The Human Placenta defies evolution...

The Risky Expulsion of the Placenta after Birth
During the baby’s development, the placenta is securely attached to the endometrium of the uterus by some of the larger branches of each cotyledon. When the uterus contracts to expel the placenta after the birth of the baby, some of the endometrial surface is torn off with it. This results in severing about 20 large uterine arteries which, if unchecked, would involve the loss of blood at a rate of about one pint per minute. Since fewer than five quarts (4 liters) of blood are in the adult female body, all the blood would be lost in less than 10 minutes. It is also important to note that the blood-clotting mechanism is suppressed in the placenta and uterine blood vessels during pregnancy, creating a situation comparable to a hemophiliac with 20 severed arteries. These factors result in a wound that no one would expect to survive!

Saved by a Miracle!
How does a woman survive childbirth with such a wound? Here is another example of the awe-inspiring work of God, the Creator and Sustainer of life. You see, each of the severed uterine arteries has a precisely placed muscular sphincter that acts like a purse string, or a surgeon’s hemostat, to immediately close off the loss of blood. As a result, a normal birth involves the loss of only about a pint of blood. Simply amazing!
more here:
http://www.answersingenesis.org/arti...v2/n1/placenta