Test your medicine knowledge with the MKSAP challenge, in partnership with the American College of Physicians.

A 38-year-old woman is evaluated during a follow-up visit. She has a history of well-controlled hypertension and type 1 diabetes mellitus. She is at 16 weeks’ gestation with her first pregnancy. Prior to conception she was taking lisinopril, which was discontinued in anticipation of the pregnancy, and labetalol was initiated. Other medications are insulin glargine, insulin lispro, and a prenatal vitamin.

On physical examination, she appears in good health. Blood pressure is 135/80 mm Hg. There is no edema. The remainder of the physical examination is normal.

Laboratory studies reveal a serum creatinine level of 0.7 mg/dL (61.9 µmol/L) and a urine protein–creatinine ratio of 0.8 mg/mg.

Which of the following is the most appropriate step in the management of this patient’s hypertension?

A: Add methyldopa
B: Change labetalol to losartan
C: Increase labetalol dose
D: Continue current medication regimen

MKSAP Answer and Critique

The correct answer is D: Continue current medication regimen.

For this pregnant patient with chronic hypertension, continuation of her current medication regimen is appropriate. Prior to conception, her medication was changed to labetalol, which is considered first-line therapy for the management of hypertension during pregnancy. This patient has a normal serum creatinine level but has proteinuria. She previously had been on an ACE inhibitor, which decreases proteinuria. Proteinuria is typically increased during pregnancy in patients with preexisting proteinuria. There is an increase in the glomerular filtration rate (GFR) related to the increase in plasma volume, yet this increase in GFR is not matched by an increase in tubular absorption of proteins; therefore, an increase in proteinuria follows. If this patient were not pregnant, strict blood pressure goals would be applied with blockade of the renin-angiotensin-aldosterone system. In contrast, blood pressure goals in pregnancy have not been rigorously tested; instead, management is focused on avoiding end-organ damage in the mother during this finite period. Although there are slight differences in the antihypertensive goals from various professional societies, most agree that the blood pressure should be less than 150/100 mm Hg. Currently, this patient’s blood pressure is well within the target for management of chronic hypertension during pregnancy. Therefore, close monitoring and follow-up are indicated.

Although methyldopa is an acceptable medication with an established safety history for use in pregnancy, it frequently has a sedating effect and often needs to be given three times daily for an adequate antihypertensive effect. Furthermore, because this patient has achieved a reasonable blood pressure goal, there is no indication for add-on therapy at present.

Exposure to ACE inhibitors or angiotensin receptor blockers such as losartan during the first trimester has been associated with fetal cardiac abnormalities; exposure during the second and third trimesters has been associated with neonatal kidney failure and death. These agents are considered pregnancy category X drugs and should be held until after delivery.

There is no reason to increase the labetalol at this time because she is at a reasonable blood pressure goal and is tolerating the current dose well.

Key Point

• Close monitoring and follow-up are indicated for pregnant patients who have chronic hypertension with blood pressure measurements within target goals.

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