). Three trials of aspirin alone (n = 135) showed no significant reduction in pregnancy loss (RR 1.05, 95% CI 0.66 to 1.68). Prednisone and aspirin (three trials; n = 286) resulted in a significant increase in prematurity when compared to placebo, aspirin, and heparin combined with aspirin, and an increase in gestational diabetes, but no significant benefit. Intravenous immunoglobulin +/- unfractionated heparin and aspirin (two trials; n = 58) was associated with an increased risk of pregnancy loss or premature birth when compared to unfractionated heparin or LMWH combined with aspirin (RR 2.51, 95% CI 1.27 to 4.95). When compared to prednisone and aspirin, intravenous immunoglobulin (one trial; n = 82) was not significantly different in outcomes.

AUTHORS' CONCLUSIONS

Combined unfractionated heparin and aspirin may reduce pregnancy loss by 54%. Large, randomised controlled trials with adequate allocation concealment are needed to explore potential differences between unfractionated heparin and LMWH.

Antiphospholipid antibodies prevent extravillous trophoblast differentiation

OBJECTIVE

We investigated the hypothesis that antiphospholipid antibodies (aPL) have a detrimental effect on human extravillous trophoblast (EVT) differentiation into giant multinucleated cells "in vitro."

DESIGN

The EVT were isolated from the placental chorion using enzymatic digestion and Percoll gradient centrifugation. After 24, 36, and 48 hours in culture, giant multinuclear cells (GMC) were identified by immunohistochemistry using antibodies to cytokeratin 7 and counted.

SETTING

An academic research laboratory.

PATIENT(S)

Placentas were donated by women having an elective cesarean section for a normal pregnancy at term.

MAIN OUTCOME MEASURE(S)

This model was then used to investigate the effect of two different monoclonal aPL to beta2-glycoprotein 1 (IIC5 and ID2), and control mouse IgG antibody on EVT differentiation.

RESULT(S)

Freshly isolated EVT were nonproliferative but moved together losing their intervening cell walls and differentiated into GMC. Maximal numbers of GMC were detected after 48 hours of culture. The aPL, IIC5, and ID2 significantly inhibited GMC formation, whereas the mouse IgG control had no effect.

CONCLUSION(S)

Antiphospholipid antibodies can inhibit EVT differentiation and GMC formation "in vitro" suggesting that a failure of trophoblast differentiation and subsequent uteroplacental development may be an underlying pathology in antiphospholipid syndrome-associated pregnancy loss.

Current debates in antiphospholipid syndrome: the acquired antibody-mediated thrombophilia

Antiphospholipid (APL) syndrome is the most common form of acquired thrombophilia. It can cause significant morbidity and even mortality. The term "APL antibodies" represents a heterogeneous group of antibodies associated with this disorder. Currently no single assay can identify every APL antibody. Clinically relevant APL antibodies are mainly anticardiolipin antibodies (ACA) detected by solid phase enzyme-linked immunosorbent assay (ELISA) and lupus anticoagulants (LA) demonstrated by in vitro coagulation assay. However, there are some other antibodies associated with the APL syndrome (i.e., subgroup APL antibodies). ACAs, LAs, and subgroup APL antibodies represent intersecting, but non-identical, subsets of autoantibodies. Thus, those autoantibodies may coexist or may occur independently. Any organ system and any size of vessel can be affected during the clinical course of the disease. Therefore, the APL syndrome can manifest itself in a wide variety of clinical thrombotic features. Fetal loss and pregnancy morbidity represent a specific challenge. Despite tremendous advances in the understanding of the pathogenesis of APL syndrome during the past decade, the mainstay of management is still anticoagulation. However, there is no general agreement regarding the duration and intensity of anti-coagulant therapy. In this review, we focused on the current dilemmas and their present clarifications in the wide clinicopathologic spectrum of APL syndrome and APL antibody-related distinct pathologic conditions.

Drug intervention in early pregnancy after assisted reproductive technology

Implantation in humans is a complex, closely regulated, highly selective and relatively poorly understood process. Humans have the highest rate of miscarriage in mammals and various pharmacological manipulations have been used to minimize pregnancy losses in both spontaneous pregnancies and pregnancies resulting from assisted reproduction technology. The widespread application of protocols using numerous drugs in assisted reproduction treatment has led to an increasing number of pregnancies exposed to these drugs. The vast majority of these protocols have been based on data from a few observational and often retrospective clinical studies. This paper reviews the recent literature on drug interventions in early pregnancy after assisted reproduction treatment. It is concluded that there are still numerous issues about the safety of most drugs for both the women and their fetus. In many cases, the benefits are theoretical and the possible long-term side-effects are untested. There is an urgent need for more epidemiological studies and randomized controlled trials to explore the use, efficacy and side-effects of both old and new drugs in early pregnancy after assisted reproduction treatment.

