Twin birth — structured SAQ (15 marks)

(a) Admission checklist with reasoning (4 marks)

Half a mark for each item, half a mark for the reason, to a maximum of four. ^[1][3]

• Confirm presentation of both twins by ultrasound on admission — not by palpation and not from last week's scan; the lie can change in labour and it sets the plan for twin 2.
• Confirm chorionicity from the first-trimester record — it sets the surveillance history and confirms the timing is appropriate.
• Establish dual continuous electronic fetal monitoring, ideally with a fetal scalp electrode on twin 1 so the two traces are demonstrably different — the commonest monitoring error is recording the same heart on both channels.^[3]
• Intravenous access and group and hold, with an oxytocin infusion prepared but not running — the overdistended uterus is a postpartum haemorrhage risk.
• Epidural discussed and encouraged — not for pain alone, but because intrauterine manipulation of twin 2 is far safer and faster with a working block already in place.^[3]
• The room: ultrasound machine present, two resuscitaires and two neonatal teams, anaesthetist aware, theatre immediately available, and an experienced obstetrician present for the second stage.^[1]

(b) The interval and a breech twin 2 with a reassuring CTG (5 marks)

One mark each for: no bolus uterotonic; immediate ultrasound; stabilising the lie abdominally; oxytocin and amniotomy rules; and the conduct of an assisted breech birth. ^[1][3]

1. No bolus uterotonic after twin 1. The uterus must keep working for twin 2; a bolus risks precipitate separation or constriction around twin 2. Clamp and clearly label the cord, leaving length for placental studies.^[3]
2. Immediate ultrasound for the lie and presentation of twin 2, and reassess the CTG.^[1]
3. Stabilise the lie abdominally — an assistant holds twin 2 in a longitudinal axis to prevent it swinging transverse in the suddenly roomy uterus.^[1]
4. Oxytocin and amniotomy: if contractions have faded, start or increase the oxytocin infusion; perform amniotomy only once the presenting part is fixed in the pelvis, never over a high presenting part (cord prolapse risk).^[3]
5. Conduct of a breech twin 2 with a reassuring CTG: assisted breech birth — hands off, no traction, deliver to the scapulae, Lövset for the arms if extended, Mauriceau-Smellie-Veit or forceps for the after-coming head. Active third-stage management with an oxytocin infusion once twin 2 is born.^[3]

(c) Internal podalic version and breech extraction (4 marks)

One mark for setup, one mark for the technique in sequence, and two marks for the three classic errors. ^[3][5]

Setup (1 mark): adequate anaesthesia (the epidural, topped up, or general anaesthesia), the cervix fully dilated, and — critically — membranes intact if at all possible, because intact membranes give room to manoeuvre and a cushion of liquor. Ultrasound first to confirm the lie and locate the head, spine and feet.^[3]

Technique in sequence (1 mark): the abdominal hand (assistant or your free hand) holds the fetal head at the fundus throughout; the vaginal hand introduces through the cervix, follows the trunk to the lower limbs, and grasps both feet together where possible — a foot is identified by the heel and the short straight line of the toes. Bring the feet down through the cervix with steady traction, rupture the membranes once the feet are through, and extract as a breech: trunk to the scapulae, arms by Lövset if needed, head by Mauriceau-Smellie-Veit or forceps.^[3]

The three classic errors (any three, totalling two marks): ^[3][5]

• Pulling on a hand instead of a foot (a hand has a mobile thumb and long fingers; a foot has a heel).
• Grasping one foot when both were reachable, leaving an extended leg splinting the birth.
• Rupturing the membranes before the feet are through the cervix, which converts the manoeuvre into an emergency caesarean under general anaesthesia.^[3][5]

(d) Twin Birth Study and RANZCOG position on a non-cephalic twin 2 (2 marks)

One mark for the trial result, one mark for the RANZCOG position. ^[1]

• Twin Birth Study (Barrett, NEJM 2013): 2804 women between 32+0 and 38+6 weeks with twin 1 cephalic were randomised to planned caesarean or planned vaginal birth; the composite of fetal or neonatal death or serious neonatal morbidity was 2.2% versus 1.9% (OR 1.16, 95% CI 0.77 to 1.74, P=0.49) — no difference. A non-cephalic second twin was not an exclusion.^[1]
• RANZCOG C-Obs 11 position: routine caesarean for a breech second twin is not recommended, at term or preterm. The mode is set by the presentation of twin 1; the preparation is set by the presentation of twin 2.^[1]