in vigorous newborns ( 1-minute apgar score greater than or equal to 7 ) , umbilical arterial and venous lactate levels were lowest with elective cesarean section done before the onset of labor , higher with cesarean section performed during labor , and highest at the time of vaginal delivery ( p less than 0.001 , tab . i ) .
C0473296
elective cesarean section
C0007876
cesarean section