These findings support the theory that infections during this period can trigger brain damage and the development of cerebral palsy.
The study took place at the Adelaide Women's and Children's Hospital in Australia and involved 443 children with cerebral palsy and 883 control babies. All babies were born to white mothers between 1986 and 1999.
Blood samples taken within a few days of birth were used to test for the presence of neurotropic viruses (a group of viruses including herpes viruses, which can all cross the placenta and infect the fetus).
Exposure to viral infection was common in all newborn babies, especially in preterm babies, implying that infection before birth may also be linked to preterm delivery.
Herpes group B viruses were found more often in babies who were later diagnosed with cerebral palsy than in control babies. In fact, the risk of cerebral palsy was nearly doubled with exposure to herpes group B viruses.
Despite some limitations, this study shows that perinatal exposure to neurotropic viruses is associated with preterm delivery and cerebral palsy, say the authors. Future studies are planned to investigate the possible causes of this link, they conclude.