In-clinic readings miss 56% of hypertension cases in severely preeclamptic women

Hypertension during pregnancy is far from a rarity, but in women with severe preeclampsia, the diagnosis could be both cloaked and fatal, new research published in Hypertension suggests.

Preeclampsia affects around 3.4 percent of all pregnancies in the U.S., and between 2 and 8 percent of pregnancies across the globe, according to the U.S. Department of Health and Human Services. But while the disease is thought to account for up to 15 percent of maternal deaths worldwide, its symptoms are often overlooked.

“The problem is high blood pressure after pregnancy often goes unnoticed because many of these women have normal blood pressure readings in the doctor’s office,” study author Laura Benschop, MD, said in a release from the American Heart Association. “We aimed to determine how common it is for women who have preeclampsia to have high blood pressure in the year after pregnancy, by looking at more than just their blood pressure readings in the doctor’s office.”

Benschop and her colleagues at Erasmus Medical Center in Rotterdam, Netherlands, studied 200 women who were diagnosed with severe preeclampsia during their pregnancies. For the purposes of the study, preeclampsia was defined as a systolic blood pressure of 160 mmHg or higher, or a diastolic blood pressure of 110 mmHg or higher.

Since the researchers’ hypothesis stemmed from the idea that women are inadequately monitored for hypertensive symptoms post-delivery, they followed subjects for a year, taking blood pressure readings both in the clinic and throughout the day.

More than 41 percent of women with severe preeclampsia showed signs of high blood pressure in the year following their pregnancies, the authors reported. The most common type of hypertension, which was present in 17.5 percent of the study population, was masked hypertension—a condition in which blood pressure readings are normal in a doctor’s office but abnormal outside of it. Nearly 15 percent of women were diagnosed with sustained hypertension, and 9.5 percent were diagnosed with white coat hypertension, which occurs when blood pressure readings are higher in the doctor’s office than they are in everyday life.

“Our findings suggest women who have high blood pressure during pregnancy should continue to monitor their blood pressure long after they’ve delivered their babies,” Benschop said. “It’s not only important to monitor blood pressure in the doctor’s office, but also at different times of the day and night, at home.”

If only in-clinic readings were used to diagnose hypertension, the authors wrote, clinicians would have missed 56 percent of high blood pressure cases in the study pool.

“We’ve shown here that high blood pressure comes in many forms after pregnancy,” Benschop said. “Women who know their numbers can take the proper steps to lower their blood pressure and avoid the health consequences of high blood pressure later in life.”