A 38-year-old woman comes to the office to discuss management of hypertension. She has chronic hypertension, which is managed with a stable dose of chlorthalidone. The patient is nulligravid but is currently contemplating pregnancy within the next year. She is a lifetime nonsmoker and does not use alcohol or illicit drugs. The patient's mother was diagnosed with hypertension at age 35. Blood pressure is 130/81 mm Hg; repeat blood pressure is 128/77 mm Hg. BMI is 26 kg/m². Physical examination is unremarkable. Laboratory results are as follows: Which of the following is the best advice to this patient?

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11ec25c8_d245_5a49_bc81_3dd3c9db68d4_MD0003_00 In pregnancy, chronic (preexisting) hypertension is hypertension diagnosed prior to or during the first 20 weeks gestation or persisting >12 weeks postpartum. Chronic hypertension confers an increased risk of maternal and fetal complications (eg, superimposed preeclampsia, preterm birth) and may require antihypertensive therapy (eg, to reduce the risk of maternal stroke in severe range hypertension [ie, systolic ≥160 mm Hg, diastolic ≥110 mm Hg]). First-line antihypertensive therapy in nonpregnant patients includes thiazide diuretics, calcium channel blockers, and ACE inhibitors (or angiotensin II receptor blockers). However, some medications are contraindicated (ie, teratogenic) or poorly studied in pregnancy; therefore, women who are pregnant or considering pregnancy should be changed to one safe for use in pregnancy. This patient who is planning pregnancy should have her medication changed to extended release nifedipine, a calcium channel blocker safe for use in pregnancy. Immediate release nifedipine may cause rapid drops in blood pressure, and other calcium channel blockers (eg, amlodipine, diltiazem) are not well-studied and therefore are typically not used. Other first-line options in pregnancy include methyldopa and labetalol. If after conception, the patient's blood pressure decreases significantly due to physiologic pregnancy adaptations (eg, decreased systemic vascular resistance), the medication may be reduced or discontinued. (Choice A) Spironolactone crosses the placenta and has potential antiandrogenic effects on male fetuses and is therefore not recommended for women who are pregnant or planning pregnancy. (Choice B) Thiazide diuretics (eg, chlorthalidone) are generally avoided during pregnancy due to risks of decreased maternal blood volume and potential for reduced placental perfusion. They are second-line agents, sometimes continued in patients who are already pregnant and were taking them prior to pregnancy (as most volume loss occurs in the first 2 weeks of pregnancy). Patients considering pregnancy should be switched to a first-line agent. (Choice C) Beta blockers that are safest in pregnancy include labetalol, pindolol, and long-acting metoprolol. However, for nonpregnant patients with hypertension and no other indications (eg, coronary artery disease), beta blockers are not recommended as first-line therapy because they are associated with less reduction in risk of stroke and mortality compared to other agents. In addition, atenolol is avoided in pregnancy because it is associated with lower birth weight. (Choice E) Both ACE inhibitors (eg, lisinopril) and angiotensin II receptor blockers (eg, valsartan) are contraindicated throughout pregnancy due to risks of fetal kidney dysfunction and subsequent oligohydramnios (eg, pulmonary hypoplasia). Educational objective: Women with chronic hypertension who are pregnant or considering pregnancy should be managed with a medication safe for use in pregnancy. Extended release nifedipine is a well-tolerated calcium channel blocker that can be used in nonpregnant patients and safely continued into pregnancy. References: Drug treatment of hypertension in pregnancy. (http://www.ncbi.nlm.nih.gov/pubmed/24554373) Impact of antihypertensive treatment on maternal and perinatal outcomes in pregnancy complicated by chronic hypertension: a systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/28515115)

A 38-Year-Old Woman Comes to the Office to Discuss Management