Pregnancy outcome in women with antiphospholipid antibodies

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.

Thyroid antibodies and their relation to antithrombin antibodies, anticardiolipin antibodies and lupus anticoagulant in women with recurrent spontaneous abortions (antithyroid, anticardiolipin and antithrombin autoantibodies and lupus anticoagulant in habitual aborters)

OBJECTIVE

This study was undertaken to evaluate the incidence of thyroid autoantibodies in women with a history of recurrent spontaneous abortions (RSA) and to investigate their relationship to non-organ specific autoantibodies.

STUDY DESIGN

28 euthyroid non-pregnant habitual aborters were analysed for thyreoglobulin (TG), thyroid peroxidase antibodies (TPO), and autoantibodies to thromboplastin, cardiolipin and lupus anticoagulant. 28 multigravidae without previous abortions or endocrine dysfunctions served as controls.

RESULTS

11 of 28 women with recurrent spontaneous miscarriage (39%), but only 2 of 28 controls (7%) (Chi square test: p < 0.01) demonstrated positive titres of TG, TPO, or both antibodies, 12 patients were positive for antithrombin antibodies and 3 for anticardiolipin. Only one women was lupus anticoagulant positive. No significant correlation between thyroid antibody positivity and positivity for antiphospholipids (Fisher's exact test: p = 0.441), anticardiolipin (p = 0.664) or lupus coagulant (p = 0.607) was found.

CONCLUSIONS

The incidence of thyroid antibodies in euthyroid women with recurrent pregnancy loss appears to be significantly increased compared with controls of reproductive age without previous abortions. No correlation between the presence of thyroid autoantibodies and non-organ specific autoantibodies could be established.

Pathogenesis and treatment of the antiphospholipid antibody syndrome

Antiphospholipid antibody syndrome (APS) is one of the most important causes of thrombophilia, presenting most often as venous or arterial thrombosis, recurrent pregnancy loss, or thrombocytopenia. Both the lupus anticoagulant and anticardiolipin antibody are associated with APS. The mechanism of the prothrombotic state is not understood, but may involve beta-2 glycoprotein 1 (a naturally occurring anticoagulant), platelet aggregation, the protein C pathway, or endothelial cell function. The current treatment recommendation, after a venous or arterial thrombosis, is high-intensity, long-term warfarin therapy.