Nuchal Cord

A nuchal cord is a loop of umbilical cord around the fetal neck, common at birth and on antenatal ultrasound. It results from a long cord and fetal movement. It matters because most are harmless, while a tight cord can cause fetal heart rate decelerations, hypoxia and, rarely, stillbirth.

• Risk factors: long cord, polyhydramnios, male fetus, active fetus, multiparity.
• A single loop is common at birth.
• Routine intervention is not needed when the tracing is normal.

Most women have no symptoms. The cord may cause variable decelerations in labour, reduced fetal movement in late pregnancy, a baby delivered with the cord around the neck or a transient delay in descent.

• Variable decelerations with contractions.
• Often found only when the head is delivered.
• Differential diagnosis: cord compression of other cause, true knot, short cord, abruption, fetal distress from other cause.
• Complications: fetal heart rate decelerations, fetal hypoxia, low Apgar score, emergency caesarean section, stillbirth, neonatal asphyxia.

The approach is clinical with ultrasound and cardiotocography.

• Ultrasound with colour Doppler: cord vessels forming a "U" or ring around the neck; confirm in two planes.
• Cardiotocography for variable decelerations with a slow return to baseline.
• At birth: feel for the cord around the neck once the head is delivered.
• Umbilical cord blood gas at birth in babies born with a tight cord.

The principle is observation, with continuous monitoring in labour and a safe technique for freeing the cord at birth.

• Supportive: no action for a nuchal cord found antenatally with normal fetal movement; daily fetal movement counts; left lateral position in labour; continuous cardiotocography for repeated decelerations.
• Pharmacological: oxytocin 10 IU IM at birth; neonatal resuscitation drugs if needed: adrenaline 0.01 to 0.03 mg/kg IV (0.1 to 0.3 mL/kg of 1 in 10,000) when heart rate stays below 60 per minute after 30 seconds of effective ventilation and compressions.
• Procedures: at birth of the head, slip a loose loop over the head or over the shoulders; for a tight cord use the somersault manoeuvre (keep the head near the thigh and deliver the body in a somersault away from the cord) or clamp with two clamps and cut between them, then deliver quickly; do not pull on the cord; neonatal bag and mask ventilation at 30 to 60 breaths per minute with chest compressions in a ratio of 3 to 1 if the heart rate stays below 60 per minute; caesarean section only for pathological tracing.
• Red flags: persistent or prolonged decelerations, bradycardia, reduced fetal movements, meconium stained liquor with an abnormal tracing, floppy baby at birth.
• Follow-up: umbilical cord blood gas at birth; newborn Apgar score and neurological examination; observation for 12 to 24 hours if depressed at birth.