Putting a newborn in skin to skin contact within 5 minutes after birth and leaving them there for at least an hour helps relieve stress on the baby's body and regulate its heart rate, according to a recent study. 

Researchers looked at the heart rates and oxygen levels of newborns who were placed skin to skin with their mothers within 5 minutes and after 5 minutes of birth, and found the early group reached a stable heart rate much earlier than the later group.  In a related study, doctors compared the level of the stress-hormone cortisol (high levels also weaken the immune system) in the baby's saliva at 1 minute, 1 hour, and 2 hours after birth.  The researchers discovered that, while all of the babies started with a nearly identical level at 1 minute, those who were in skin to skin contact with their mothers for longer than an hour produced significantly less stress chemical at the 1 and 2 hour marks than those who were separated prior to the 60 minute mark.  The findings of the study suggest that prolonged skin to skin contact may have a lasting benefit on reducing the stress hormone in babies beyond the hour mark, as well.

Is this a big surprise?  Smart birthing centers are realizing the flight to home births have more to do with a desire to reconnect with the power of the natural birth experience, and have changed their baby-factory policies to emphasize the maternal-infant connection over mechanical monitoring.  Studies like this are important because they show that skin to skin contact has real physiological, neurological, and immune system benefits, and is more than just a "new-age" preference.

Yuki Takahashi, Koji Tamakoshi, Miyoko Matsushima, Tsutomu Kawab (2011). "Comparison of salivary cortisol, heart rate, and oxygen saturation between early skin-to-skin contact with different initiation and duration times in healthy, full-term infants." Early Human Development 87(3):151-157. doi:10.1016/j.earlhumdev.2010.11.012