Research summaries for normal birth.

In this column, the author summarizes four research studies that contribute to the body of literature on the benefits and physiology of normal childbirth. The topics of the studies include the effect of digital rotation of the baby in occipito-posterior position on position at birth and birth outcomes; temperature disturbances during skin-to-skin contact among babies exposed to epidural analgesia and exogenous oxytocin during labor; the prevalence of and motivations for "maternal request" cesarean surgery; and the benefits of delayed clamping of the umbilical cord after birth.