Pre-eclampsia

Does this patient have pre-eclampsia?

How do you diagnose pre-eclampsia?

Preeclampsia is defined as the new onset of hypertension (BP > 140/90) and proteinuria (≥ 300 mg protein in a 24-hr urine collection) after 20 weeks of gestational. Hypertension plus other signs such as thrombocytopenia, elevated serum transaminase levels, or systemic organ failure is also sufficient for the diagnosis of preeclampsia in the absence of proteinuria. Preeclampsia effects 5-7% of all pregnancies and is responsible for approximately 60,000 maternal deaths every year, mainly in resource-poor countries.

Eclampsia is a life-threatening complication of preeclampsia and is characterized by grand mal seizures.

A severe variant of preeclampsia features hemolysis, elevated liver function tests, and low platelets (HELLP syndrome).

Proteinuria is a common feature of preeclampsia. Pathologically, the kidneys in women with preeclampsia exhibit glomerular endotheliosis, a manifestation of systemic extensive endothelial damage in preeclampsia.

Severe preeclampsia is defined as: Systolic blood pressure at least 160 mmHg or diastolic pressure of 110 mmHg, proteinuria of at least 5 g/24 h, platelet count below 100,000 /μL, elevated serum transaminases, oliguria, pulmonary edema, epigastric pain, or cerebral or visual disturbances

What tests to perform?

Blood pressure measurement, urine dipstick testing, protein/creatinine ratio in random sample of urine, complete blood count, liver function tests, uric acid, renal function tests, clotting studies. Fetal assessments with ultrasound, biophysical profile and nonstress test.

How should patients with pre-eclampsia be managed?

The only known cure for preeclampsia is delivery. If a patient is diagnosed with preeclampsia and is near term (>37 weeks), induction of labor is indicated. If the patient is preterm, admission to the hospital is considered and the pregnancy is closely monitored. In some instances glucocorticoids are given to promote fetal lung maturity.

Conservative management is continued as long as blood pressure remains well controlled and there are no significant laboratory abnormalities. There are multiple antihypertensives used in current clinical practice, which have proven to be of benefit in the treatment of hypertension in pregnant women including labetalol nifedipine, and methyldopa.

Delivery is considered at any stage of pregnancy if hypertension is severe and remains uncontrolled for 24-48 hours. Other indications for delivery include the presence of liver abnormalities, renal dysfunction, headache, epigastric discomfort, seizures or the presence of severe growth retardation or abnormal fetal testing.

Maternal and fetal clinical condition, gestational age, biochemical and hematological parameters remain the primary determinants for timing delivery in women with preeclampsia

Common indications for delivery before 34-35 week’s gestation are:

• Uncontrollable blood pressure

• Deteriorating renal function

• Pulmonary edema

• Persistent HELLP syndrome

• Deteriorating liver function

• Eclampsia

IV magnesium sulphate is used to prevent seizures in women with severe preeclampsia and to treat seizures in women with eclampsia. IV magnesium has been shown to be superior to other anti-epileptic agents in eclampsia.

What happens to patients with pre-eclampsia?

Most women with preclampsia become normotensive within 2 weeks of delivery.

The kidney is the organ most likely to be affected by endothelial injury in preeclampsia. Kidney injury is rare but can be seen in severe disease. Oliguria (urine output < 500 cc/day) indicates a much more severe clinical picture. Sudden onset or worsening of edema is a cause of concern in preeclamptic patients. Thrombocytopenia and liver damage are other clinical manifestations.

Central nervous system (CNS) effects include headache and blurred vision with hyperreflexia. Seizures indicate a progression to eclampsia and require immediate delivery of the fetus.

Patients with severe preeclampsia or eclampsia should be hospitalized immediately, considered for prompt delivery, given intravenous magnesium sulfate for seizure treatment or prophylaxis, and treated with antihypertensive medications to control blood pressure.

Patients with preeclampsia are at higher risk for future cardiovascular and cerebrovascular disease, as well as end-stage renal disease, although the absolute risk is low.

Are there clinical practice guidelines to inform decision making?

• ACOG Hypertension in Pregnancy Guidelines

Other considerations

Secreted placental anti-angiogenic factors are involved in the pathogenesis of preeclampsia. Soluble fms–like tyrosine kinase-1 (sFlt1) is a soluble vascular endothelial growth factor (VEGF) receptor that binds to pro-angiogenic factors such as VEGF and placental growth factor (PIGF), inhibiting their actions. Excess production of sFlt1 from the placenta results in endothelial dysfunction in preeclampsia. Circulating levels of sFlt1 have been used in studies as a biomarker to predict preeclampsia.

Meta-analysis that included more than 32,000 women suggested a small but significant reduction of the relative risk for pre-eclampsia with the use of aspirin (RR 0.81-0.90)

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