Ultimately, the task force proposed that we utilize the two categories of “superimposed preeclampsia” and “superimposed preeclampsia with severe features,” and in doing so, it noted that there “often is ambiguity in the diagnosis of superimposed preeclampsia and that the clinical spectrum of disease is broad.” Indeed, the diagnosis of superimposed preeclampsia as presented in the report remains vague and open to interpretation. In my institution, it has created significant confusion.
The report states that superimposed preeclampsia is likely when any of the following are present: 1) a sudden increase in blood pressure that was previously well controlled or escalation of antihypertensive medications to control blood pressure, or 2) new onset of proteinuria or a sudden increase in proteinuria in a woman with known proteinuria before or early in pregnancy.
It is not clear, however, what is considered a sudden increase in blood pressure, and it is concerning that any escalation of medication could potentially prompt this diagnosis. Is an increase in systolic blood pressure from 140 mm Hg to 150 mm Hg or an increase in diastolic blood pressure from 90 mm Hg to 100 mm Hg between two prenatal visits considered a “sudden increase”? Does an increase in methyldopa dosage from 250 mg daily to 500 mg daily to keep blood pressure within the range of mild hypertension mean that the patient should be diagnosed with superimposed preeclampsia? Hypertension is likely to increase and require an escalation of antihypertensive medications as patients with chronic hypertension progress through their pregnancies.
Similarly, a “sudden increase in proteinuria” – or “sudden, substantial, and sustained increases in protein excretion,” as written elsewhere in the report with respect to superimposed preeclampsia – also is undefined. What exactly does this mean? That we lack clinically meaningful parameters and clear descriptions of acceptable criteria/scenarios for observation rather than intervention is troubling, particularly because some of these women may have preexisting renal disease with expected increases and fluctuations in protein excretion during advanced gestation.
We must be cautious about making a diagnosis of superimposed preeclampsia based on changes in blood pressure or urinary protein alone, lest we have unnecessary hospitalizations and interventions. I recommend that the diagnosis of superimposed preeclampsia be made based on either the new onset of proteinuria in association with mild hypertension after 20 weeks or on elevation in blood pressure to severe ranges (systolic BP greater than or equal to160 mm Hg and/or diastolic BP greater than or equal to 110 mm Hg) despite the use of maximum doses of one antihypertensive drug.
Regarding superimposed preeclampsia with severe features, I recommend that in the case of blood pressure elevation, it be diagnosed only after maximal doses of two medications have been used. Specifically, I recommend that superimposed preeclampsia with severe features be defined as either CHTN or superimposed preeclampsia in association with either systolic BP greater than or equal to 160 mm Hg and/or diastolic BP greater than or equal to 110 mm Hg on at least two occasions despite use of maximum doses of labetalol (2,400 mg/day) plus long-acting nifedipine (120 mg/day), or with any of the other severe features.
In a second installment of the Master Class, I will elaborate on the treatment of severe GHTN and address the management of preeclampsia with severe features as well as postpartum management of hypertension during pregnancy.