When routine becomes extraordinary: diagnosing and managing early preeclampsia.(The Master Class)

Classic preeclampsia occurs at the end of pregnancy, its hallmark a triad of symptoms listed in every textbook: hypertension, swelling, and elevated protein in the urine. We deliver these women, their blood pressures revert to normal, and we move on. Unless these patients have underlying renal disease, their hypertension is unlikely to recur.

But atypical preeclampsia often finds practitioners scratching their heads.

A woman with mild hypertension shows up at a routine prenatal visit in her mid-second trimester--a time when the blood pressure typically goes down. Maybe there's some protein in her urine, but we may feel tempted to shrug off these subtle blips on the radar screen as trivial variations from the norm. And that can be a very serious mistake.

When a woman in her second trimester has an elevation in blood pressure, repeat the reading as many times as necessary to obtain a true picture. Then, figure out why it is high. The mildly elevated reading recorded by the nurse may be the first sign of early preeclampsia, which probably represents a different and more serious disease than does preeclampsia at term.

Some degree of hypertension affects 5%-8% of all pregnancies, making it a significant complication. A small but important percentage of these cases involves mid-second trimester preeclampsia, which has a much higher chance of recurrence (perhaps 40%-50%) than does preeclampsia at the end of pregnancy.

Keeping in mind that medical conditions frequently drive early preeclampsia, consider relevant disorders such as diabetes, chronic hypertension, autoimmune diseases, and thrombophilia. Often, these conditions will have been monitored throughout the pregnancy, but sometimes they may be revealed only by the presence of preeclampsia. General practitioners may have overlooked these conditions or their significance before referring the patient to us.

In one such recent case, we saw a 28-year-old woman with hypertension and 8 g of protein in her urine at 25 weeks' gestation. She had a history of lupus and antiphospholipid syndrome, with previous deep vein thromboses and pulmonary emboli before this pregnancy. She had two previous miscarriages and should have been on low-dose aspirin and heparin before conception, but her local practitioners had overlooked her highly elevated risk for adverse vascular events. No renal studies had been done during her pregnancy, and no maternal-fetal medicine specialist had been consulted.