Association of anticardiolipin antibodies with preeclampsia: a systematic review and meta-analysis

To systematically review the evidence of the association of anticardiolipin antibodies with preeclampsia.

PubMed and LILACS were perused up to June 2009, citations were searched using the ISI Web of Knowledge database, textbooks and reference lists were reviewed, and experts were contacted. Search terms included "antiphospholipid syndrome," "Hughes' syndrome," "anticardiolipin antibodies," "antiphospholipid antibodies," "anti-cardiolipin," "preeclampsia," and "pre-eclampsia."

Inclusion criteria were: cohorts, case-control, or controlled cross-sectional studies; healthy pregnancy as controls; no autoimmune diseases; immunoglobulin (Ig)G, IgM anticardiolipin antibody of at least 20 units by enzyme-linked immunosorbent assay, or both; and end-point preeclampsia.

Our search generated 68,528 entries and 64 full-text articles were reviewed. Twelve studies were included in the meta-analysis. Pooled odds ratio (OR) for association of anticardiolipin antibodies with preeclampsia was 2.86 (95% confidence interval [CI], 1.37-5.98). Pooled OR for anticardiolipin antibodies and severe preeclampsia was 11.15 (95% CI 2.66-46.75). Funnel plot showed minor asymmetry, and the Egger test was not significant (P=.359). Meta-regression identified study design and size as related to heterogeneity.

Moderate-to-high levels of anticardiolipin antibodies are associated with preeclampsia, but there is insufficient evidence to use anticardiolipin antibodies as predictors of preeclampsia in clinical practice.