he diagnosis of chronic hypertension in pregnancy should be confirmed. The American College of Obstetricians and Gynecologists (2013) recommends use of ambulatory monitoring to exclude suspected white-coat hypertension before initiating antihypertensive therapy. Goals for chronic hypertension management include rate reductions of adverse maternal or perinatal outcomes just discussed. Treatment is targeted to prevent moderate or severe hypertension and to delay or dampen the severity of pregnancy-aggravated hypertension. To some extent, these goals can be achieved pharmacologically. Blood pressure self-monitoring is encouraged, but for accuracy, automated devices must be properly calibrated (Brown, 2004; Staessen, 2004). Personal health modification includes dietary counseling and reduction of behaviors such as tobacco, alcohol, cocaine, or other substance use (see Table 50-2). A low-sodium diet is not required (American College of Obstetricians and Gynecologists, 2013).
Some women-especially those with long-term or untreated hypertension-have complications that increase the risk of adverse pregnancy events. For example, in one study, a fourth of gravidas with chronic hypertension also had concentric ventricular hypertrophy (Ambia, 2017; Kim, 20 16a). Thus, if not already accomplished, assessment during pregnancy is done for the cardiovascular and renal systems (Morgan, 2016a,b).
As concluded by the American College of Obstetricians and Gynecologists (2013, 2016a), treatment of hypertension during pregnancy has included every drug class, but information is still limited regarding safety and eicacy (Czeizel, 2011; Podymow, 2011). lthough many studies indicate greater perinatal adverse efects in gravidas requiring treatment, it is still not known whether this is due to cause or efect (Orbach, 2013). The following summary of antihypertensive drugs is abstracted from several sources, including the 2016 Physicians' Desk Rf erence. Many of these drugs are also discussed throughout Chapter 12 (p. 241) and have been reviewed by Umans and associates (2015).
PeripheraLy acting 3-adrenergic-receptor blockers cause a generalized decline in sympathetic tone and decreased cardiac output. Examples are propranolol, metoprolol, and atenolol. Labetalol is a popular and commonly used QJ3-adrenergic blocker that is considered safe. Some adrenergic-blocking drugs act centraLy by reducing sympathetic outflow to efect a generalized decreased vascular tone. These include clonidine and a-methyldopa. Drugs in this class most frequently used in pregnancy to treat hypertension are methyldopa or an a-or 3-receptor blocking agent such as labetalol.
hese drugs are divided into three subclasses based on their modiication of calcium entry into cells and interference with binding sites on voltage-dependent calcium channels. Common agents include nifedipine-a dihydropyridine, and verapamil-a phenylalkyl amine derivative. These agents have negative inotropic efects and thus can worsen ventricular dysfunction and congestive heart failure. Theoretically, they may potentiate the vasoactive actions of magnesium sulfate that is given for eclampsia neuroprophylaxis. Although data are limited regarding their use during pregnancy, they appear to be safe therapy for chronic hypertension (Briggs, 2015; U mans, 2015).