Define and describe the causes, clinical features, complications and management of obstructed Labour.

The partogram detects obstruction before these complications occur.

Definition

Obstructed labour is one in which, despite good uterine contractions, there is no advance of the presenting part owing to a mechanical obstruction to descent. Unrelieved, it leads to serious maternal and fetal morbidity and mortality.

Obstructed Labour - Causes & Signs

Causes

• Fault in the passage — contracted pelvis / cephalopelvic disproportion, pelvic tumours (fibroid, ovarian), a high assimilation pelvis, and soft-tissue obstruction (stenosis, full bladder/rectum).
• Fault in the passenger — malpresentations and malpositions (shoulder/transverse lie, brow, persistent occipito-posterior, face mento-posterior), a big baby, hydrocephalus, locked twins and fetal tumours.

Clinical Features

• General/maternal — exhaustion and maternal distress — dehydration, ketoacidosis, rising pulse and temperature, and scanty, concentrated urine.
• Abdominal — the uterus is tonically contracted and tender
• a Bandl's (pathological retraction) ring rises towards the umbilicus, separating the upper from the over-stretched lower segment
• fetal parts are difficult to feel and the fetal heart is often absent.
• Vaginal — a dry, hot vagina, an oedematous cervix and vulva, a large caput and excessive moulding, the presenting part jammed and not advancing, and sometimes a foul discharge.

Investigations

Mainly clinical, supported by haemoglobin and electrolytes (dehydration), blood grouping and cross-match, urine for ketones, and ultrasound to confirm the presentation and fetal viability. Continuous watch is kept for the warning signs of impending rupture — a rising Bandl's ring, severe lower-segment tenderness, haematuria and maternal restlessness.

Complications

Maternal — rupture of the uterus, obstructed-labour sepsis, postpartum haemorrhage (atony), genital fistulae (vesico-vaginal/recto-vaginal) from pressure necrosis, obstetric (foot-drop) palsy, and death. Fetal — asphyxia, intra-uterine death, and birth injury.

Management

Prevention

The condition is largely preventable — antenatal detection of disproportion/malpresentation, and use of the partograph to detect arrest early and refer in time.

Treatment of established obstruction

• Resuscitate — large-bore IV fluids to correct dehydration and electrolytes, broad-spectrum antibiotics, bladder catheterisation, and blood arranged.
• Relieve the obstruction by delivery — if the fetus is alive (or dead but undeliverable vaginally), caesarean section. If the fetus is dead and conditions are suitable, a destructive operation (craniotomy) may be done by the experienced; caesarean is safer when in doubt.
• Manage complications — repair uterine rupture (or hysterectomy), treat sepsis, watch for and manage postpartum haemorrhage, and arrange later fistula repair.

WHY Obstructed Labour Is a Preventable Catastrophe

The tragedy of obstructed labour is that it happens at all, when it is so easily prevented. It is not a sudden event but the end point of a labour that has been failing for hours — the presenting part cannot descend despite good contractions, because of cephalopelvic disproportion, malpresentation, a malposition or a pelvic tumour. Every hour of obstruction inflicts damage: the upper segment retracts and thickens while the lower segment stretches and thins, producing the pathological retraction (Bandl's) ring — the visible warning that the uterus is about to rupture; and the soft tissues of the bladder, vagina and rectum are crushed between the fetal head and the pelvic bones, becoming ischaemic and sloughing to produce an obstetric fistula — a lifelong, socially devastating injury. Meanwhile the fetus dies of asphyxia, and the mother of rupture, sepsis or haemorrhage. Yet all of this unfolds slowly and visibly, and can be prevented entirely by the simple act of plotting the labour on a partogram and acting when the action line is crossed. Recognising that obstructed labour is the price of unmonitored labour explains why the partogram, and access to emergency caesarean section, are the true remedies.

WHY the Management Is Never 'push Harder'

A crucial rule is why oxytocin must never be given to augment an obstructed labour — an error that kills. Faced with a labour that is not progressing, the instinct is to strengthen the contractions. But if the cause is true obstruction (a head that cannot pass the pelvis), stimulating the uterus does not overcome the obstruction — it merely drives the already-retracting upper segment harder against an immovable object, thinning the lower segment further until the uterus ruptures, killing the fetus and often the mother. This is why obstructed labour is an absolute contraindication to oxytocin, and why the signs of impending rupture — a rising, tender Bandl's ring, an exhausted and distressed mother, haematuria, fetal distress or death — must be recognised as an emergency. The correct management is immediate resuscitation (intravenous fluids, blood, antibiotics, catheterisation) and delivery by caesarean section, whatever the state of the fetus — because the operation is being performed to save the mother. Understanding that the uterus must be relieved rather than driven explains why the treatment of obstructed labour is always delivery, never augmentation.

• Obstructed labour: the presenting part fails to descend despite good contractions — from CPD, malpresentation, malposition or a pelvic tumour.
• Signs: prolonged labour, an exhausted dehydrated mother, tachycardia, ketosis, oliguria/haematuria, oedematous vulva, excessive caput and moulding, fetal distress.
• The pathological retraction (BANDL'S) ring signals impending uterine rupture — an emergency.
• Never give oxytocin to an obstructed labour — it causes uterine rupture; resuscitate and deliver by caesarean section.
• Sequelae: uterine rupture, sepsis, PPH, obstetric (vesicovaginal) fistula and fetal death — all preventable with the partogram.