Immunologic manipulation for the threatened fetus

Management of the pregnant woman with the antiphospholipid syndrome (APLS) has improved over the last 10 years. The recurrent pregnancy loss that is associated with this disease is managed with prophylactic low dose aspirin and heparin therapy. This therapy leads to a 40% absolute risk reduction in pregnancy loss. However, many women still fail to deliver a live infant despite this therapy so immunologic manipulation of the mother's disease in this group needs to be considered. Intravenous immunoglobulin and plasma exchange may have a role. New immunosuppressive drugs such as tacrolimus have yet to be tried. Monoclonal antibodies to B cells, B-cell growth factors, complement proteins and integrin molecules, all of which appear to play a role in the disease process, may also offer patients some hope. Similarly, biologics such as C1 esterase inhibitor protein, cell surface complement regulator proteins or interleukin-3 need to be tried given their efficacy in models of antibody-induced cell injury.

Heparin prevents antiphospholipid antibody-induced fetal loss by inhibiting complement activation

The antiphospholipid syndrome (APS) is defined by thrombosis and recurrent pregnancy loss in the presence of antiphospholipid (aPL) antibodies and is generally treated with anticoagulation therapy. Because complement activation is essential and causative in aPL antibody-induced fetal injury, we hypothesized that heparin protects pregnant APS patients from complications through inhibition of complement. Treatment with heparin (unfractionated or low molecular weight) prevented complement activation in vivo and in vitro and protected mice from pregnancy complications induced by aPL antibodies. Neither fondaparinux nor hirudin, other anticoagulants, inhibited the generation of complement split products or prevented pregnancy loss, demonstrating that anticoagulation therapy is insufficient protection against APS-associated miscarriage. Our data indicate that heparins prevent obstetrical complications in women with APS because they block activation of complement induced by aPL antibodies targeted to decidual tissues, rather than by their anticoagulant effects.

Effects of Low-Molecular-Weight and Unfractionated Heparin on Trophoblast Function

OBJECTIVE

Unfractionated and low-molecular-weight heparin and low-dose aspirin are used for the prevention of pregnancy loss in pregnant women with thrombophilia. We investigated the effect of these drugs on in vitro models of human extravillous trophoblast motility and differentiation.

METHODS

Chorion from term placentas was digested and extravillous trophoblast isolated. Extravillous trophoblast formed giant multinuclear cells that were counted after 24, 36, and 48 hours of culture. This model was then used to investigate the effect of unfractionated, low-molecular-weight heparin and aspirin on in vitro extravillous trophoblast differentiation at both therapeutic and supratherapeutic doses. In addition, the effect of unfractionated and low-molecular-weight heparin on hepatocyte growth factor-stimulated SGHPL-4 cell (extravillous trophoblast cell line) motility was determined by time-lapse microscopy.

RESULTS

At therapeutic doses unfractionated heparin promoted extravillous trophoblast differentiation. However, low-molecular-weight heparin inhibited giant multinuclear cells formation. At supratherapeutic doses, both low-molecular-weight and unfractionated heparin promoted extravillous trophoblast differentiation. Low-dose aspirin had minimal effects on the extravillous trophoblast differentiation. Both unfractionated and low-molecular-weight heparin inhibited hepatocyte growth factor-stimulated extravillous trophoblast motility at supratherapeutic doses. At a therapeutic dose of 0.25 IU/mL, only unfractionated heparin inhibited hepatocyte growth factor-stimulated motility, whereas low-molecular-weight heparin had no effect.

CONCLUSION

Our data suggest that unfractionated and low-molecular-weight heparin have differing effects on trophoblast differentiation and motility at therapeutic doses. This finding may be one of many factors that contribute to the clinical scenario.

