REN and primary aldosteronism: In our study, the aldosterone excess group was defined as the top 25% of aldosterone concentrations, and when patients within this group were selected for declining renin activity over gestation (considering that suppressed renin activity is a feature of primary aldosteronism outside of pregnancy), there were 19 out of 128 patients, about 15%, which is consistent with current estimates of primary aldosteronism in the population.