Feb. 25 (HealthDay News) -- Exposure to viral infection -- especially herpes viruses -- may be associated with high blood pressure during pregnancy and preterm birth, Australian researchers report.

The findings -- the first of their kind -- are a major advance in learning more about the cause of hypertension in pregnancy, according to the authors of the study, which was published in the British Journal of Obstetrics & Gynaecology.

Over 10 years, researchers from Adelaide's Women & Children's Hospital and the University of Adelaide detected the presence of viral nucleic acid in heel-prick blood samples from 1,326 newborns -- more than 400 of whom were diagnosed with cerebral palsy.

"This is an exciting finding and further studies are now required to look at the link between viral exposure in pregnancy and genetic susceptibility to adverse pregnancy outcomes, such as high blood pressure, premature delivery and cerebral palsy," research group leader Alastair MacLennan, a professor in the Department of Obstetrics and Gynaecology, said in a prepared statement.

High blood pressure occurs in up to 10 percent of first pregnancies in the United States and other developed nations. It's a common cause of death among pregnant women in developing countries.

Previously, the Adelaide group identified a link between viral infection in pregnancy, genetic mutations in genes controlling inflammatory and blood clotting processes, and the development of cerebral palsy. They also found an association between several hereditary gene mutations and changes in inflammatory proteins that may cause dysfunction and constriction of blood vessels in the placenta and brain, resulting in increased blood pressure during pregnancy.

"We are just beginning to understand the interaction and importance of exposure to viruses and genetic susceptibility to infection both in pregnancy and the newborn," Paul Goldwater, an associate professor and the research team's virologist, said in a prepared statement.

SOURCE: University of Adelaide, news release, Feb. 18, 2008