Pre-eclampsia is a complex vascular disorder in pregnancy, characterised by new-onset hypertension after 20 weeks of gestation and proteinuria or new-onset signs of other maternal end-organ dysfunction. It affects 35 % of pregnancies. One of the most severe complications is eclampsia, which is a seizure occurring in association with pre-eclampsia. The aetiology of pre-eclampsia remains poorly understood, making strategies for its prevention challenging. Therefore, it is important to better understand the factors involved in its aetiology. The aim of this thesis was to evaluate the impact of several maternal and paternal background factors on the risk for pre-eclampsia and to investigate the incidence and outcomes of eclampsia in Finland.

In the first three substudies of this thesis the FINNPEC cohort (Finnish Genetics of Pre-eclampsia Consortium), collected from five Finnish university hospitals between 2008–2011 was studied. The participating women and men completed a questionnaire on their background information and serum samples were collected from a subset of women. For the fourth study, eclampsia diagnoses from 2006 to 2010 were retrieved from the national Medical Birth Register and the Care Register for Health Care.

In this thesis earlier age at menarche, subfertility, depression and non-communicable diseases were associated with increased risk of pre-eclampsia. Moreover, a family history of hypertension, stroke, diabetes and depression were risk factors. Socioeconomic status and physical activity during pregnancy were not related to pre-eclampsia. Physical activity of pre-eclamptic women and controls was not associated with the maternal serum concentrations of angiogenic factors. The phenotype and lifestyle of the partners did not play a significant role in pre-eclampsia susceptibility of parturients. The incidence of eclampsia in Finland was low, 1.5/10 000 deliveries, and it has decreased from the 1990s to the 2000s. Increased use of magnesium sulphate probably contributed to the low incidence as well as to the low number of recurrent seizures and prolonged complications.