This photo makes it pretty clear.  The baby on the left has been starved of blood and iron.  Long term consequences include lower IQ and imprinted suffocation trauma.

http://members.tranquility.net/~rwinkel/janel/LemayCordClamp.html

Anemia resulting from premature clamping may lead to long-term
cognitive deficiencies, even where iron supplements are given:
http://archpedi.ama-assn.org/cgi/content/abstract/160/11/1108

SIDS has been correlated with abnormalities in neurochemical
metabolism in the brainstem, which is the area most affected by
ICC.   http://members.tranquility.net/~rwinkel/MGM/blog/sids.txt

The finding that boys are more vulnerable to the effects of ICC
than girls correlates with higher rates of both SIDS and autism
among boys.
http://members.tranquility.net/~rwinkel/MGM/blog/umbilical_gender.txt