Elevated Blood Pressure Before Pregnancy May Increase Chance of Pregnancy Loss

Pregnant woman having her blood pressure taken.

Photo: Asteroid/iStock

Elevated blood pressure before conception may increase the chances for pregnancy loss, according to an analysis by researchers at NIH. The authors conclude that lifestyle changes to keep blood pressure under control could potentially reduce the risk of loss. The study appears in Hypertension.

The analysis found that for every 10 mmHg increase in diastolic blood pressure (pressure when the heart is resting between beats), there was an 18 percent higher risk for pregnancy loss among the study population. Millimeter of mercury, or mmHg, is the unit of measure used for blood pressure. Researchers at NICHD conducted the study.

“Elevated blood pressure is linked to heart disease, stroke and kidney disease,” said the study’s senior author, Dr. Enrique Schisterman, chief of NICHD’s Epidemiology Branch. “Our findings suggest that attaining a healthy blood pressure before pregnancy could not only have benefits later in life, but also reduce the chances for pregnancy loss.”

The researchers note that the study does not prove that elevated blood pressure causes pregnancy loss. It is possible that another, yet-to-be identified factor could account for the findings. They added, however, that the relationship between preconception blood pressure and pregnancy loss remained the same when they statistically accounted for other factors that could increase pregnancy loss, such as increasing maternal age, higher body mass index or smoking.

“Our results suggest that further research could help determine if treating elevated blood pressure and other health risks before conception improves pregnancy outcomes,” said the study’s first author Dr. Carrie Nobles, a postdoctoral fellow in the Epidemiology Branch.