Once you decide to expectantly manage a patient with preeclampsia, the balancing act begins. That means weighing fetal benefits against maternal risks, since the only justification for expectant management is to prolong pregnancy for fetal gain—there is no advantage to the mother.
The best approach is to classify the woman’s preeclampsia by the degree of severity and gestational age at the time of diagnosis, then follow recommendations tailored to that particular category.
This article offers guidelines for expectant management of mild and severe preeclampsia, preeclampsia superimposed on a preexisting medical condition, and intrapartum and postpartum care.
The earlier preeclampsia develops, the greater the risk it will become severe. The need for hospitalization depends on gestational age, blood pressure, proteinuria levels, maternal symptoms, and reliability of the patient.
Preeclampsia is mild when systolic blood pressure reaches 140 to 159 mm Hg or diastolic pressure measures 90 to 109 mm Hg on at least 2 occasions more than 6 hours apart after 20 weeks’ gestation in a woman who previously had normal blood pressure. In preeclampsia, this hypertension is accompanied by proteinuria of 0.3 to 4.9 g in a 24-hour urine sample (1+ or 2+ by dipstick on 2 occasions).
At or beyond 37 weeks’ gestation
In general, women diagnosed with preeclampsia at this gestational age have pregnancy outcomes similar to those of normotensive gravidas. Thus, they benefit from induction of labor and delivery.
32 to 36 weeks’ gestation
Close maternal and fetal evaluation is essential. (It is assumed these women have no labor or membrane rupture and normal fetal testing; otherwise, delivery is indicated at 34 weeks or beyond.)
In general, hospitalization is indicated when any of the following circumstances are present (FIGURE 1):
- the patient is unreliable,
- 2 or more systolic blood pressure readings exceed 150 mm Hg,
- 2 or more diastolic blood pressure readings exceed 100 mm Hg,
- proteinuria occurs at a rate exceeding 1 g/24 hours, or
- persistent maternal symptoms are present.
FIGURE 1 Treatment of mild preeclampsia in healthy women
Before 32 weeks’ gestation
These women are at high risk of progressing to severe disease. They also are more likely to have adverse perinatal outcomes such as intrauterine growth restriction (IUGR) (15% to 20%), preterm delivery (50%), and abruptio placentae (1% to 2%), compared with women diagnosed with preeclampsia at 32 to 36 weeks. In addition, they require more antenatal surveillance than women who develop preeclampsia later in pregnancy.
I recommend hospitalization at the time of diagnosis when women develop mild preeclampsia before 32 weeks.
What and when to monitor
Maternal evaluation should include:
- monitoring of blood pressure at least daily (at home or in the hospital),
- daily urine dipstick evaluation to monitor changes in proteinuria,
- twice-weekly platelet count and liver enzymes, and
- documentation of symptoms. (Instruct all women to report the onset of severe headaches, visual changes, altered mental status, epigastric or right upper quadrant pain, and any nausea or vomiting.)
Fetal evaluation should include:
- serial ultrasound every 3 weeks to estimate fetal weight and amniotic fluid status,
- nonstress testing every week, and
- daily fetal movement counts.
If a nonstress test is nonreactive, it should be confirmed by biophysical profile.
All testing should be promptly repeated if the maternal clinical condition deteriorates.
No need for bed rest, diuretics, or antihypertensive medications
Although expectantly managed patients with mild preeclampsia should be advised to restrict daily activity, there is no need for complete bed rest. Nor have diuretics or other antihypertensive drugs been shown to prolong gestation. On the contrary, these medications may mask severe preeclampsia.
Antihypertensive medications reduce the rate of severe hypertension but do not improve perinatal outcome. If these drugs are used to treat mild disease remote from term, hospitalize the patient and manage her as though she has severe preeclampsia.
Hospitalization versus outpatient management
Although she may be hospitalized at the time of diagnosis, a woman with preeclampsia may switch to outpatient management if systolic or diastolic blood pressure declines, proteinuria diminishes to 1 g/24 hours or less, and there are no maternal symptoms or evidence of severe IUGR. Otherwise, these women should remain hospitalized until delivery.