For decades, we’ve known preeclampsia is a high-risk diagnosis with potentially serious consequences for both mother and fetus during pregnancy. Now we know it can have cardiovascular effects on women 20 to 30 years after delivery—effects severe enough to increase the mortality rate in these women. Clearly, preeclampsia is no longer just an obstetrics (OB) concern. Any nurse who works with adult women in their 40s and beyond must become aware of its implications.
Affecting about 5% to 8% of deliveries in the United States, hypertensive disorders of pregnancy are among the three leading causes of maternal death (along with hemorrhage and infection). From 1991 to 1997, preeclampsia caused 16% of 3,201 pregnancy-related deaths. (See Maternal survival after preeclampsia.)
Pathophysiology
The definitive cause of preeclampsia (formerly called toxemia or pregnancy-induced hypertension) remains unknown. However, the following conditions have been linked to its development:
• first pregnancy (first exposure to placental chorionic villi)
• exposure to unusually high levels of chorionic villi (as in multiple gestations or hydatidiform mole)
• preexisting vascular disease
• genetic predisposition to hypertension during pregnancy.
Besides affecting the placenta, preeclampsia may adversely affect every maternal body system. Fetal outcome depends on disease severity and gestational age at delivery. Fetal effects may include intrauterine growth restriction, preterm birth and its complications, stillbirth, and hypoxia or death secondary to abruptio placentae. The only true resolution of preeclampsia is delivery of the fetus and placenta.
Preeclampsia occurs when a previously normotensive pregnant woman has a systolic pressure of 140 mm Hg or higher and a diastolic pressure of 90 mm Hg or higher, along with a urine protein level exceeding 300 mg in a 24-hour specimen. Other laboratory findings may include abnormal liver enzyme levels and renal function test results and a low platelet count.In severe preeclampsia, clinical findings also may include oliguria, headache, altered mental status, cerebral and visual changes, right upper-quadrant or epigastric pain, hepatic impairment, thrombocytopenia, and fetal growth restriction. (See Ruling out similar disorders.)
What about edema?
Edema commonly accompanies preeclampsia and used to be considered part of preeclampsia’s diagnostic triad (along with hypertension and proteinuria). However, in pregnant women with hypertension and proteinuria, preeclampsia now is diagnosed even when edema is absent.
Researchers recently have linked preeclampsia to maternal illness and death long after the postpartal period—even in women who regained normal blood pressure after delivery. Although a 1976 study found that a history of preeclampsia didn’t increase the risk of cardiovascular disease (CVD), more recent research shows the disorder does raise the risk of later hypertension, CVD, and death.In a 2005 retrospective study by Funai et al, researchers found that in women who’d regained normal blood pressure after delivery, CVD mortality didn’t rise until 30 to 40 years after the preeclamptic pregnancy. This study divided subjects into three groups:
• group 1: those who hadn’t experienced preeclampsia (35,991 subjects)
• group 2: those who’d experienced preeclampsia but were later normotensive (479 subjects)
• group 3: those who’d experienced preeclampsia with a subsequent pregnancy or who hadn’t had a subsequent pregnancy (591 subjects).
CVD has become the number-one killer of women, and women account for 51% of CVD deaths. Now that preeclampsia has been identified as a CVD risk factor, nurses need to take an active role by identifying at-risk women. Teach preeclamptic patients about their increased risk of future hypertension and its possible consequences. Inform them they’re at higher risk for CVD and increased mortality in their 40s and 50s, whether or not their blood pressure returns to normal after delivery.Even if you work in a non-OB setting, inform any patient with a history of preeclampsia that she’s at high risk for CVD and increased mortality, even if her blood pressure dropped to within normal limits after delivery. Assess her for additional risk factors and urge her to make follow-up appointments for regular assessment. Teach her about signs and symptoms of CVD—especially those specific to women. As appropriate, recommend dietary changes, weight loss or control, exercise, smoking cessation, and stress reduction. Encourage her to get screened for thrombophilia, insulin resistance, hyperlipidemia, and hypercholesterolemia.
American College of Obstetricians and Gynecologists. Diagnosis and management of preeclampsia and eclampsia. ACOG Practice Bulletin. No. 33, January 9, 2002.