Low molecular weight heparin in immunological recurrent abortion--the incredible cure

The most compelling association between pregnancy loss and autoimmune phenomena has been with the presence of antiphospholipid antibodies (APA)--lupus anticoagulant and anticardiolipin antibody. The 'antiphospholipid antibody syndrome' has been described in women with a history of recurrent pregnancy loss or thrombosis with positive APA or lupus anticoagulant on two occasions. Although several treatments have been advocated, heparin and aspirin treatment is emerging as the treatment of choice for the APA syndrome associated with recurrent pregnancy loss. The rationale for prescribing aspirin in cases of recurrent reproductive failure associated with APA seropositivity is that aspirin may counter APA-mediated hypercoagulability in the choriodecidual space, a situation which if left unaddressed would traumatize the trophoblast and compromise feto-maternal exchange. Heparin on the other hand, through preventing APA from interfering with syncytialization of the early cytotrophoblast and by countering APA interference with phospholipid-decidual reactions that are vital to early implantation, might potentially promote both early implantation and subsequent placentation.

Antiphospholipid antibodies: biological basis and prospects for treatment

Antiphospholipid antibodies (aPL) are autoantibodies that are associated with recurrent reproductive failure and thrombotic disease. There are two well-characterised aPL, lupus anticoagulant and anticardiolipin antibodies. aPL were originally thought to bind to negatively-charged phospholipids but it is now clear that the title aPL is a misnomer and that the antigens for these autoantibodies are actually phospholipid-binding proteins. Chief amongst these phospholipid-binding proteins are prothrombin and beta(2) glycoprotein I. This review concentrates on the role of beta(2) glycoprotein I in the reproductive failure caused by aPL. Exactly how aPL cause reproductive failure remains unknown but there is emerging evidence that the antibodies may have several different adverse effects on trophoblasts. There is also evidence questioning the traditional hypothesis that fetal demise is secondary to thrombosis of the utero-placental circulation. Heparin is commonly used to treat pregnant women with aPL but if these antibodies do not cause fetal demise primarily by a thrombotic mechanism a question must be raised over the role of heparin. However, heparin binds to many proteins including beta(2) glycoprotein I and it is possible that the reported beneficial effects of heparin in aPL-affected pregnancies may be due to the ability of heparin to prevent the interaction of aPL and beta(2) glycoprotein I.

Update on the management of the pregnant patient with antiphospholipid antibody

Management of the pregnant patient with antiphospholipid antibody (aPL) is reviewed, with emphasis on recent randomized controlled clinical trials. These support the use of subcutaneous heparin and low dose aspirin, current standard therapy for women with aPL and a history of fetal loss. Prednisone is rarely used due to high risk of maternal and fetal morbidity. Intravenous immunoglobulin may represent an important additional therapy for women who fail aspirin and heparin. Patients with a history of thrombosis require full, therapeutic anticoagulation during pregnancy. Recommendations are less clear for newly described antibodies to phospholipid-binding protein, for low titer antibodies, and for infertility treatment in the setting of aPL.

A literature review on the antiphospholipid syndrome and the effect on childbearing

OBJECTIVE

to review the literature on antiphospholipid antibodies and their significance to midwifery practice.

METHOD

databases using the keywords anticardiolipin antibodies, antiphospholipid antibodies, lupus antibodies, antiphospholipid syndrome, systemic lupus erythematosis, pregnancy loss, pre-eclampsia were searched, 548 articles were generated and 52 were used in the review.

FINDINGS

anticardiolipin antibodies are detrimental to successful pregnancy being implicated in failure of implantation, loss of the embryo and the fetus. There is also a risk of prematurity, intrauterine growth retardation and neonatal embolism. The risks to the mother are of pre-eclampsia and embolic complications. If diagnosed and treated early in pregnancy with low-dose aspirin and subcutaneous heparin the outlook for a successful pregnancy is much improved.

KEY CONCLUSIONS

much research remains to be undertaken. Researchers need to standardise their criteria so that findings are comparable and larger sample groups are necessary.

IMPLICATIONS FOR PRACTICE

antiphospholipid syndrome is an important disorder and a preventable cause of pregnancy loss. Midwives need to encourage women to persevere with therapy to preserve pregnancy and maybe prevent pre-eclampsia or thrombosis. When pregnancies are lost one of the hardest things is when the parents cannot understand why. Midwives need to understand the syndrome to collaborate with doctors in explaining it and supporting grieving parents.

