induction and augmentation of labour

Abnormalities of the Powers (uterine contractions)
Uterine dystocia denotes any abnormality in the force or coordination of uterine contractility that prevents the normal progress of labor.

3 categories:
1- hypotonic dysfunction (mostly seen in primigravida) & overdistended uterus.
2- hypertonic dysfunction,
3- uncoordinated dysfunction.

normal uterine activity during labor
1-relative intensity of contractions is greater in the fundus than in the midportion or lower uterine segment (this is termed fundal dominance)
2- the average value of the intensity of contractions is more than 24 mm Hg
3- in the active phase of labor, pressures increase to 40–60 mm Hg)
4- the basal resting pressure of the uterus is between 12 and 15 mm Hg
5- contractions are well synchronized in different parts of the uterus
6- the frequency of contractions one every 2–3 minutes during the active phase
7- the duration of effective contraction in active labor reaches 60 seconds
8- the rhythm and force of contractions are regular.

Hypotonic dysfunction

Hypotonic dysfunction responds well to oxytocin but care must be taken to rule out cephalopelvic disproportion and malpresentation.
Active management of labor has been shown to decrease perinatal morbidity and cesarean section rates.