Diagnostic evaluation of a pregnant or postpartum woman with persistent systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg*

BP: blood pressure.

* Blood pressure should be elevated on at least two occasions at least four hours apart. However, if systolic pressure is ≥160 mmHg or diastolic pressure is ≥110 mmHg, confirmation after a short interval, even within a few minutes, is acceptable to facilitate timely initiation of antihypertensive therapy.

¶ The onset of preeclampsia and gestational hypertension is almost always after 20 weeks of gestation. Preeclampsia before 20 weeks of gestation may be associated with a complete or partial molar pregnancy or fetal hydrops. Postpartum preeclampsia usually presents within two days of delivery. The term "delayed postpartum preeclampsia" is used for signs and symptoms of the disease leading to readmission more than two days but less than six weeks after delivery.

Δ Significant proteinuria is defined as ≥0.3 g in a 24-hour urine specimen or protein/creatinine ratio ≥0.3 (mg/mg) (34 mg/mmol) in a random urine specimen or dipstick ≥1+ if a quantitative measurement is unavailable.

◊ Almost all women with the new onset of hypertension and proteinuria at this gestational age or postpartum have preeclampsia, but a rare patient may have occult renal disease exacerbated by the physiologic changes of pregnancy. An active urine sediment (red and white cells and/or cellular casts) is consistent with a proliferative glomerular disorder but not a feature of preeclampsia. Women with chronic hypertension who had proteinuria prior to or in early pregnancy may develop superimposed preeclampsia. This can be difficult to diagnose definitively, but should be suspected when blood pressure increases significantly (especially acutely) in the last half of pregnancy/postpartum or signs/symptoms associated with the severe end of the disease spectrum develop.

§ Photopsia (flashes of light), scotomata (dark areas or gaps in the visual field), blurred vision, or temporary blindness (rare); severe headache (ie, incapacitating, "the worst headache I've ever had") or headache that persists and progresses despite analgesic therapy; altered mental status. Seizure occurrence upgrades the diagnosis to eclampsia.

• Antiphospholipid syndrome
• Acute fatty liver of pregnancy
• Thrombotic thrombocytopenic purpura (TTP)
• Hemolytic uremic syndrome (HUS)

The laboratory findings in these disorders overlap with those in preeclampsia with severe features. (Refer to table in the UpToDate topic on the clinical manifestations and diagnosis of preeclampsia.) The prepregnancy history, magnitude and spectrum of laboratory abnormalities, and additional presence of signs and symptoms not typically associated with preeclampsia help in making the correct diagnosis, which is not always possible during pregnancy.

In addition, a variety of medical disorders may be associated with hypertension and one or more of the signs and symptoms that occur in women with preeclampsia with severe features. These patients can usually be distinguished from patients with preeclampsia by taking a detailed history, performing a thorough physical examination, and obtaining relevant laboratory studies.