In the last weeks of pregnancy, the baby typically moves into a vertex or head-down position, where he remains until birth. In the time of Hippocrates, the ancient Greek father of medicine, physicians believed that the fetus assumed this position so that he could kick off from the top of the uterus and push himself through the birth canal. Although the explanation is wrong, the fact is that the head-first delivery is best.
As labor continues and the baby descends into the birth canal, he turns his head. "The baby goes from typically looking sideways, toward one hip or the other, and rotates so that the back of the head is up and the baby is facing toward the mother's back," explains Dr. Copel.
As the mother pushes the baby out through the birth canal, the intrauterine pressure increases one last time. "Again, we don't know how the baby experiences that. I don't think Mother Nature intends to torture us. I don't think babies cry when they're born because they're in pain. I think it's a reflex that opens their lungs," says Dr. Copel. "Typically babies that are crying right after birth are just kind of making some noise — which has them breathing deeply and gets fluid out of their lungs."
They may also be adjusting to the sudden stimulation of light and sound after the relative soft lights and sweet music of the womb. "The difference between being in a 99.6 degree, fluid-filled, dark environment, and even a warm delivery room with lights and noise is so major that some of [the sleeping that they do right after birth] might just be reducing sensory stimulation until they get used to it," explains Dr. Copel. "If you shade most babies eyes immediately after birth, they'll open them and start looking around. They keep them scrunched up because it's like going from being in a really dark room to a really bright room for any of us. They've got a lot of adjusting to do."