A small study showed that 26% of the 65 infants in the study who had a vaginal birth had small intracranial hemorrhages in the brain as seen by unsedated MRIs of the newborns. While this was higher than they expected, they believe that it is a normally physiologic part of being born.
The study authors stressed that this should not change a woman's plans for delivery. Cesarean birth is not indicated to reduce the incidence.
Source:
"Intracranial Hemorrhage in Asymptomatic Neonates: Prevalence on MR Images and Relationship to Obstetric and Neonatal Risk Factors" Christopher B. Looney, BS, J. Keith Smith, MD, PhD, Lisa H. Merck, MD, MPH, Honor M. Wolfe, MD, Nancy C. Chescheir, MD, Robert M. Hamer, PhD and John H. Gilmore, MD. Radiology 2007;242:535-541.

