Diagnosing Pre-Eclampsia

Diagnosing Preeclampsia in Family Practice Setting

Complications of hypertension are the third leading
cause of pregnancy-related deaths, superseded only by
hemorrhage and embolism. Preeclampsia is associated
with increased risks of placental abruption, acute renal
failure, cerebrovascular and cardiovascular
complications, disseminated intravascular coagulation,
and maternal death. Consequently, early diagnosis of
preeclampsia and close observation are imperative.

Diagnostic criteria for preeclampsia include new onset
of elevated blood pressure and proteinuria after 20
weeks of gestation. Features such as edema and blood
pressure elevation above the patient's baseline no
longer are diagnostic criteria. Severe preeclampsia is
indicated by more substantial blood pressure elevations
and a greater degree of proteinuria. Other featuresof
severe preeclampsia include oliguria, cerebral or visual
disturbances, and pulmonary edema or cyanosis.
Diagnosis becomes less difficult if physicians understand
where preeclampsia "fits" into the hypertensive
disorders of pregnancy. These disorders include chronic
hypertension, preeclampsia-eclampsia, preeclampsia
superimposed on chronic hypertension, and gestational
hypertension.

Diagnosis

Chronic hypertension is defined by elevated blood
pressure that predates the pregnancy, is documented
before 20 weeks of gestation, or is present 12 weeks
after delivery. In contrast, preeclampsia-eclampsia is
defined by elevated blood pressure and proteinuria that
occur after 20 weeks of gestation. Eclampsia, a severe
complication of preeclampsia, is the new onset of
seizures in a woman with preeclampsia. Eclamptic
seizures are relatively rare and occur in less than 1
percent of women with preeclampsia.

Preeclampsia superimposed on chronic hypertension is
characterized by new-onset proteinuria (or by a sudden
increase in the protein level if proteinuria already is
present), an acute increase in the level of hypertension
(assuming proteinuria already exists), or development
of the HELLP (hemolysis, elevated liver enzymes, low
platelet count) syndrome.

Gestational hypertension is diagnosed when elevated
blood pressure without proteinuria develops after 20
weeks of gestation and blood pressure returns to normal
within 12 weeks after delivery. One fourth of women
with gestational hypertension develop proteinuria and
thus progress to preeclampsia.

Physical Examination

Blood pressure should be measured at each prenatal
visit. As mentioned previously, increases above the
patient's baseline (greater than 30 mm Hg systolic or 15
mm Hg diastolic) are no longer considered to be criteria
for the diagnosis of preeclampsia. However, such
increases warrant close observation. To ensure
accurate readings, an appropriate-size blood pressure
cuff should be used, and blood pressure should be
measured after a rest period of 10 minutes or more.
During the blood pressure measurement, the patient
should be in an upright or left lateral recumbent position
with the arm at the level of the heart.

Fundal height should be measured at each prenatal visit
because size less than dates may indicate intrauterine
growth retardation or oligohydramnios. These conditions
may become apparent long before diagnostic criteria for
preeclampsia are met. Increasing maternal facial edema
and rapid weight gain also should be noted because fluid
retention often is associated with preeclampsia.
Although these symptoms (e.g., facial edema, rapid
weight gain) are not unique to preeclampsia, it is wise
to follow affected patients for hypertension and
proteinuria. Edema involving the lower extremities
frequently occurs during normal pregnancy and
therefore is of less concern.

Thorough Review of Preeclampsia...
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