Prolonged First Stage of Labour

Prolonged first stage of labour is an active first stage (cervix 5 cm or more dilated with regular contractions) that lasts more than 12 hours, or in which the partograph line crosses the action line 4 hours to the right of the alert line. It results from weak or uncoordinated contractions, malposition, disproportion or a large baby. It matters because exhaustion, infection, obstructed labour, uterine rupture and caesarean section follow when it is not corrected.

• Risk factors: first labour, obesity, occiput posterior or transverse position, large baby, dehydration, early epidural, anxiety.
• Dilatation of less than 1 cm per hour crosses the alert line.
• Early correction lowers caesarean section rates.

Women have regular painful contractions for many hours with slow cervical progress, becoming tired, dehydrated and distressed. Examination shows a cervix dilating slowly, caput and sometimes moulding.

• Partograph line to the right of the alert line.
• Maternal pulse above 100 per minute and ketonuria.
• Differential diagnosis: inadequate uterine activity, cephalopelvic disproportion, malposition, cervical dystocia, abnormal lie, chorioamnionitis, obstructed labour.
• Complications: exhaustion, ketoacidosis, chorioamnionitis, obstructed labour, uterine rupture, fetal hypoxia, caesarean section, postpartum haemorrhage, obstetric fistula.

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

• Dilatation, effacement, station, position, caput, moulding, membranes and liquor colour.
• Contraction frequency and duration (3 to 5 in 10 minutes lasting 40 to 60 seconds is adequate).
• Cardiotocography; maternal pulse, temperature, blood pressure, hydration and urine ketones.
• Abdominal palpation for head level and lie; ultrasound for position and estimated fetal weight where needed.

The principle is to exclude obstruction first, then correct weak contractions with amniotomy and oxytocin, and operate if progress fails.

• Supportive: Ringer's lactate 1 litre IV over 1 to 2 hours; empty the bladder; walking, upright and side lying positions; one to one support; analgesia (epidural or pethidine 50 to 100 mg IM 4-hourly, maximum 400 mg in 24 hours); continuous cardiotocography on oxytocin.
• 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), aiming for 3 to 5 contractions in 10 minutes lasting 40 to 60 seconds, stopped 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 of membranes for 18 hours or more; ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily for chorioamnionitis, with metronidazole 500 mg IV 8-hourly added after caesarean section; cefazolin 2 g IV before caesarean section; oxytocin 10 IU IM after birth, then 20 IU in 1 litre at 125 mL per hour for 4 hours.
• Procedures: amniotomy when the head is engaged; caesarean section for obstruction, no progress after 4 hours of adequate oxytocin, or fetal compromise.
• Special groups: a uterine scar or grand multiparity uses oxytocin only with senior review and continuous monitoring because of uterine rupture; chorioamnionitis needs delivery whatever the dilatation.
• Red flags: tachysystole, abnormal fetal heart rate, fever above 38 degrees Celsius, scar pain, bandl ring, maternal exhaustion, bleeding, hot dry vagina.
• Follow-up: cervical examination 2-hourly on oxytocin; maternal temperature 4-hourly; bladder catheter for 24 hours after caesarean section or 7 to 14 days after obstructed labour; review at 6 weeks.