Preeclampsia with or without severe features
We need to clarify and simplify how we think about GHTN and preeclampsia with or without severe features.
Most cases of preeclampsia will involve new-onset proteinuria, with proteinuria being defined as greater than or equal to 300 mg/day or a protein-creatinine ratio of greater than or equal to 0.3 mg/dL. In cases in which a dipstick test must be used, proteinuria is suggested by a urine protein reading of 1+. (It is important to note that dipstick readings should be taken on two separate occasions.) According to the report, preeclampsia also may be established by the presence of GHTN in association with any one of a list of features that are generally referred to as “severe features.”
Various boxes and textual descriptions in the report offer a sometimes confusing picture, however, of the terms preeclampsia and preeclampsia with severe features and their differences. For clarification, I recommend that we define preeclampsia with severe features as GHTN (mild or severe) in association with any one of the severe features.
Severe features of preeclampsia
- Platelet count less than 100,000/microliter.
- Elevated hepatic transaminases greater than two times the upper limit of normal for specific laboratory adult reference ranges.
- Severe persistent right upper quadrant abdominal pain or epigastric pain unresponsive to analgesics and unexplained by other etiology.
- Serum creatinine greater than 1.1 mg/dL.
- Pulmonary edema.
- Persistent cerebral disturbances such as severe persistent new-onset headaches unresponsive to nonnarcotic analgesics, altered mental status or other neurologic deficits.
- Visual disturbances such as blurred vision, scotomata, photophobia, or loss of vision.
I also suggest that we think of “mild” GHTN (systolic BP of 140-159 mm Hg or diastolic BP 90-109 mm Hg) and preeclampsia without severe features as one in the same, and that we manage them similarly. The presence or absence of proteinuria is currently the only difference diagnostically. The only difference with respect to management – aside from a weekly urine protein check in the case of GHTN – is the frequency of nonstress testing (NST) and amniotic fluid index (AFI) measurement (currently once a week for GHTN and twice a week for preeclampsia).
Given that unnecessary time and energy may be spent differentiating the two when management is essentially the same, I suggest that preeclampsia be diagnosed in any patient with GHTN with or without proteinuria. All patients can then be managed with blood pressure checks twice a week; symptoms and kick count daily; NST and AFI twice a week; estimated fetal weight by ultrasound every third week; lab tests (CBC, liver enzymes, and creatinine) once a week, and delivery at 37 weeks.
Superimposed preeclampsia with or without severe features
As the report states, the recognition of preeclampsia superimposed on chronic hypertension is “perhaps the greatest challenge” in the diagnosis and management of hypertensive disorders in pregnancy. Overdiagnosis “may be preferable,” the report says, given the high risk of adverse pregnancy outcomes with superimposed preeclampsia. On the other hand, it says, a “more stratified approach based on severity and predictors of adverse outcome may be useful” in avoiding unnecessary preterm births.