For a more birds-eye view of the issue, check out the following:

Birth as we know it (video)
http://www.birthasweknowit.com/

Orgasmic birth (video)
http://www.orgasmicbirth.com/

More resources
http://consciouswoman.org/category/resources/childbirth/

The main lesson to take away from the above is that natural birth
is much more than a way to get the baby from point A to point B.
It also has a crucial psychological function which has
been entirely ignored (in fact pathologized) by medicine for centuries.
It is an intricate biological/hormonal recipe for establishing an
immediate, over-the-top, transcendent, animalistic bond between
mother and baby, the primary mechanism by which the baby is empowered
and protected from day one, so that the mother is less likely to
hand off her son to authority figures wielding knives, for instance.
From the baby's point of view, the experience sets the basic
psychological template around which its future experiences are
interpreted.  Adverse events in this crucial period (which may not
be perceived as adverse by uninformed observers, but which can
nonetheless be traumatic for the baby, such as disruption of the
maternal hormonal environment and premature cord clamping) can
actually set the stage for repetitive intergenerational dysfunction,
a phenomenon which may eventually be understood to mean the difference
between a civilized culture and a barbaric one.

Also, seemingly commonsensical medical interventions can have a major
impact on the future health of the baby.  For instance, immediate
skin to skin contact with the mother would colonize the baby's skin
with the organisms for which the mother's breastmilk confers immunity,
yet the standard procedure is to immediately wrap the baby tightly
in a blanket.  Not only does this expose the baby to hospital germs,
it also amounts to tactile sensory deprivation, which is adverse
to the baby's neurological development (http://www.violence.de/)

Checking the mouth for obstructions by inserting the finger may
colonize the mouth with hospital staph germs, some of which are
responsible for tooth decay. 

Generally speaking, we can learn a lot about normal mammalian birth
and how to cooperate with it by observing birth in other mammals.
Obstetricians could probably learn a lot from veterinarians.

The following gives a glipse of the entirely unscientific and reckless
practices that have been routinely imprinted on newborns by western
obstetrics:

The vagus nerve network and the imprint of circumcision on it:
http://www.sciam.com/article.cfm?id=kindness-emotions-psychology&page=2
http://www.cirp.org/library/pain/porter2/                                       

Twilight sleep in obstetrics
http://www.medicinenet.com/script/main/art.asp?articlekey=10226
(It's a remarkable fact that most americans alive today were
birth-imprinted with this concoction of morphine and scopalomine
(a delirium-producing hallucinogen) and research now shows that
chemical/drug imprinting has a major impact on future addictions
and even suicide methods (see birthUSA3.txt).  Apparently the main
purpose of this amnesia-producing mixture was to keep the mother
from remembering the trauma of medieval western obstetrical practices)

Business of being born (video)
http://www.thebusinessofbeingborn.com/

The other side of the glass (video)
http://theothersideoftheglassthefilm.blogspot.com/
This film (under construction) will show how the traditional role for
the father's role in birth, protecting the space around the birthing
mother (which is arguably part of nature's birthing blueprint) has
been discarded in favor of the medical model.  Protective fathers
may end up being the only way to force needless and harmful medical
interventions out of the birthing experience.  This film is an attempt
to empower fathers with the knowledge they need to protect their loved
ones.