Objectives: Offspring of hypertensive pregnancies have increased cardiovascular risk factors during childhood. We hypothesised that offspring of hypertensive pregnancies would demonstrate increased clinical levels of hypertension by young adult life, which would be proportional to the severity of the pregnancy complication. Design: Prospective birth cohort study Setting: Tertiary obstetric hospital. Participants: 2868 young adult offspring of women enrolled during pregnancy into the Western Australia Pregnancy Cohort (Raine) Study. Main outcome measures: Cardiovascular risk, including incidence of hypertension and metabolic disease, in those born to hypertensive compared to normotensive pregnancies. Results: Young adult offspring of hypertensive pregnancies were 2.5 times (95% CI 1.32 to 4.56, p=0.004) more likely to have global lifetime risk (QRISK) scores above the 75th centile. Thirty per cent of 20 year olds with hypertensive blood pressures were born following a hypertensive pregnancy. Pre-eclampsia or hypertension resulting in preterm birth associated with a threefold (95% CI 1.3 to 7.0, p=0.01) greater risk of being hypertensive by age 20 years, with no differences in body mass index. Whereas pregnancy-induced hypertension associated with a smaller 3±1 mm Hg blood pressure rise (p=0.001) and a twofold (95% CI 1.5 to 2.8, p=0.001) greater risk of being obese or overweight. Risk factor associations were consistent throughout early life and independent of other birth-factors. Conclusions: Incidence of offspring hypertension was significantly increased in those whose mothers had a more complicated pregnancy history, including preterm birth and pre-eclampsia.