Primary hyperaldosteronism in pregnancy.

We report a case of primary hyperaldosteronism in a 37-year-old woman presenting early in pregnancy with hypertension and hypokalaemia. Plasma renin concentration was suppressed and unaffected by sodium restriction or upright posture at 16 and 35 weeks gestation, or seven days post-partum. Recumbent plasma aldosterone was elevated, and normal postural response lost both at 35 weeks gestation and seven days post-partum. Vaginal delivery, following induction at 38 weeks, was uncomplicated. Two months postpartum C.T. scan and adrenal venous catheterisation studies indicated a left sided adenoma and left adrenalectomy was performed. Within seven days the patient was normotensive with normal serum potassium and urinary aldosterone on no treatment.