These results indicate that Caucasian women with a recent history of early-onset pre-eclampsia have a worse periodontal condition, as compared with women with uncomplicated deliveries.

A literature search of PubMed, EMBASE and CINAHL until August 2010 revealed 12 eligible observational studies and three randomized-controlled trials (RCTs). It appeared difficult to compare these studies, due to variations in definitions of periodontal disease and pre-eclampsia, timing of periodontal examination and inadequate control for confounding factors. Eight observational studies reported a positive association, while four studies found no association. None of the RTCs reported reductions in pre-eclamptic rate after periodontal therapy during pregnancy. Therefore, it is questionable whether periodontal disease plays a causal role in the pathogenesis of pre-eclampsia. The observed association in eight observational studies might be the result of induction of periodontal disease due to the pre-eclamptic state or it may be an epiphenomenon of an exaggerated inflammatory response to pregnancy. Larger RCTs with pre-eclampsia as the primary outcome and pathophysiological studies are required to explore causality and to dissect biological mechanisms involved.