Surgical Care at the District Hospital
Part 1 2 3 4 5 6 Primary Trauma Care Manual
Emergency Obstectric Care
Hypertension in Pregnancy
Hypertension
Assessment and management
Delivery
Postpartum care
Chronic hypertension
Complications
Management of Slow Progress of Labour
General principles
Slow progress of labour
Progress of labour
Operative procedures
Bleeding in Pregnancy and Childbirth
Bleeding
Diagnosis and initial management
Specific management
Procedures
Aftercare and follow-up
Slow Progress of Labour
 




Slow progress of labour has three fundamental causes:

:: Poor uterine contractions
:: Malpresentations and malpositions
:: Disproportion between the fetal size and pelvic size.

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:

:: A frequency of 2 to 4 in 10 minutes
:: A duration of 30 to 60 seconds
:: Progressive effacement and dilatation in the latent phase
:: Progressive dilatation of at least 1 cm/hour in the active phase
:: Progressive descent of the fetal presentation.

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:

:: The baby is too large
:: The pelvis is too small.
:: Progressive effacement and dilatation in the latent phase
:: Progressive dilatation of at least 1 cm/hour in the active phase
:: Progressive descent of the fetal presentation.

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 11.5

Figure 11.6
Figure 11.6

Figure 11.7
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:

:: Is this woman in labour?
:: If she is in labour, what is the phase of labour?
:: What is the presentation of the fetus?
:: Are the membranes ruptured? If so, how long ago?

Assess the woman’s general condition:

:: Is she in pain? Is she distressed?
:: Check pulse, blood pressure and hydration (tongue, urine output), temperature
:: Does she have any medical problems?

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

:: Cervix less than 4 cm dilated.


Active phase

:: Cervix between 4 cm and 10 cm dilated
:: Rate of cervical dilatation at least 1 cm/hour
:: Effacement is usually complete
:: Fetal descent through birth canal begins.


Second stage

Early phase (non-expulsive)

:: Cervix fully dilated (10 cm)
:: Fetal descent continues
:: No urge to push.


Late phase (expulsive)

:: Fetal presenting part reaches the pelvic floor and the woman has the urge to push
:: Typically lasts <1 hour in primigravidae and <30 minutes in multigravidae.

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:

:: Membranes rupture
:: There is fetal distress
:: The woman enters the second stage of labour.

At each vaginal examination, record the following:

:: Effacement and dilatation
:: Presenting part and station
:: Colour and odour of liquor.

Assess progress in labour by:

:: Measuring changes in cervical effacement and dilatation in the latent phase
:: Measuring the rate of cervical dilatation in the active phase
:: Assessing fetal descent in the second stage.


Assess fetal condition by:

:: Checking the fetal heart rate during or immediately after a contraction
:: Listening in to the fetal heart for one full minute:
– Every half hour in the active phase
– After every 5 minutes in the second stage.
:: Listening more frequently if an abnormality is detected: while the normal fetal heart rate is between 120 and 180 beats/minute, rates of <100 or >180 are suggestive of fetal intolerance of labour or distress.
:: Listening for the fetal heart rate recovery after contractions: repetitive slow recovery indicates fetal distress.


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

:: Regular contractions of progressively increasing frequency and duration
:: Rate of cervical dilatation at least 1 cm/hour in the active phase of labour
:: Satisfactory descent with pushing in the expulsive phase
:: Cervix closely applied to fetal head.

Findings suggestive of unsatisfactory progress in labour

:: Irregular, infrequent and weak contractions
:: Cervical dilatation rate slower than 1 cm/hour in the active phase
:: No descent with pushing in the expulsive phase
:: Presenting part applied loosely to the cervix.


Findings suggestive of risks to the fetus

:: Bloodstained amniotic fluid
:: Greenish-yellow coloured amniotic fluid
:: Fetal heart rate abnormalities, such as decelerations, tachycardias or delayed recovery of fetal heart rate after contraction.

 



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