Activated protein C resistance shows an association with pregnancy-inducedhypertension

A common mutation in the factor V gene, the Leiden mutation, is the most fr equent genetic cause of resistance to activated protein C (APC), Recent stu dies have shown that the prevalence of APC resistance is associated with se vere pregnancy-induced hypertension (PIH). Our objective was to determine w hether the factor V Leiden mutation is more prevalent in patients who devel oped severe PIH than in normotensive pregnant women. In 70 women with a his tory of severe PIH, of whom 15 had pre-eclampsia, we investigated common co agulation factors as well as APC resistance (factor V related). We found th at seven of these 70 women showed low values for APC, Out of these, five we re heterozygous and none was homozygous for factor V Leiden mutation. In a control group of normotensive pregnant women we found a 3.0% rate of APC re sistance and a 3.0% rate of carriers of the Leiden mutation. These results indicate a significantly higher prevalence of both APC resistance and facto r V Leiden mutation in women with severe PIH. Placental infarctions and mic ro-embolisms are considered to be one of the principle pathophysiological c hanges in severe PIH. Our results suggest that APC resistance is a risk fac tor for severe PIH, in addition to its well-known role in macrothrombo-embo lism.