Fish Oil Trials in Pregnancy for the Prevention of Pregnancy Complications ('FOTIP')

Inclusion Criteria: * There were six subgroups with different inclusion criteria: * The low dose (prophylactic) section enrolled women who after 16 weeks of gestation had been identified with an uncomplicated pregnancy, who in an earlier pregnancy had experienced preterm delivery (this was subgroup 1) * Intrauterine growth retardation (subgroup 2) or pregnancy induced hypertension (subgroup 3) * Women who had been identified with twin pregnancies (subgroup 4) * The high dose ('therapeutic') section enrolled women with threatening pre-eclampsia (subgroup 5) or suspected intrauterine growth retardation in the current pregnancy (subgroup 6). Exclusion Criteria: * Diabetes mellitus in or before pregnancy * Diagnosed severe fetal malformation or hydrops in current pregnancy * Suspicion in current pregnancy, or occurrence in an earlier pregnancy, of placental abruption * Drug or alcohol abuse * Regular intake of fish oil or of non-steroidal antiinflammatory agents or other drugs with an effect on thombocyte function or eicosanoid metabolism * Allergy to fish products.