Cord Presentation in Labour

Cord presentation in labour is a cord that lies below or beside the presenting part with the membranes still intact, found on vaginal examination or ultrasound in a woman in labour. It is the forerunner of cord prolapse when the membranes rupture. It matters because rupture, whether spontaneous or from amniotomy, causes cord compression within minutes.

• Risk factors: malpresentation (breech, transverse lie), unengaged head, polyhydramnios, prematurity, multiple pregnancy, long cord, low lying placenta.
• Amniotomy and vaginal examination can provoke rupture and prolapse.
• Emergency caesarean section prevents harm.

Women usually have no specific symptoms. A pulsating loop of cord is felt through the intact membranes below or beside the presenting part, and the fetal heart may show variable decelerations.

• Pulsatile cord felt in the lower segment or in front of the presenting part.
• Often accompanied by a high or abnormal presenting part.
• Differential diagnosis: cord prolapse, vasa previa, bulging membranes with a fetal limb, placenta previa, uterine contraction ring.
• Complications: cord prolapse on rupture, cord compression, fetal hypoxia, hypoxic ischaemic encephalopathy, fetal death, emergency caesarean section.

The diagnosis is made by gentle vaginal examination with ultrasound confirmation, performed only when placenta previa is excluded.

• Vaginal examination (gentle, with minimal pressure): pulsating cord below or beside the presenting part within intact membranes; feel for the fetal heart rate in the cord.
• Ultrasound with colour Doppler: cord vessels between the presenting part and the internal os.
• Cardiotocography for variable decelerations; ultrasound for lie, placental site and liquor.
• Check gestation and position; do not rupture membranes.

The principle is to avoid rupture of membranes and deliver by caesarean section before the cord prolapses, with preparation for emergency delivery.

• Supportive: stop vaginal examinations and amniotomy; knee chest or exaggerated left lateral head down position; continuous cardiotocography; two cannulae; Ringer's lactate 500 to 1000 mL IV; group and cross-match; senior obstetric, anaesthetic and neonatal teams called; prepare theatre.
• Pharmacological: terbutaline 0.25 mg subcutaneous once to reduce contractions while preparing for theatre; cefazolin 2 g IV as a single dose before caesarean section; betamethasone 12 mg IM twice, 24 hours apart, between 24 and 34 weeks and 6 days only if delivery can wait 24 hours; oxytocin 10 IU IM after birth, then 20 IU in 1 litre Ringer's lactate at 125 mL per hour for 4 hours.
• Procedures: caesarean section as soon as the diagnosis is made, with the presenting part held up by an assistant if the membranes rupture; if the cord prolapses, fill the bladder with sodium chloride 0.9 percent 500 to 750 mL through a catheter and clamp it, push the presenting part up manually and proceed to category 1 caesarean section aiming for delivery within 30 minutes (as fast as possible for bradycardia).
• Special groups: a woman who is fully dilated with the head low and membranes intact may be considered for assisted vaginal delivery by an experienced operator, with the cord checked after rupture; preterm viable fetuses have steroids if time allows.
• Red flags: rupture of membranes, palpable cord outside the membranes, bradycardia below 100 beats per minute, variable decelerations, bleeding.
• Follow-up: umbilical cord blood gas at birth; newborn Apgar score and neurological examination; observe for encephalopathy over 72 hours if depressed at birth; review at 6 weeks.