The association between antiphospholipid antibodies and placenta mediated complications: a systematic review and meta-analysis

Background: The association between antiphospholipid antibodies (APLA) and placenta mediated pregnancy complications (pre-eclampsia, intrauterine growth restriction (IUGR), late fetal loss and placental abruption) remains controversial.

Methods: We performed a systematic review of published case-control, cohort and cross sectional studies (MEDLINE (1975 to 2009), EMBASE 16 (1980 to 2009) and all EBM Reviews (2009)) to evaluate the association between APLA and placenta mediated complications in untreated women without autoimmune diseases.

Results: Our search strategy identified 1207 potentially relevant studies. Twenty eight were included in the final analysis. LA was associated with pre-eclampsia (OR 2.34; 95% CI 1.18-4.64), IUGR (OR 4.65 95% CI 1.29-16.71) and late fetal loss (OR 4.73; 95% CI 1.08-20.81) amongst case-control studies and only with late fetal loss (OR 10.59 95% CI 1.87-59.88) amongst cohort studies. ACA were associated with pre-eclampsia (OR 1.52; 95% CI 1.05-2.20) and late fetal loss (OR 4.29; 95% CI 1.34-13.68) amongst case-control studies and only late fetal loss (OR 8.85 95% CI 1.84-42.50) amongst cohort studies. Finally, anti-B2 GP1 antibodies showed associations with pre-eclampsia (OR 19.14, 95% CI 6.34-57.77), IUGR (OR 20.03; 95% CI 4.59-87.43) and late fetal loss (OR 23.46, 95% CI 1.21-455.01) in two cohort studies.

Conclusion: APLAs appear to be associated with late fetal losses. However, the association between APLAs and other placenta mediated complications is inconsistent. LA is most strongly and consistently associated with placenta mediated complications. There are currently insufficient data to support a significant link between anti-B2 GP1 antibodies and pregnancy morbidity.