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HYPERTENSION IN PREGNANCY

Hypertensive disease complicates 6-8% of all pregnancies in the United States and is one of the major causes of maternal death. Hypertensive disease also significantly increases perinatal morbidity and mortality. Two distinct entities are commonly encountered in pregnant women: chronic hypertension and PIH. These two conditions may coexist; in fact, the risk of developing PIH is significantly increased in women with underlying chronic hypertension. Pregnancy-induced hypertension is a multiorgan disease process that may involve much more than elevated blood pressure. Sev-eral clinical subsets are recognized, depending on end-organ effects. Some such subsets have traditionally been given distinct labels, for example, preeclampsia when renal involvement leads to proteinuria, eclampsia when central nervous system involvement leads to seizures, and more recently, HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome when the clinical picture is dominated by hematologic and hepatic manifestations.

Clinical Manifestations

Hypertension is defined as a sustained blood pressure increase to levels of 140 mm Hg systolic or 90 mm Hg diastolic. Blood pressure may depend greatly on patient position; ideally, measurements should be taken in a uniform manner at each prenatal visit; the proper cuff size should be used.

Clinical Manifestations of Severe Disease in Patients with Pregnancy-Induced Hypertension

Blood pressure >160-180 mm Hg systolic or

>110 mm Hg diastolic

Proteinuria >5 g/24 h (normal <300 mg/24 h)

Elevated serum creatinine

Grand real seizures (eclampsia)

Pulmonary edema

Oliguria <500 mL/24 h

Microangiopathic hemolysis

Thrombocytopenia

Hepatocellular dysfunction (elevated alanine aminotransferase, aspartase).

Intrauterine growth restriction or oligohydramnios

Symptoms suggesting significant end-organ involvement: headache, visual disturbances, or epigastric or right-upper quadrant pain.

Pathophysiology

The etiology of PIH is unknown. However, it is well established that the disease process occurs most often in women who are pregnant for the first time, women with multiple gestation.

Clinical Management

Delivery is always an appropriate option in the term patient with hypertension. However, in the patient with an unfa-vorable cervix who exhibits only mild blood pressure elevations, minimal proteinuria, and no evidence of

Delivery should be considered in women who have signs and symptoms of severe PIH at 32-34 weeks of gestation..In some cases, the condition of women who initially manifest signs and symptoms of severe PIH will improve after observation and treatment with magnesium sulfate and various antihypertensive agents such as labetalol. In such women, continued observation is reasonable and appropriate at less than 32 weeks of gestation. If severe PIH recurs or does not respond to initial observation and therapy, delivery

Management of severe PIH at less than 28 weeks of gestation poses a difficult clinical dilemma because it is often unsuccessful and may be hazardous. Attempts at conservative management in women with severe PIH at 18-27 weeks of gestation have been associated with significant morbidity, including abruptio placenta.

Prevention

Several studies have addressed the use of low doses of aspirin for the prevention of PIH. A meta-analysis of six con-trolled trials demonstrated a significant reduction in IUGR and cesarean delivery in women judged to be at high risk for PIH based on various criteria. No reduction in perinatal death was seen.