Preconception blood pressure and pregnancy loss could be linked

By Julie Griffiths on 03 April 2018 Research

Women with elevated blood pressure before conception could be at an increased risk of pregnancy loss, according to a new study.

Researchers at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) found that for every 10mmHg increase in diastolic blood pressure there was an 18% higher risk for pregnancy loss among the study population.

The study also found a 17% increase in pregnancy loss for every 10mmHg increase in mean arterial pressure, a measure of the average pressure in the arteries during full heart beat cycles.

Data were analysed and collected as part of the ‘Effects of aspirin in gestation and reproduction’ (EAGeR) trial, which sought to determine if daily low-dose aspirin (81mg) could prevent miscarriage in women who had a history of pregnancy loss.

The EAGeR trial enrolled more than 1200 women aged 18 to 40 years and took blood pressure readings before the women were pregnant and again in the fourth week of pregnancy.

Average diastolic blood pressure for the women in the study was 72.5mmHg; normal blood pressure in adults is a diastolic reading of below 80mmHg. The study authors began to see an increase in pregnancy loss among women who had a diastolic reading above 80mmHg (approximately 25% of the participants).

The researchers note that while 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.

However, they added 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.

Senior study author and chief of the epidemiology branch at NICHD Enrique Schisterman said: ‘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.’

Co-author and postdoctoral fellow Carrie Nobles said that further research could help determine if treating elevated blood pressure and other health risks before conception improves pregnancy outcomes.

The study was published in Hypertension, read it here.