A 28-year-old woman is evaluated during a follow-up visit for elevated blood pressure measurements during pregnancy. She is at 12 weeks' gestation of her first pregnancy. She feels well, and the pregnancy has been otherwise uncomplicated. She did not have routine medical care before her pregnancy. Family history is significant for hypertension in her father and sister. Her only medication is a prenatal vitamin.
On physical examination, blood pressure is 155/95 mm Hg; other vital signs are normal. Funduscopic, neurologic, and cardiac examinations are normal.
Laboratory studies are normal.
Which of the following is the most likely cause of this patient's elevated blood pressure?
A. Chronic hypertension
B. Gestational hypertension
C. Normal physiologic changes in pregnancy
MKSAP Answer and Critique
The correct answer is A. Chronic hypertension. This content is available to MKSAP 18 subscribers as Question 62 in the Nephrology section. More information about MKSAP is available online.
The most likely diagnosis in this pregnant patient is chronic hypertension. Hypertension first recognized during pregnancy at <20 weeks' gestation usually indicates chronic hypertension. The American College of Obstetricians and Gynecologists (ACOG) defines chronic hypertension as a systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg starting before pregnancy or before 20 weeks of gestation or persists longer than 12 weeks' postpartum. In normal pregnancy, the blood pressure declines during the first trimester, reaches its lowest level in the second trimester, and rises slowly thereafter. A patient with hypertension in the first trimester suggests that the hypertension predates the pregnancy. To avoid overtreatment of hypertension and associated fetal risk, the 2013 ACOG guidelines recommend treating persistent systolic blood pressure ≥160 mm Hg or diastolic blood pressure ≥105 mm Hg in women with chronic hypertension. Blood pressure goals with medications are 120 to 160/80 to 105 mm Hg. Antihypertensive treatment reduces the risk of progression to severe hypertension by 50% compared with placebo but has not been shown to prevent preeclampsia, preterm birth, small size for gestational age, or infant mortality.
Gestational hypertension first manifests after 20 weeks of pregnancy without proteinuria or other end-organ damage and resolves within 12 weeks of delivery. This patient's early presentation is not consistent with gestational hypertension.
Normal physiologic changes in pregnancy are usually associated with decreased blood pressure in the first trimester with a nadir blood pressure in the second. In this patient, the high blood pressure is inconsistent with normal pregnancy changes.
Preeclampsia is defined clinically by new-onset hypertension and proteinuria that occur after 20 weeks of pregnancy. In addition to blood pressure criteria, there must be proteinuria or new-onset end-organ damage, including liver or kidney injury, pulmonary edema, cerebral or visual symptoms, or thrombocytopenia. This patient's early presentation in the first trimester and lack of end-organ involvement is not consistent with preeclampsia.
- The American College of Obstetricians and Gynecologists defines chronic hypertension as a systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg starting before pregnancy or before 20 weeks of gestation or persists longer than 12 weeks' postpartum.