Antiphospholipid syndrome and recurrent miscarriages

Sixty percent of recurrent spontaneous abortions are unexplained. Antiphospholipid syndrome is a multisystem disease with the predominant features of venous and arterial thrombosis, recurrent pregnancy loss, foetal death and the presence of antiphospholipid antibodies. Many epidemiological studies focus on antiphospholipid autoantibodies syndrome (APS) as a cause of recurrent spontaneous abortion (RSA). It is found that 7-25% of RSA would have APS as the main risk factor. 'Association not being synonymous with cause', the proportion of abortions due to the APS is difficult to estimate for several reasons: definition of recurrent abortion is variable, the assays for antiphospholipid antibodies are not well standardised, inclusion of patients in the study group according to the antibodies titre is author dependent. Recent studies suggest association of antiphospholipid antibodies syndrome not only with recurrent abortions but also with infertility. New mechanisms are described by which antiphospholipid antibodies could cause placental thrombosis and infarction, acting directly on the surface anticoagulant expressed on trophoblastic cells. Only lupus anticoagulant (LA) and anticardiolipin antibodies (aCL) assays are sufficiently standardised to be usable in routine. Testing for other antiphospholipid antibodies (aPLs) should remain investigational. Several treatments have been proposed: low doses of aspirin, low or immunosuppressive doses of corticosteroids, and preventive or effective dose of heparin, intravenous immunoglobulin.

Obstetric management of antiphospholipid syndrome

The obstetric management of women with antiphospholipid (aPL) syndrome remains controversial. Despite recent advances, the controversies have been fueled by our limited understanding of the multi-factorial causes of aPL-associated pregnancy loss and the lack of data from randomized studies. We have escaped from the narrow confines of the concept of aPL pregnancy loss being purely thrombotic in aetiology and attention is now focused on the adverse effects of aPL on embryonic implantation and trophoblast invasion. Combined treatment with aspirin and heparin has been demonstrated in two randomized studies to lead to a high live birth rate in aPL pregnancies. However, successful pregnancies are characterized by a high rate of perinatal complications and some women are refractory to this treatment combination. In addition to addressing these issues, multi-centre studies, which should perhaps be internet based, are needed to identify those aPL that are causative of pregnancy complications and those that are not, the role of IVIG and the long-term follow-up of both mothers with aPL and their babies.

The Antiphospholipid Syndrome in a Teenager with Miscarriages, Thromboses, and Diabetes Mellitus

The antiphospholipid syndrome has been associated with many clinical conditions since its description by GRV Hughes in 1983. The linkage to Type 1 diabetes mellitus has not been established. There have been no reports of deep venous thrombosis in association with antiphospholipid syndrome and diabetes mellitus. We present the case of an African-American teenager with multiple miscarriages, diabetic ketoacidosis, deep venous thromboses, and elevated immunoglobulin M and G anticardiolipin antibodies. We urge that clinicians consider testing for antiphospholipid antibodies when diabetic patients present with multiple miscarriages or deep venous thrombosis.

Interleukin-3 and human trophoblast: in vitro explanations for the effect of interleukin in patients with antiphospholipid antibody syndrome

OBJECTIVE

To examine the effect of interleukin (IL)-3 on in vitro trophoblast differentiation, hormone production, and invasiveness affected by antiphospholipid antibodies.

DESIGN

Primary cytotrophoblast cell cultures.

SETTING

Obstetrics and Gynecology Department of the Catholic University, Rome, Italy.

PATIENT(S)

Five normal pregnant women underwent uncomplicated vaginal delivery at 36 weeks of gestation.

INTERVENTION(S)

Immunoglobulin (Ig) G antibodies were isolated from the plasma of two patients with antiphospholipid syndrome and two normal control subjects with the use of protein-G Sepharose columns. Cytotrophoblast cells were dispersed in Ringer's bicarbonate buffer containing trypsin and DNAseI, filtered, and layered over a Percoll gradient in Hank's balanced salt solution.

MAIN OUTCOME MEASURE(S)

We investigated the effects of IL-3 and antiphospholipid antibodies on trophoblast cell invasiveness, differentiation, and hormone secretion.

RESULT(S)

IgG obtained from patients with antiphospholipid syndrome bound to trophoblast cells, with inhibitory effects on the cells' invasiveness, differentiation, and hCG secretion. IL-3 was able to restore in vitro placental functions.

CONCLUSION(S)

These results imply that IL-3 favorably affects human trophoblast implantation and development.

