Endocrine Abstracts

Introduction: Conn’s syndrome is a well-known cause of secondary hypertension; however, its association with pregnancy is rare. We discuss an interesting case of Conn syndrome presented with severe hypertension 8 weeks post-partum.

Case report: A 34-years-old lady, previously fit and well, presented with severe hypertension (blood pressure–189/115 mmHg) and hypokalaemia (K-2.5 mmol/l) at 8 weeks post-partum. Antenatal records indicated she was normotensive throughout her pregnancy and had an uneventful delivery. She did not have family history of hypertension. She was not on any prescribed or over the counter medications and denied liquorice sweet consumption. Her BMI was 26 kg/m² and had no clinical features of Cushing’s syndrome. Serum potassium was consistently low (2.5 mmol/l). Repeated measurements of renin and aldosterone showed undetectable renin <5 mu/l and high aldosterone between 828–1224 pmol/l. 24-hour urinary free cortisol was normal at 126 nmol/24 hrs. (reference range <165 nmol/l). Overnight dexamethasone suppression test showed appropriately suppressed cortisol of 18 nmol/l. Urinary met adrenalines were normal. Confirmatory biochemical test was not done as screening tests were strongly positive and patient had persistent hypokalaemia. MRI scan of the adrenals showed a 13×9 mm fat containing left adrenal adenoma. Adrenal vein sampling performed after correcting serum potassium showed a clear left side lateralisation and contralateral suppression (aldosterone/cortisol ration on the left was 18.4 and on the right was 0.3 with lateralisation index >60 ). She was treated with Ramipril 7.5 mg, Spironolactone 100 mg and Sando-K- 2 tablets twice a day and listed for urgent left adrenalectomy. Her blood pressure and potassium were well controlled on these medications.

Discussion and learning points: Hyperaldosteronism in pregnancy is associated with adverse maternal and foetal outcomes and hypertension is likely to be worsened in this period. Our case highlights an exceptional clinical scenario where Conn’s syndrome was likely masked during pregnancy with no evident physiological consequences on mother and foetus. Review of the literature suggests that increased progesterone during pregnancy in some people may mask the effects of hyperaldosteronism 1. Therefore, symptoms are evident in these people after the child birth and women may present with post-partum hypertension1. Clinicians should be aware of the possibility of Conn’s syndrome as a cause of post-partum hypertension especially when it is associated with hypokalaemia.

Reference: 1. Bretherton I, Pattison D, Pattison S, Varadarajan S. An Endocrine Cause of Acute Post-partum Hypertension. Obstet Med. 2013;6(1):30-32. doi:10.1258/OM.2012.120012