Hyperaldosteronism in pregnancy

Abstract

Aldosterone is a key regulator of electrolyte and water homeostasis and plays a central role in blood pressure regulation. Hormonal changes during pregnancy, among them increased progesterone and aldosterone production, lead to the required plasma volume expansion of the maternal body as an accommodation mechanism for fetus growth. This review discusses the regulation of aldosterone production by aldosterone synthase (CYP11B2); the impact on aldosterone secretion due to the presence of a chimeric gene originating from a crossover between CYP11B1 and CYP11B2 in glucocorticoid remediable aldosteronism (GRA) - the inherited form of hypertension; enhanced aldosterone production in aldosterone-producing adenoma (APA); and idiopathic hyperaldosteronism (IHA). Features of hyperaldosteronism are also found in patients with apparent mineralocorticoid excess (AME), in which glucocorticoids exacerbate activation of the mineralocorticoid receptor (MR) because of a defect in the 11beta-hydroxysteroid dehydrogenase type 2 enzyme. Regulation of aldosterone production and tissue-specific activation of the mineralocorticoid receptor are prerequisites for optimal control of body fluids and blood pressure during pregnancy and contribute largely to the wellbeing of the mother-to-be.

An Endocrine Cause of Acute Post-partum Hypertension

“…A complex interplay of hormonal mechanisms stimulate the renin-angiotensin-aldosterone system (RAAS) including placental oestrogen and progesterone secretion, local placental RAAS production and decreased vascular resistance. 1 Plasma renin activity steadily increases from early pregnancy, reaching a peak at 20 weeks gestation with levels seven-fold higher than pre-pregnancy. 12 Aldosterone levels increase ten-fold during pregnancy, roughly tripling by the eighth week of gestation and peaking at 38 weeks.…”

“…In the majority of cases this is due to an adenoma of the adrenal cortex -Conn's syndrome. 1 Review of the literature, including…”

“…In the majority of cases this is due to an adenoma of the adrenal cortex-Conn's syndrome. 1 Review of the literature, including the review by Matsumoto et al 2 and subsequent reported cases, reveals 29 cases of primary aldosteronism associated with pregnancy. 29…”

High aldosterone, hypertension and adrenal adenoma in a 36-year-old pregnant patient: Is this primary aldosteronism?

“…Progesterone, increases 1000-fold during pregnancy and competitively binds to aldosterone receptors, which leading to a physiological elevation in aldosterone in healthy pregnancies. 5,[9][10][11][12] Additionally, the ovaries and placental tissues secrete renin, further raising renin and aldosterone levels. 5,10,12 Estrogen stimulates hepatic angiotensinogen production, again leading to down-stream up-regulation of aldosterone.…”

Hormonal Changes and Endocrine Testing in Pregnancy

“…146-13), a fivefold increase occurring by 16 weeks and ultimately a sevenfold to tenfold elevation occurring by term. 147 Significant correlation has been demonstrated between plasma aldosterone and plasma renin activity; plasma progesterone, plasma estriol, and plasma estradiol levels; and urine aldosterone levels. 145 In contrast, in pregnant women with gestational hypertension, plasma renin activity levels are higher than in normotensive nonpregnant women but do not increase during the pregnancy, whereas aldosterone levels are stable until the last trimester, when they rise.…”