Direct correlation between plasma renin activity and severity of the ovarian hyperstimulation syndrome

Plasma renin activity (PRA) and aldosterone were measured throughout the luteal phase in 21 anovulatory patients who developed ovarian hyperstimulation syndrome (OHSS) during menotropin induction of ovulation. The pattern of PRA in hyperstimulated cycles is characterized by a midluteal peak, which declines to normal in the late luteal phase in nonconceptual cycles, whereas a sustained elevation of PRA occurs in conceptual cycles. Midluteal PRA is significantly (P less than 0.001) elevated in patients with OHSS compared with controls. In the mild form of the disease, the median of PRA is 7.5 (range 6 to 11) ng angiotensin I (AI)/ml/hr, significantly higher than the median for controls, 3.0 ng AI/ml/hr (range, 1.4 to 5). In moderate OHSS, PRA was 24.5 (range, 10 to 40) ng AI/ml/hr, whereas, in the severe form of OHSS, PRA was 55.0 (range, 29 to 95) ng AI/ml/hr. A significant correlation (P less than 0.05) was demonstrated between PRA and either progesterone or 17 beta estradiol (E2). The renin-angiotensin cascade is implicated in new vessel formation. Angiogenesis itself is associated with a rapid increase in capillary permeability. The recent demonstration of high plasma renin-like activity in human follicular fluid and the present observation of high PRA in patients with OHSS may imply that the locally active renin angiotensin system, through induction of new vessel formation and increase in capillary permeability, may have a casual relationship to the ovarian enlargement and extracellular fluid accumulation that are the hallmarks of OHSS.