Habitual abortions in 678 healthy patients: investigation and prevention

The objective of this study of patients with habitual abortion (HA), was to determine their autoimmune profile and to try to prevent new abortions using low-dose aspirin for 7 months with prednisone in the first trimester only, or with low-dose aspirin alone. A total of 678 healthy patients with three or more HA were investigated for antiphospholipid antibodies, antinuclear and antithyroid antibodies. Among these patients, 277 pregnant women were treated, 214 were given prednisone and aspirin (161 autoantibody-negative and 53 autoantibody-positive women), and 63 autoantibody-negative women received aspirin alone. Autoantibodies were present in 33.9% of the patients, in 82.6% of them anticardiolipin antibodies were found to be isolated or associated with antiprothrombin, antithyroid, circulating anticoagulant, antinuclear or anti-beta2 glycoprotein 1 antibodies. In autoantibody-negative pregnant women treated by prednisone and aspirin or aspirin alone, the success rate of live births was 90.7% (146 out of 161) and 74.6% (47 out of 63) respectively (P < 0.01). In autoantibody-positive patients treated with prednisone and aspirin the success rate was 84.9% (45 out of 53) (not significant). Prednisone and aspirin seemed to be as efficient in autoantibody-negative or positive women but better than aspirin alone in autoantibody-negative women. A double-blind trial is in progress to confirm these results.

Low-molecular weight heparin restores in-vitro trophoblast invasiveness and differentiation in presence of immunoglobulin G fractions obtained from patients with antiphospholipid syndrome

The present study was designed to investigate the effects of immunoglobulin G obtained from patients with antiphospholipid syndrome (APS) on in-vitro models of trophoblast invasiveness and differentiation. We tested the binding of affinity-purified immunoglobulin G to human primary trophoblast cells. These antibodies affected the invasiveness and differentiation of cytotrophoblast cells after binding to the cell surface. In addition, we determined whether the drugs used to treat APS might be able to restore the trophoblast functions. Low-molecular weight heparin, in a dose-dependent manner, significantly reduced the immunoglobulin G binding to trophoblast cells and restored in-vitro placental invasiveness and differentiation. No effect was observed in the presence of acetylsalicylic acid. These observations may help in understanding the role of these treatments in women with APS.

Pregnancy complications in women with recurrent miscarriage associated with antiphospholipid antibodies treated with low dose aspirin and heparin

OBJECTIVE

To study the obstetric course of women with a history of recurrent miscarriage associated with antiphospholipid antibodies, lupus anticoagulant and anticardiolipin antibodies, treated with low dose aspirin and low dose heparin.

DESIGN

Prospective observational study.

SETTING

University based tertiary referral clinic.

POPULATION

One hundred and fifty pregnant women with a history of recurrent miscarriage associated with persistently positive tests for antiphospholipid antibodies.

METHODS

Lupus anticoagulant was detected using the dilute Russell's viper venom time together with a platelet neutralisation procedure. IgG and IgM anticardiolipin antibodies were detected using a standardised enzyme linked immunosorbent assay. An IgG anticardiolipin level > or = 5 per litre units and an IgM anticardiolipin level > or = 3 per litre units was considered positive. Aspirin (75 mg daily) was commenced at the time of a positive pregnancy test and heparin (5000 units subcutaneously 12 hourly, or enoxaparin 20 mg daily) was started when fetal heart activity was demonstrated on ultrasound. Treatment was stopped at the time of miscarriage or at 34 weeks of gestation.

RESULTS

One hundred and seven pregnancies (71%) resulted in a live birth. Forty-one pregnancies (27%) miscarried, the majority in the first trimester. One woman had a stillbirth, and one a premature baby who died in the neonatal period. One pregnancy was terminated for a fetal anomaly. Gestational hypertension complicated 17% (18/108) of ongoing pregnancies and antepartum haemorrhage 7% (8/108). Twenty-six babies (24%) were delivered before 37 weeks of gestation. Fifty women (46%) were delivered by caesarean section. The median birthweight of all live born infants was 3069 g (range 531-4300); however 15% (16/108) of the infants were small for gestational age.

CONCLUSION

Combination treatment with aspirin and heparin leads to a high live birth rate among women with recurrent miscarriage and antiphospholipid antibodies. However, successful pregnancies are prone to a high risk of complications during all trimesters. Close antenatal surveillance and planned delivery of these pregnancies in a unit with specialist obstetric and neonatal intensive care facilities are indicated.

Pregnancy loss and antiphospholipid antibodies

With the use of low-dose heparin, fetal survival of aPL pregnancies is 70-80%, but prematurity and intrauterine growth restriction are common. It is likely, but not proven, that dysregulated placental coagulation and resultant vasculopathy are the cause of fetal loss. Details of dysregulated coagulation remain to be described. Opportunities remain to determine the role of coagulopathy in repeated pregnancy loss, identify a critical event or window to which intervention might be directed, identify maternal (and fetal) characteristics other than aPL that determine fetal loss, describe toxicity profiles of current treatments, develop more specific, less toxic therapies, and describe long-term fetal and maternal outcomes.