Dystocia refers to difficult or slow labor progress that may be caused by abnormalities of the passageway (mother's pelvis), passenger (baby), or powers (uterine contractions). There are two main types of uterine dysfunction that can cause dystocia: hypotonic dysfunction where contractions are insufficient and hypertonic dysfunction where contractions are incoordinated. Labor patterns are considered abnormal if the active phase of dilation progresses less than 1 cm/hr for nulliparous women or 1.5 cm/hr for multiparous women. Arrest disorders occur when dilation or descent stops progressing for over 2 hours. Precipitous labor is extremely rapid labor and delivery caused by abnormally low resistance in the birth canal

1. DYSTOCIA
Liezel B. Alfonso, MD

2. DYSTOCIA
 - difficult labor
 - slow labor progress

3. It may be associated with abnormalities
involving:
 - Abnormalities of the Passage
 - Abnormalities of the Passenger
 - Abnormalities of the Powers

4. ABNORMALITIES OF THE EXPULSIVE
FORCES
Types of Uterine Dysfunction:
1) HYPOTONIC UTERINE DYSFUNCTION
- more common
- no basal hypertonus
- uterine contractions have a normal
gradient pattern (synchronous)
- pressure during contraction is insufficient
to dilate the cervix

5.  2) HYPERTONIC UTERINE
DYSFUNCTION
= incoordinate uterine dysfunction
- either basal tone is elevated
- pressure gradient is distorted

6. ACTIVE PHASE DISORDERS
 PROTRACTION DISORDER
 - < 1cm/hr cervical dilatation for a
minimum of 4 hrs
 ARREST DISORDER
 - no dilatation for 2 hrs or more

7. Definitions of Abnormal Patterns of Labor
LABOR PATTERN NULLIPARA MULTIPARA
PROLONGATION DISORDER
Prolonged Latent Phase > 20 hrs > 14 hrs
PROTRACTION DISORDERS
Protracted Active Phase Dilatation
(Phase of maximum slope dilatation)
< 1.2cm/hr < 1.5cm/hr
Protracted Descent (maximum slope
of Descent during the pelvic division)
< 1 cm/hr < 2 cm/hr

8. ARREST DISORDERS:
1. Prolonged Deceleration Phase
(cervical dilatation arrested at
8 to 9 cm)
> 3 hrs > 1 hr
2. Secondary Arrest of Dilatation
(progressive cervical dilatation
stops at the phase of maximum
slope)
> 2 hrs
3. Arrest of Descent (
progressive cervical dilatation
stops at the phase of maximum
slope)
> 1 hr
4. Failure of Descent (station 0) Lack of expected descent during
deceleration phase or second
stage of labor
5. Prolonged second stage > 3 hrs with
regional
anesthesia
> 2hrs without
regional
anesthesia
> 2hrs with
regional
anesthesia
> 1hr without
regional
anesthesia

9. Criteria before the diagnosis of arrest during first-stage
labor is made:
 1) The latent phase has been completed,
and the cervix is dilated 4cm or more.
 2) A uterine contraction pattern of 200
Montevideo units or more in a 10-minute
period has been present for 2 hrs without
cervical change.

10. Second-stage disorders
 - disproportion of the fetus and pelvis
are frequent

11. PRECIPITOUS LABOR AND
DELIVERY
 - extremely rapid labor and delivery
 - result from an abnormally low
resistance of the soft parts of the birth
canal, from abnormally strong uterine
and abdominal contractions
 - Or rarely, from the absence of painful
sensations and thus a lack of
awareness of vigorous labor