Slow progress of labour has three fundamental causes:

These are often interrelated. Poor contractions are the most common cause of slow progress of labour.

Exclude malpresentations and poor contractions before making a diagnosis of disproportion.

Uterine contractions

“Good contractions” are characterized by:

Poor contractions lack the above characteristics. They may occur at any stage of labour. If you have excluded malpresentation and labour fails to progress in spite of good contractions, assume the cause to be disproportion. Poor contractions in the latent phase may represent false labour; do not confuse them with abnormal labour.

Malpresentations and malpositions

The most frequent and most favourable presentation is a well flexed head in the occipito-anterior position. In a malpresentation, there is usually a poor fit between the presenting part and the maternal pelvis. The presenting part is poorly applied to the cervix. Contractions are usually ineffective in achieving progress of labour.

Disproportion

If labour persists with disproportion, it may become arrested or obstructed. Disproportion occurs because:

You may be able to identify disproportion early in some cases: for example, with a hydrocephalic head or a large baby in a woman with an abnormal pelvis because, for instance, of a history of malformation or trauma to the pelvis. In most cases, however, disproportion is a diagnosis of exclusion: that is, after you have excluded poor uterine contractions and malpresentations.

The best test for an adequate pelvis is a trial of labour. Clinical pelvimetry is of limited value.

Chart progress on the partograph (Figure 11.5, pages 11–6 and 11–7) to obtain early warning of disproportion. When arrested labour is not recognized and becomes prolonged, cephalopelvic disproportion leads to obstruction. Evidence of obstructed labour includes arrested dilatation or descent with:

Figure 11.5
Figure 11.6
Figure 11.7
::	Large caput and excessive moulding
::	Presenting part poorly applied to cervix or cervix is oedematous
::	Ballooning of the lower uterine segment and formation of a retraction band
::	Maternal and fetal distress
::	Prolonged labour without delivery.

ASSESSMENT AND DIAGNOSIS

When a woman presents with intermittent abdominal pains, ask the following questions:

Assess the woman’s general condition:

Palpate for uterine contractions. If the woman has at least 2 uterine contractions lasting more than 20 seconds over 10 minutes, do a vaginal examination to assess cervical effacement and dilatation.

If the cervix is not dilated on first examination, it may not be possible to make a diagnosis of labour. If contractions persist, re-examine the woman after 4 hours for cervical changes. At this stage, if there is effacement and dilatation, the woman is in labour; if there is no change, make a diagnosis of false labour.

Diagnose labour only if there has been effacement and dilatation. An incorrect diagnosis of labour in this situation can lead to unnecessary anxiety and interventions.

First stage

Latent phase

Active phase

Second stage

Early phase (non-expulsive)

Late phase (expulsive)

Carry out vaginal examinations at least once every 4 hours in the first stage of labour and plot the findings on the partograph. The partograph is very helpful in monitoring the progress of labour and in the early detection of abnormal labour patterns.

More frequent vaginal examinations may be required when:

At each vaginal examination, record the following:

Assess progress in labour by:

Assess fetal condition by:

If the membranes are ruptured, check the colour of fluid. Greenish-yellow fluid, blood stained fluid or no fluid are suggestive of placental insufficiency and possibly fetal compromise.

Findings suggestive of satisfactory progress in labour

Findings suggestive of unsatisfactory progress in labour

Findings suggestive of risks to the fetus