A new Australian study has found that exposure to certain viral infections shortly before and after birth, the perinatal period, is associated with cerebral palsy.
The findings support the theory that infections during this period can trigger brain damage and the development of cerebral palsy.
The study at the Adelaide Women's and Children's Hospital in Australia involved 443 children with cerebral palsy and 883 control babies.
All babies were born to white mothers between 1986 and 1999.
Within a few days of birth blood samples taken were used to test for the presence of a group of viruses including herpes viruses, known as neurotropic viruses, which can cross the placenta and infect the fetus.
Apparently 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.
The team found that Herpes group B viruses were found more often in babies who were later diagnosed with cerebral palsy than in control babies.
The risk of cerebral palsy was in fact almost double with exposure to herpes group B viruses.
The authors say that despite some limitations, the study shows that perinatal exposure to neurotropic viruses is associated with preterm delivery and cerebral palsy.
They are apparently planning further studies in order to investigate the possible causes of this link.
The study is published online by the British Medical Journal.