About 25% of all pregnancies are complicated by gestational disease, of which severe hypertension (i.e. early preeclampsia and HELLP syndrome) and preterm labour are the leading cause of pregnancy-related maternal morbidity and mortality and poor neonatal outcome. Although there is consensus that the causal organ for these gestational diseases is the placenta the underlying multifactorial molecular causes and early and reliable clinical biomarkers that explain and predict development of obstetrical disease during the course of pregnancy are not available.