The phase active of labor, period that both mothers and doctors have called for a long time simply birth, understood since the cervix dilates ' one to two centimeters per hour faster and the presentation down the birth canal -, is characterized by uterine contractions that allows a rapid cervical dilatation in which uterine contractions increase gradually; whose values averages are: 41 mmHg., for the intensity and 4.2 contractions every 10 minutes for the frequency; average uterine activity is 187 UM and uterine tone average of 10 mmHg. Any delay in the cervical dilation during the extension of the second period should raise suspicions about possible hazards, such as: uterine dysfunction (literally difficult birth), which is characterized by an abnormally slow progression of labor and is a consequence of