Obstructed Labour

Obstructed labour is failure of the fetus to advance through the birth canal despite strong uterine contractions, because of mechanical obstruction. Causes include cephalopelvic disproportion, malpresentation (shoulder, brow, face with chin posterior), fetal anomaly (hydrocephalus) and soft tissue obstruction (fibroids, cervical or vaginal masses). It is a leading cause of maternal death, uterine rupture, stillbirth and obstetric fistula in Kenya, especially in women who deliver at home or reach care late.

• Risk factors: adolescent mother, short stature, no antenatal care, home delivery, previous obstructed labour, malpresentation, large baby.
• A cervix that is oedematous and a bandl ring signal impending rupture.
• Early recognition on the partograph prevents most cases.

Women have a long labour with severe continuous pain, exhaustion, dehydration and fever, with a fast pulse, a tender lower abdomen, and a bandl ring (a ridge across the lower abdomen with a stretched lower segment). The vagina is hot and dry, and the urine is scanty and blood-stained.

• Caput and moulding of 3 plus, oedematous cervix, head not engaged.
• Fetal heart abnormal or absent.
• Differential diagnosis: uterine rupture, abruption, chorioamnionitis, tetanic contractions, bladder distension, malaria, severe sepsis.
• Complications: uterine rupture, vesicovaginal and rectovaginal fistula, sepsis, haemorrhage, stillbirth, foot drop from nerve injury, maternal death, long term incontinence and stigma.

The diagnosis is clinical and is made on the partograph and examination, and is confirmed at the time of delivery.

• Partograph: cervical dilatation crossing the action line, no descent despite 3 to 5 contractions in 10 minutes, caput and moulding.
• Abdominal examination: bandl ring, tender lower segment, fetal lie; vaginal examination: cervix, presentation, position, pelvis, liquor colour (meconium or blood), temperature of the vagina.
• Pulse, blood pressure, temperature, urine output and colour, ketones.
• Full blood count, malaria test, group and cross-match 2 to 4 units, creatinine, glucose; ultrasound for lie, fetal heart, hydrocephalus and fibroids.

The principle is resuscitation and immediate delivery by the safest route, with antibiotics and protection of the bladder.

• Supportive: call senior obstetric and anaesthetic help; two large-bore cannulae; Ringer's lactate 1 litre IV over 30 minutes then 1 litre over 2 hours, guided by pulse and urine output; oxygen if shocked; urinary catheter with hourly output; analgesia; no oxytocin; group and cross-match; blood transfusion for haemoglobin below 7 g/dL or shock.
• Pharmacological: ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily plus metronidazole 500 mg IV 8-hourly, started before delivery and continued until afebrile for 48 hours; cefazolin 2 g IV before caesarean section; morphine 2.5 to 5 mg IV titrated for pain; oxytocin 10 IU IM after delivery, then 20 IU in 1 litre at 125 mL per hour for 4 hours; tranexamic acid 1 g IV over 10 minutes for bleeding; paracetamol 1 g IV or oral 6-hourly (maximum 4 g in 24 hours); newborn resuscitation with bag and mask, vitamin K 1 mg IM, and benzylpenicillin 50 mg/kg IV 12-hourly plus gentamicin 5 mg/kg IV 24-hourly for suspected sepsis.
• Procedures: caesarean section for a live fetus or when vaginal delivery is not possible; vacuum delivery only if the head is low and disproportion is absent; destructive delivery (craniotomy, or decapitation for neglected shoulder presentation) by a trained operator for a dead fetus; repair of rupture or hysterectomy for uterine rupture; bladder catheter continuously for 7 to 14 days to prevent fistula.
• Special groups: a dead fetus allows destructive delivery with lower maternal risk when trained staff are present; a uterine scar with obstructed labour is assumed to have scar rupture until shown otherwise; HIV positive women continue tenofovir 300 mg, lamivudine 300 mg and dolutegravir 50 mg oral once daily.
• Red flags: bandl ring, sudden cessation of pain with shock, blood in urine, vaginal bleeding, fever above 38 degrees Celsius, pulse above 120 per minute, absent fetal heart.
• Follow-up: bladder catheter for 7 to 14 days and early fistula check; haemoglobin at 24 hours and iron; counselling about planned caesarean section in the next birth; referral to a fistula surgeon for leaking urine or stool.