What will cause term baby brain damage?

Several things: The most common would be lack of oxygen, head injury, infection or stroke or bleed (these lst two are rare unless there is a congenital problem).

Many R unexplained: Results from > 50, 000 pregnancies reported in the late 70's (nelson et al.)showed > 50% of cerebral palsy cases had normal pregnancy, labor& delivery. Infants are born with true knots in the cord & many have loops of cord tight about the neck. Some have hx of maternal infection, drug exposures etc. Contrary to the lunch tv adds, most are not caused by drs.