Chapter 18 – Chronic Hypertension and Pregnancy

This chapter reviews presentation and management of chronic hypertension (primary and secondary) during pregnancy. Most gravidas have “essential” or primary hypertension and a>20% risk of superimposed preeclampsia but generally experience successful gestation. Essential hypertension, which in young women is often stage 1 (BP 140–150/90–99), may remain unrecognized because of the early physiological decrease in blood pressure, and then incorrectly labeled gestational hypertension or preeclampsia when frankly abnormal values appear after midgestation. Pheochromocytoma may be lethal and initially present during gestation. Contrarily, the hypokalemia and hypertension of aldosteronism are sometimes ameliorated by pregnancy because of the high circulating levels of progesterone which block the mineralocorticoid receptor, similar to spironolactone. Renal artery stenosis and Cushing syndrome are both associated with substantial morbidity, particularly if first diagnosed during pregnancy. Pregnancy changes in circulating levels of all components of the renin−angiotensin−aldosterone system and corticosteroids make diagnoses difficult, underscoring the need to develop test ranges for pregnancy. The status of antihypertensive drugs in pregnancy is reviewed.