The main findings from this study are: (1) Aldosterone concentrations in serum greater than 704 pmol/L (the 75th percentile within cohort) were evident across all categories of hypertension in pregnancy, including normotensive; (2) systolic and diastolic blood pressures were highest in the top quartile of aldosterone concentration compared to the remaining quartiles, (3) especially when accompanied by declining renin activity, and this group was characterized by a high prevalence of chronic hypertension, use of anti-hypertensive agents, pre-term birth, and slightly higher prevalence of IUGR. Here, REN is linked to Hypertension.