Workup and Medical Management of Primary Aldosteronism during Pregnancy: A Case Report and Review of the Literature

Presentation Number: SUN-0793
Date of Presentation: June 22nd, 2014

Deirdre Cocks Eschler*, Aarti Ravikumar, Gillian M Goddard, Lawrence Krakoff and Alice C Levine
Icahn School of Medicine at Mount Sinai, New York, NY

Abstract

BACKGROUND: Uncontrolled hypertension in pregnancy can result in maternal and fetal morbidity and mortality.  Less than 40 cases have been reported to be a result of primary aldosteronism (PA).  We present the first report, to our knowledge, of PA in pregnancy responsive to spironolactone and illustrate the possible need for early surgical intervention.

CASE: A 25 year old nulliparous woman was admitted to the obstetrics unit at 23 weeks gestation for management of uncontrolled hypertension. She had a history of HTN diagnosed at age 17 and of hypokalemia while on a thiazide diuretic   A work-up for secondary HTN was initiated 5 weeks prior for recorded BPs in the 140-170s systolic despite labetalol 800 mg PO TID and nifedipine 60 mg PO TID.   24-hour urine free cortisol, metanephrine, and protein values and serum electrolytes and TSH were all normal. Upright aldosterone and renin values were 36 ng/dL and 1 ng/mL/hr respectively with an aldosterone to renin (ARR) ratio of 36 and repeated values on admission were 53 ng/dL and 1.2 ng/mL/hr respectively with an ARR ratio of 44. An MRI of the adrenals revealed an 8mm, lipid-rich left adrenal nodule, but as she entered her third trimester surgical exploration was no longer advisable. Despite maximal dose titration of Labetolol and Nifedipine BP remained 160/110.  An ultrasound revealed a female fetus.  Spironolactone 25mg PO BID was initiated.  A week later, her BP was 157/96 and spironolactone was increased to 50mg BID with a BP response to126/78 at 28 weeks gestation.  Unfortunately, due to possible medication adherence issues, the patient was admitted 1 week later with a BP of 205/147 and had an emergency C-section for possible HELLP syndrome. The baby is on a respirator in the NICU.

DISCUSSION: In the non-pregnant population, PA is mostly commonly due to bilateral adrenal hyperplasia and an ARR > 20 and a plasma aldosterone > 10 ng/dL with a suppressed renin signify a positive screen and warrant confirmatory testing.  PA in pregnancy, however, is most often caused by an adrenal adenoma and the diagnosis poses specific challenges due to the normal physiologic increases in both renin and aldosterone (with lack of gestational-specific reference ranges) as well as limitations in the use of confirmatory testing in pregnant women.  Suggestive features include severe hypertension, hypokalemia, and a suppressed renin.  Provided BP responds, most cases are managed medically with methyldopa, labetalol and/or calcium channel blockers (and eplerenone in a case report), with confirmatory testing and surgery deferred until postpartum.  This case is instrumental in showing that PA in pregnancy can be treated with the addition of spironolactone once the fetus is confirmed to be female and highlights the need for early, aggressive treatment and possibly even surgery.

 

Nothing to Disclose: DCE, AR, GMG, LK, ACL