Protracted Active Phase

Protracted active phase is slow dilatation in the active phase of labour, at a rate below 1 cm per hour, shown by the partograph line crossing the alert line, but without a complete arrest. It results from inadequate or uncoordinated uterine contractions, malposition, a large baby or a tight pelvis. It matters because most cases respond to simple measures, while late action leads to arrest, infection and caesarean section.

• Risk factors: first pregnancy, obesity, occiput posterior or transverse position, large baby, dehydration, epidural, anxiety.
• Active phase starts at 5 cm dilatation with regular contractions.
• Early correction lowers caesarean section rates.

Women have regular painful contractions with slow progress, becoming tired. The cervix is dilating but more slowly than 1 cm per hour.

• Partograph line crossing the alert line.
• Good fetal heart rate in most.
• Differential diagnosis: normal slow active phase, inadequate uterine activity, malposition, cephalopelvic disproportion, cervical dystocia, chorioamnionitis.
• Complications: progression to arrest, prolonged labour, exhaustion, chorioamnionitis, caesarean section, assisted delivery, postpartum haemorrhage.

The approach is partograph review with a cervical examination every 2 to 4 hours.

• Cervical dilatation over time, effacement, station, caput, moulding and position; membrane status and liquor colour.
• Contraction count (3 to 5 in 10 minutes lasting 40 to 60 seconds is adequate).
• Cardiotocography; maternal pulse, temperature, urine ketones and hydration.
• Abdominal palpation for head level and lie; ultrasound for occiput position and estimated weight if needed.

The principle is amniotomy, hydration, position change and oxytocin for inadequate contractions, with reassessment 2-hourly.

• Supportive: hydration (oral fluids or Ringer's lactate 1 litre IV over 2 hours); empty bladder; upright, walking, hands and knees or side lying positions; one to one support; analgesia (epidural or pethidine 50 to 100 mg IM 4-hourly); continuous cardiotocography on oxytocin.
• Pharmacological: oxytocin starting at 2 mU/minute and doubling every 30 minutes to a maximum of 32 mU/minute, aiming for 3 to 5 contractions in 10 minutes lasting 40 to 60 seconds; stop for tachysystole or fetal distress; benzylpenicillin 5 million units IV then 2.5 million units 4-hourly in labour for group B streptococcus or rupture for 18 hours or more; ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily for chorioamnionitis; cefazolin 2 g IV before caesarean section; oxytocin 10 IU IM at birth then infusion of 20 IU in 1 litre sodium chloride 0.9 percent at 125 mL per hour for 4 hours.
• Procedures: amniotomy when the head is engaged and membranes are intact; manual rotation of a malpositioned head when fully dilated; caesarean section for no progress after 4 hours of adequate oxytocin, for cephalopelvic disproportion, or fetal compromise.
• Special groups: women with a previous caesarean section have oxytocin with senior review and continuous monitoring because of the risk of uterine rupture; grand multiparas avoid oxytocin unless closely monitored.
• Red flags: tachysystole, abnormal fetal heart rate, fever above 38 degrees Celsius, scar pain, bandl ring, bleeding, maternal exhaustion.
• Follow-up: cervical examination 2-hourly; maternal temperature 4-hourly; postnatal care of the perineum and bladder.