My only knowledge is with horses and cows but with them if you express the colostrum off the milk comes in sooner (i.e. the day of birth instead of a few days later) which is fairly disastrous for young foals and calves but probably wouldn't be for a human since they get some immunities in the womb.

Do you have GD Sarah? I must have missed it. I think for women with GD when they KNOW there's a possibility of problems after birth then it's worthwhile.

For everyone else, the BFing relationship is as balanced and perfect as the birth process - if you intervene "in case" of problems you might very well end up getting those problems when you otherwise wouldn't have. Just my $0.02.