In contrast to patients with mild PIH, the clinical presentation of those with severe PIH or preeclampsia (and the potential for impending eclampsia) may include the following symptoms and signs:
- Generalized edema, including that of the face and hands
- Rapid weight gain
- Blurred vision or scotomata (ie, areas of diminished vision in the visual field)
- Severe, throbbing or pounding headaches
- Epigastric or right upper quadrant pain
- Oliguria (urinary output < 500 mL/d)
- Nausea, with or without vomiting
- Hyperactive reflexes
- Chest pain or tightness
- Shortness of breath.2,6,14
Medical History
Important questions to address in the patient’s medical history relate to risk factors for PIH, such as a history of renal disease, cardiac disease, or diabetes, previous history of PIH and/or preeclampsia, and abuse of cocaine or amphetamines—in addition to the specific aforementioned symptoms and signs of severe preeclampsia.5,6
Physical Examination
The clinician performing the physical exam should be attentive to accurate blood pressure measurements and any signs that suggest preeclampsia. Weight should be measured and BMI calculated at each prenatal visit.
If the patient’s blood pressure is markedly elevated, the focused physical examination should include an ophthalmologic examination for jaundice and for evidence of hypertensive retinopathy or papilledema; pulmonary and cardiac examination; abdominal examination, including palpation of the liver; examination of the face and extremities for edema; and a complete neurologic examination, including assessment of deep tendon reflexes and examination for clonus.
Laboratory Testing
In patients with PIH, laboratory evaluation should be focused to rule out preeclampsia. The potential for proteinuria (defined as ≥ 0.3 g/d in a 24-hour urine sample1,14) must be investigated at diagnosis and at regular visits during the pregnancy.1 At least two random urine samples, collected at least 6 hours apart, should be evaluated for protein. A spot (random) urine sample with a result of 2+ protein or greater is highly suggestive of proteinuria; a 24-hour urine collection is the gold standard by which such findings should be confirmed and protein levels in the urine quantified.1,14
Elevated blood pressure and proteinuria are the hallmarks of preeclampsia.6 Patients affected by these developments must be evaluated for signs and symptoms of severe preeclampsia. However, those with only mild elevations in blood pressure and little or no proteinuria may complain of sudden-onset throbbing or pounding headache, blurry vision, and severe epigastric pain—possibly indicating severe preeclampsia.5,10
In addition to laboratory evaluation for urinary protein excretion, the following tests are recommended by the American College of Obstetricians and Gynecologists (ACOG)14 to assess for end organ involvement, which is consistent with severe preeclampsia:
- Hematocrit, which may be either high, to suggest hemoconcentration; or low, indicating hemolysis
- Platelet count, which is normal in women with PIH and low in those with severe preeclampsia; if results are abnormal, this test should be followed by coagulation testing (international normalized ratio, activated partial thromboplastin time, fibrinogen)
- Renal function testing (blood urea nitrogen and creatinine may be elevated in severe preeclampsia), and random urine testing for proteinuria, as explained earlier
- Liver enzymes (which are elevated in severe preeclampsia), and
- Lactate dehydrogenase (which is elevated in severe preeclampsia).1,14
Additionally, researchers conducting a small cohort study (n = 163) reported in 2009 that in women with PIH, serum uric acid levels exceeding 309 µmol/L were predictive of preeclampsia, with 87.7% sensitivity and 93.3% specificity.19 An increase from first-trimester serum uric acid levels was also a strong prognostic factor for preeclampsia. Earlier this year, a Canadian investigative team reported an increased risk for premature birth (odds ratio, 3.2) and small infant size for gestational age (odds ratio, 2.5) in women with PIH and hyperuricemia.20 While the predictive value of uric acid has been debated to some extent,14 measurement is often included in the workup of patients with hypertensive pregnancies.5,6
The frequency of prenatal visits, laboratory testing, and fetal monitoring should be adjusted according to the severity of PIH. In mildly hypertensive patients, the general recommendation is urine and blood testing at weekly prenatal visits.14 Fetal well-being must be monitored regularly, although neither the type nor frequency of such testing has been well established. Generally, patients should be advised to count daily fetal movements, and they should be scheduled for either a nonstress test (NST) or a biophysical profile as soon as a diagnosis of PIH is made.1,2,6,14
According to a 2010 guidance from the United Kingdom’s National Institute for Health and Clinical Excellence (NICE),13,21 pregnant women with mild to moderate hypertension should undergo an initial ultrasonographic assessment of fetal growth and amniotic fluid volume at the time of diagnosis, then serially every 3 to 4 weeks. If results from initial fetal testing are normal, patients with mild PIH do not require repeat testing after 34 weeks’ gestation, unless conditions change (eg, preeclampsia, worsening hypertension, and/or change in fetal movements).1,2,14 The NICE guidelines also recommend umbilical artery Doppler velocimetry.13,21