However, these studies failed to select patients with pathological plasma renin activity levels, contained relatively few female patients, did not account for the confounding effects of other co-administered HF medications, used higher dose DRIs that affect renin as well as Ang II production, and commenced treatment late (e.g., initiation at Stage C rather than during Stage B) [34,35,36,37]. Here, REN is linked to hydrops fetalis.