A new understanding of the second stage of labor: implications for nursing care.

A reconceptualization of the second stage of labor is proposed, with an early phase of descent and a later phase of active pushing, as the basis for nursing care related to direction or support of expectant mother's bearing-down efforts. This reconceptualization challenges the rules that have accompanied second stage by providing criteria for the obstetric conditions optimal for fetal descent that develop during the initial phase of second stage as the fetal head rotates to an anterior position and descends to at least a 1+ station. The phase of active pushing is accompanied by a decline in fetal pH and should be shortened, not only by assisting the woman with effective bearing-down but also by allowing a longer early phase of second stage and encouraging the woman to push only when the obstetric conditions are optimal.