October is Pregnancy and Infant Loss Awareness month. One in four women in the United States will experience the loss of a pregnancy or an infant. Of the estimated 4 million pregnancies each year, that means that 900,000 to 1 million will end in miscarriage. Researchers continue to look at all avenues to determine causes behind miscarriages, and a recent study conducted by the American Heart Association has made a link between higher blood pressure in women prior to conception and increased miscarriage risk. This is even if the women are not diagnosed with hypertension. The results of the study were published in the American Heart Association’s journal, Hypertension.

It should be noted that the study was conducted on over 1,200 women who had already experienced at least one miscarriage, so while the researchers are not ready to generalize the results across the population, the study definitely showed a strong link between blood pressure and pregnancy.

"Elevated blood pressure among young adults is associated with a higher risk of heart disease later in life, and this study suggests it may also have an effect on reproductive health," said Carrie J. Nobles, Ph.D, lead author of the study and a postdoctoral fellow in the Epidemiology Branch of the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD) in Bethesda, Maryland.

This is the first study of its type to look at blood pressure prior to conception and how it impacts pregnancy results. The researchers wanted to determine if taking low-dose aspirin might reduce the miscarriage risk. The aspirin did not seem to have any impact across the participants, but they did find a correlation between miscarriage and blood pressure rates. They noted an 18 percent increased risk of pregnancy loss for every 10-point increase in diastolic blood pressure (the lower number) and a 17 percent increased risk of miscarriage for every 10-point increase in mean arterial pressure. These numbers were consistent for preconception and early-pregnancy blood pressure.

"The impact of cardiovascular risk factors starts really early in life. Physicians treating women of reproductive age should pay attention to slightly elevated blood pressure because it may have other not-well-recognized effects, such as adverse pregnancy outcome," said Enrique F. Schisterman, Ph.D., senior author of the study and Senior Investigator and Chief of the Epidemiology Branch of NICHD.

More studies across a more diverse group of women are necessary before the researchers can apply broad results (this study included mostly white females who had experienced at least one miscarriage). However, it does indicate that leading a heart healthy life may also improve reproductive health.

Visit the American Heart Association for more information on tips for reducing risks of heart disease at www.heart.org.