Family Matters

A Test to Predict High Blood Pressure in Pregnancy Is on the Horizon

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Preeclampsia is one of those terms you probably wouldn’t hear until your pregnancy test turns up positive. Then, regular prenatal urine and blood pressure screenings alert you to the condition, if they detect something awry.

It’s no joke: preeclampsia — or pregnancy-induced hypertension — affects up to 5% of pregnant U.S. women; in developing nations, that figure may be doubled. A leading cause of maternal death — preeclampsia kills up to 200,000 women each year, according to the World Health Organization — it has no cure other than delivery, which can present a major medical problem if the condition results in an extremely premature birth.

There’s really no way to know who will get preeclampsia, although women diagnosed in the past have a greater risk in subsequent pregnancies. But now for the first time, a group of scientists and doctors are announcing they’ve sussed out a way to predict in early pregnancy which women are likely to develop the disease in later pregnancy, when symptoms typically arise. Within five years, they hope to translate their findings into a cheap blood test that would be widely available to pregnant women everywhere.

“Everything we know about this condition suggests women do not become sick and present with preeclampsia until late in pregnancy, but the condition originates in early pregnancy,” said Louise Kenny, the study’s lead author and professor of obstetrics and gynecology at University College Cork in Ireland. “To develop effective treatment and prevention strategies — our ultimate goal — we need to be able to start treatment in early pregnancy. We need to be able to tell who is at risk and who is not.”

The study, released Monday in Hypertension: Journal of the American Heart Association, followed women who were already participating in an international trial of 7,000 women who were pregnant for the first time, with the goal to predict and prevent the major diseases that manifest themselves later in pregnancy. (In addition to preeclampsia, the specter of premature birth and fetal growth restriction loom large as pregnancy progresses. About one in six first-time mothers’ pregnancies will be complicated by at least one of these conditions.)

The study’s authors focused on 199 women in New Zealand and Australia. Using a screening panel of 14 metabolic markers, researchers predicted that 60 healthy, first-time pregnant New Zealand women in their 15th week of pregnancy would develop preeclampsia. The researchers then confirmed their findings with a more ethnically diverse group of Australian women. Like any screening test, there are some false starts. Think of it like this: for every 10 pregnant women who eventually develop preeclampsia, one will be misclassified as “normal.” Likewise, for every 10 pregnant women who have normal pregnancies, three will be falsely diagnosed as being on track to develop preeclampsia.

“At 15 weeks’ gestation, these results are remarkable,” says David Broadhurst, a co-author of the study and research scientist at Cork University Maternity Hospital in Ireland.

As science progresses, the test results could spark therapeutic interventions that could slash the likelihood of serious complications later in pregnancy. In other words, the test could eventually save lives.

Although the test is nowhere near ready to go, it might be worth asking your doc about the study if you know you’re at high risk for preeclampsia. Here are some well-known risk factors, according to the Mayo Clinic:

History of preeclampsia. A personal or family history of preeclampsia increases your risk of developing the condition.

First pregnancy. The risk of developing preeclampsia is highest during your first pregnancy or your first pregnancy with a new partner.

Age. The risk of preeclampsia is higher for pregnant women younger than 20 and older than 40.

Obesity. The risk of preeclampsia is higher if you’re obese.

Multiple pregnancy. Preeclampsia is more common in women who are carrying twins, triplets or other multiples.

Prolonged interval between pregnancies. This seems to increase the risk of preeclampsia.

Gestational diabetes. Women who develop gestational diabetes have a higher risk of developing preeclampsia as the pregnancy progresses.

History of certain conditions. Having certain conditions before you become pregnant — such as chronic high blood pressure, migraine headaches, diabetes, kidney disease, rheumatoid arthritis or lupus — increases the risk of preeclampsia.

Until that test becomes available, it couldn’t hurt to cozy up to Lady Godiva. According to a study in the Journal of Epidemiology, because chocolate has been linked to cardiovascular health, and preeclampsia has cardiovascular manifestations, it just might be helpful to treat yourself to some chocolate. Tenuous? Perhaps. But who cares? It’s just another excuse to indulge.