Prolonged Second Stage of Labour

Prolonged second stage of labour is a second stage, from full dilatation to birth, that lasts more than 3 hours in a first labour or more than 2 hours in a later labour, with one extra hour allowed with an epidural. It results from ineffective pushing, malposition, disproportion, a large baby or soft tissue resistance. It matters because the longer the second stage, the higher the risk of fetal acidosis, severe tears, haemorrhage and infection, though most women deliver safely when the head is descending and monitoring is good.

• Risk factors: first labour, epidural, large baby, occiput posterior position, obesity, exhaustion, high head at full dilatation.
• Progress in descent and rotation matters more than the clock.
• Fetal wellbeing decides how long to wait.

Women have strong contractions and push for many hours, becoming exhausted, with a head that moves slowly or not at all. The vulva may be swollen with caput visible but no crowning.

• Slowly advancing or static head on repeated examination.
• Maternal ketosis, dehydration and a full bladder.
• Differential diagnosis: arrest of descent, cephalopelvic disproportion, occiput posterior or transverse position, poor pushing from epidural, rigid perineum, shoulder impaction, chorioamnionitis.
• Complications: fetal acidosis, hypoxia, perineal trauma, postpartum haemorrhage, chorioamnionitis, uterine atony, urinary retention, pelvic floor injury, obstetric fistula, caesarean section.

The diagnosis is made from the time of full dilatation and the rate of descent on repeated examination.

• Record the time of full dilatation and the start of active pushing; examine every hour for station, position, caput and moulding.
• Cardiotocography; fetal scalp lactate where available (above 4.8 mmol/L abnormal).
• Maternal pulse, temperature, urine output, ketones; bladder palpation.
• Ultrasound for position and estimated weight; assessment of the bony pelvis.

The principle is to continue while the head is descending and fetal wellbeing is normal, and to assist or operate when descent stops.

• Supportive: upright, kneeling or side lying positions; delayed pushing for 1 to 2 hours with a dense epidural, then active pushing; empty the bladder; Ringer's lactate 1 litre IV over 1 hour for dehydration; encouragement; continuous cardiotocography; senior review at the limit of time.
• Pharmacological: oxytocin 10 IU in 1 litre Ringer's lactate (10 mU/mL) started at 12 mL per hour (2 mU/minute) and doubled every 30 minutes to a maximum of 192 mL per hour (32 mU/minute) for weak contractions without disproportion; lignocaine 1 percent 10 to 20 mL (maximum 3 mg/kg, not above 200 mg) for perineal infiltration; amoxicillin-clavulanate 1.2 g IV as a single dose after operative vaginal delivery; ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily for chorioamnionitis; oxytocin 10 IU IM after birth, then 20 IU in 1 litre at 125 mL per hour for 4 hours; tranexamic acid 1 g IV over 10 minutes if bleeding exceeds 500 mL.
• Procedures: vacuum or forceps when the head is engaged and at station +2 or lower (vacuum: up to 3 pulls, 2 detachments, 20 minutes in total; forceps: up to 3 pulls); episiotomy when needed; caesarean section for a high head, disproportion, failed assisted delivery or fetal compromise.
• Special groups: epidural analgesia allows 1 extra hour; a uterine scar uses oxytocin only with senior review and continuous monitoring.
• Red flags: abnormal fetal heart rate, thick meconium, fever above 38 degrees Celsius, scar pain, bleeding, maternal exhaustion, bandl ring.
• Follow-up: bladder catheter for 24 hours after assisted birth; examine for tears and repair; review at 1 week and 6 weeks; ask about bladder, bowel and sexual function.