Abnormal blood biomarkers in early pregnancy are associated with preeclampsia: a meta-analysis

Objective: Our aim was to evaluate the strength of association between abnormal levels of first trimester maternal blood biomarkers and the risk of preeclampsia.

Study design: We searched MEDLINE, EMBASE and Cochrane databases from inception until April 2013. Studies that assessed the association between any abnormal maternal blood biomarker in the first trimester and preeclampsia were included. Two independent reviewers selected studies, extracted data and assessed the quality. Results were summarized as pooled odds ratios with 95% confidence intervals.

Results: From 1071 citations, we identified 30 studies (65,538 women) for inclusion. Twenty four studies assessed preeclampsia of any onset, 10 studied early onset preeclampsia and seven evaluated late onset preeclampsia (after 34 weeks of gestation). The biomarkers PAPP-A (OR 2.1, 95% CI 1.6, 2.6), PP13 (OR 4.4, 95% CI 2.9, 6.8), sFlt-1 (OR 1.3, 95% CI 2.9, 6.8), pentraxin (OR 5.3, 95% CI 1.9, 15.0) and inhibin-A (OR 3.6, 95% CI 1.7, 7.6) were significantly associated with any preeclampsia. The odds of early onset preeclampsia were significantly increased when the biomarkers PlGF (OR 3.4, 95% CI 1.6, 7.2), PAPP-A (OR 4.8, 95% CI 2.5, 22.5), PP13 (OR 7.5, 95% CI 2.5, 22.5), soluble endoglin (OR 18.5, 95% CI 8.4, 41.0) and inhibin-A (OR 4.1, 95% CI 1.9, 8.8) were abnormal. Two biomarkers, soluble endoglin (OR 2.1, 95% CI 1.9, 2.4) and inhibin-A (OR 1.9, 95% CI 1.4, 2.8) were significantly associated with late onset preeclampsia.

Conclusion: Abnormal maternal blood biomarkers in early pregnancy are significantly associated with preeclampsia, particularly early onset disease.