Frédérick Leboyer M.D. was an obstetrician who was a predecessor in exploring advantages with uninterventional child birth. He's description of birth fits well with my experiences and the results from our research. Read what he had to say about the transition from being dependent of the placenta to start breathing by it's own:
Birth Without Violence (first published in 1974)
By Frederick Leboyer M.D

This is a citation from the Facebook page: Leaving A Baby's Umbilical Cord To Stop Pulsating (Delayed Cord Clamping)
"She [ Mother nature] has arranged it so that during the dangerous passage of birth, the child is receiving oxygen from two sources rather than one: from the lungs and from the umbilicus. Two systems functioning simultaneously, one relieving the other: the old one, the umbilicus, continues to supply oxygen to the baby until the new one, the lungs, has fully taken its place. However, once the infant has been born and delivered from the mother, it remains bound to her by this umbilicus, which continues to beat for several long minutes: four . . . five .. . sometimes more. Oxygenated by the umbilicus, sheltered from anoxia, the baby can settle into breathing without danger and without shock. At leisure. .. . In addition, the blood has plenty of time to abandon its old route (which leads to the placenta) and progressively to fill the pulmonary circulatory system. During this time, in parallel fashion, an orifice closes in the heart, which seals off the old route forever. In short, for an average of four or five minutes, the newborn infant straddles two worlds. Drawing oxygen from two sources, it switches gradually from the one to the other, without a brutal transition. One scarcely hears a cry. What is required for this miracle to take place? Only a little patience. " (Page 47 )