ABNORMAL PROGRESS OF LABOR

•	Definition.
•	Causes and effects. 
•	Assessment.
•	Management.

Definition

1.	Progress in latent phase:

a.	Multip: > 4 hours.

b.	Primip: > 6 hours.

2.	Primary dysfunctional labor: progress is slow in active phase.

3.	Secondary arrest: normal in early active phase, but slows down later on; common cause is malpresentation.

Causes and Effects

1.	Aetiology:

a.	Power:

i.	primary uterine dysfunction.

ii.	poor maternal effort.

iii.	incoordinate contractions.

iv.	excessive sedation.

b.	Passage:

i.	contracted pelvis.

ii.	CPD.

iii.	obstruction.

iv.	fibrosis.

v.	shape.

c.	Passenger:

i.	macrosomia.

ii.	head size.

iii.	maturity.

iv.	flexion.

v.	position of skull.

vi.	malpresentation.

2.	Causes of death and morbidity:

a.	Sepsis.

b.	Obstructed labor.

c.	Rupture of the uterus.

d.	Postpartum haemorrhage.

e.	Increase in Caesarean section rates for dystocia and difficult labor.

3.	Prolonged labor is associated with high levels of morbidity and mortality.

Assessment

1.	To decide on two courses of action:

a.	Allow labor to proceed.

b.	Perform LSCS.

2.	Assess power:

a.	Look at CTG: assess contractions in terms of frequency, intensity and duration.

b.	Optimal contractions are those that occur:

i.	once every 2 ½ minutes.

ii.	moderate to severe intensity.

iii.	last more than 30 seconds.

3.	Assess passenger:

a.	Abdominal examination:

i.	size of fetus.

ii.	descent: fifth above pelvic brim.

b.	Vaginal examination:

i.	caput / moulding: evidence of tight fit.

ii.	presentation and position.

4.	Assess passage: vaginal examination and clinical pelvimetry.

5.	Assess fetal condition: 

a.	Fetal distress on CTG.

b.	Meconium-stained liquor after VE.

6.	Assess maternal condition:

a.	General condition.

b.	Antenatal history.

c.	Risk factors: pre-eclampsia, CVS disease.

d.	Past history of difficult labor, etc.

Management

1.	If labor is allowed to continue, ensure:

a.	Adequate analgesia.

b.	Adequate hydration.

c.	Membranes are ruptured.

d.	Good uterine activity by augmentation with syntocinon. 

2.	Most common cause of an abnormal labor progress in primigravidae is primary uterine dysfunction.

3.	Women presenting in the active phase of labor (cervical dilatation more than or equal to 3cm) often progress and deliver normally.

4.	Monitoring with CTG:

a.	Abnormal progress of labor is recognized when the cervical dilatation on the partogram crosses the alert line (1cm/h).

b.	If the progress of the labor is within the action line (an arbitary line 2 to 4 hours to the right and parallel to the alert line), the labor may be allowed to progress.

c.	If, however, the progress of labor crosses the action line, then the labor should be augmented with oxytocin.

5.	Oxytocin is administered using a peristaltic infusion system with dose increments following set protocols.

6.	Continuous electronic fetal monitoring is recommended because of the risk of hyperstimulation and fetal death. 

7.	Generally, an eight hour period of augmentation of labor in the absence of gross disproportion will result in the majority of women delivering vaginally.

8.	However, if labor fails to progress despite adequate augmentation, then a LSCS is indicated.