To Dr. David Hague, human pregnancy is Mar 15 2006
To Dr. David Hague, human pregnancy is a struggle between the fetus and mother. Evolutionarily speaking, the fetus "wants" as many resources as possible for itself while the mother "wants" to do what she can to spread her resources across as many children as possible. In theory, this is a cause of the many serious health problems surrounding pregnancy.
Update: Carl Zimmer has more about this on his blog.