Obstetrics – intrapartum care, operative delivery and obstetric emergencies
Introduction
This domain covers the diagnosis and progress of labour, fetal monitoring, the three stages and their complications, operative vaginal delivery and caesarean section, and the emergencies where minutes decide outcome.
Monitoring and progress
- Active first stage: regular painful contractions with cervical change; record dilatation, station, position and caput on the partograph. Dilatation under 0.5 cm/h in the active phase suggests dystocia.
- CTG (FIGO 2015): baseline 110–160 bpm, variability 5–25 bpm, accelerations present, no decelerations is normal. Variability under 5 bpm with recurrent late or prolonged decelerations is pathological and calls for intrauterine resuscitation - left lateral position, stop oxytocin, IV fluid, tocolysis for hyperstimulation, exclude cord prolapse - then delivery if no recovery.
- Second stage: passive descent until the head reaches the perineum, then active pushing; expected delivery within about 1 hour in a nullipara and 30 minutes in a multipara, with allowance for regional analgesia.
Third stage and haemorrhage
- Active management: oxytocin 10 IU IM with the anterior shoulder, controlled cord traction, uterine palpation.
- Postpartum haemorrhage ≥500 mL after vaginal birth or ≥1000 mL after caesarean: uterine massage, oxytocin, tranexamic acid 1 g, carboprost or misoprostol, balloon tamponade, then surgical escalation.
Operative delivery
- Vacuum or forceps requires full dilatation, an engaged head with known position, empty bladder, adequate analgesia and consent; sequential instruments increase neonatal trauma.
- Caesarean section audited by Robson classification; category 1 for immediate threat to mother or fetus.
- Shoulder dystocia: call for help, McRoberts manoeuvre, suprapubic pressure, then internal rotational manoeuvres, all-fours position, cleidotomy as last resort.
Worked example
A nullipara at 6 cm on oxytocin has a CTG with baseline 150 bpm, variability 3 bpm and recurrent late decelerations. This is pathological, not suspicious: variability under 5 bpm with repetitive late decelerations means fetal hypoxaemia. Stop the oxytocin, turn her left lateral, give IV fluid, exclude hyperstimulation and cord prolapse, and if there is no improvement prepare category 1 caesarean section.
Traps
- Treating variable decelerations as hypoxaemia - most reflect cord compression and respond to position change.
- Calling obstructed labour from slow progress without checking position and caput.
- Attempting forceps with an unengaged head.
- Delivering a woman with a previous classical caesarean outside a unit with immediate theatre access.