Pre-eclampsia and inherited thrombophilia: a reappraisal

Pre-eclampsia (P-EC) is a major cause of maternal and fetal morbidity and mortality. Inherited thrombophilia has been suggested to increase the risk of P-EC or may accelerate the pathophysiological process. In the past 20 years, numerous studies and meta-analyses have yielded contradictory results regarding the association between inherited thrombophilia and P-EC/hemolysis, elevated liver enzymes, low platelets syndrome. Although studies published until 2002 reported on an increased prevalence of inherited thrombophilia in pre-eclamptic women, most subsequent studies did not. Inconsistency of data may be due to numerous confounders such as ethnicity, different definitions of P-EC, severity of illness, and methods of testing. Mild P-EC is unlikely to be associated with thrombophilic gene defects, whereas severe and early-onset P-EC is significantly related to inherited and acquired thrombophilia. Thrombophilic patients with severe P-EC appear to have an increased risk of overall maternal morbidity and recurrences of P-EC compared with pre-eclamptic women without thrombophilia. It remains a matter of debate if women with a previous history of (severe) P-EC should be screened for inherited thrombophilias and if the administration of low molecular weight heparin should be recommended in women with positive results to prevent adverse outcomes in subsequent pregnancies. Large prospective studies are urgently needed to determine the benefits and risks of prophylactic strategies.