Precipitate Labour

Precipitate labour is labour, from the start of regular contractions to birth, that lasts less than 3 hours, with cervical dilatation faster than 5 cm per hour in a first labour or 10 cm per hour in a later labour. It results from very strong contractions, a roomy pelvis, a small baby or low resistance of the soft tissues. It matters because rapid birth causes cervical and perineal tears, postpartum haemorrhage, uterine inversion and rupture, fetal injury and unattended birth.

• Risk factors: multiparity, previous precipitate labour, preterm or small baby, abruption, cocaine use, oxytocin or misoprostol, chronic hypertension.
• Often occurs outside a facility.
• The baby may need resuscitation after a sudden birth.

Women have intense, frequent contractions with sudden urge to push and rapid descent, sometimes with birth in transit. Examination shows a fully dilated cervix at first assessment.

• Contractions every 1 to 2 minutes, very painful.
• Sudden bearing down with the head crowning.
• Differential diagnosis: second stage of a normal fast labour, abruption with hypertonic uterus, uterine hyperstimulation, preterm labour, uterine rupture.
• Complications: cervical, vaginal and perineal lacerations, postpartum haemorrhage, uterine atony, uterine inversion, birth injury (cephalohaematoma, clavicle fracture, intracranial haemorrhage), cord rupture, neonatal hypothermia, infection from unclean birth.

The diagnosis is made from the history of labour duration and the finding of a rapidly advancing second stage.

• Time of onset of contractions and of birth; examination for dilatation, station, presentation and liquor.
• Cardiotocography or intermittent auscultation after each contraction.
• After birth: inspection of the perineum, vagina and cervix for tears with good light and an assistant; uterine tone and bleeding; placenta and membranes for completeness.
• Newborn: temperature, breathing, tone, skin and skull examination for injury.

The principle is a controlled delivery of the head, a thorough search for tears and active management of the third stage.

• Supportive: left lateral or semi sitting position; panting to resist pushing between contractions; controlled delivery of the head with a hand on the perineum and flexion of the head; check for cord around the neck; support the baby and dry, wrap and place skin to skin; clean delivery kit and cut the cord after 1 to 3 minutes; keep the mother warm.
• Pharmacological: oxytocin 10 IU IM within 1 minute of birth; if bleeding continues give oxytocin 20 IU in 1 litre Ringer's lactate at 125 mL per hour for 4 hours, misoprostol 800 micrograms sublingual, and tranexamic acid 1 g IV over 10 minutes; lignocaine 1 percent 10 to 20 mL (maximum 3 mg/kg, not above 200 mg) for repair; terbutaline 0.25 mg subcutaneous once for tachysystole with fetal distress before birth; amoxicillin-clavulanate 625 mg oral 8-hourly for 5 days for third or fourth degree tears; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours); vitamin K 1 mg IM to the newborn once.
• Procedures: repair of cervical and perineal tears in theatre with good light; manual replacement of an inverted uterus (push the fundus up through the cervix) with glyceryl trinitrate 400 micrograms sublingual or terbutaline 0.25 mg subcutaneous for relaxation; hydrostatic replacement with warmed sodium chloride 0.9 percent 2 to 3 litres if manual replacement fails.
• Special groups: women with a history of precipitate labour are advised to go to a facility at the first contraction and may be offered induction in daytime at 39 weeks; unattended birth outside a facility needs transfer for checking of the genital tract and the baby.
• Red flags: heavy bleeding, uterus not contracting, a mass in the vagina (inversion), severe pain, shock, baby not breathing, floppy baby.
• Follow-up: observe the mother for 2 hours then 4-hourly for 24 hours with pulse, blood pressure and bleeding; newborn examination within 24 hours; review at 1 week and 6 weeks.