#Background
In the first few minutes after birth and whilst the umbilical cord remains intact and patent, the newborn pēpi receives a passive placental transfusion of warmed, oxygenated autologous blood. To enable this, deferring umbilical cord clamping until at least one minute after birth is considered standard of practice for term pēpi and early cord clamping (<60 seconds after birth) should only be considered for pēpi that require immediate positive-pressure ventilation.1 For preterm pēpi, there has been concern that this practice may delay time to neonatal assessment and resuscitation and increase circulating blood volume and hence potentially negatively impact on outcome. However, there are also a number of potential advantages of this passive placental transfusion time for the pēpi that may contribute to improved outcomes. Deferred (also referred to as delayed) cord clamping (≥60 seconds) may increase red cell mass and hence improve oxygen carrying capacity; increase mesenchymal stem cells and hence alter inflammatory response; maintain cardiac output, blood pressure and oxygenation until their own breathing is established; and avoid unnecessary intervention such as intubation and mechanical ventilation as the majority of preterm pēpi will establish their own breathing within the first minute of life.2
This ‘no cost’ intervention has been evaluated in the preterm birth setting in many randomised trials. The largest of which is the Australian Placental Transfusion Study (APTS).3 This trial of 1566 liveborn pēpi born at <30 weeks gestation included several sites in Aotearoa.3 The findings of the APTS are included in a 2017 systematic review and meta-analysis of 18 randomised trials and 2835 pēpi, assessing the impact of deferred (≥30 seconds) and early (<30 seconds) cord clamping on pēpi born at <37 weeks gestation (excluding trials with cord milking).2 In most trials deferred cord clamping was for ≥60 seconds. Deferred cord clamping reduced hospital mortality (RR 0.68, 95% CI 0.52-0.90) and this effect was consistent for gestational ages <28 weeks (RR 0.70, 95% CI 0.51-0.95, n=996 in 3 trials).2 It was also associated with a reduced incidence of low Apgar score at 1 minute (but not at 5 minutes) and had no effect on intubation for resuscitation, neonatal unit admission temperature, mechanical ventilation, intraventricular haemorrhage, brain injury, chronic lung disease, necrotising enterocolitis, late onset sepsis or retinopathy of prematurity.2 Deferred cord clamping was associated with an increased peak haematocrit (2.73%, 95% CI 1.94-3.52) and reduced the proportion of infants having blood transfusion by 10% (95% CI 6-13).2
The increase in haematocrit is unlikely to be harmful for the majority of preterm pēpi but this polycythaemia and subsequent hyperbilirubinemia may be of more concern for pēpi already at risk of polycythaemia (e.g. recipient twin in twin-to-twin transfusion syndrome) and so caution should be used where this may be a concern. Although polycythaemia can generally be managed safely, other potential risks mean there is ongoing debate regarding the use of cord milking (physically expressing blood from the umbilical cord) for the preterm pēpi. In particular, for extreme preterm pēpi, where this practice has been associated with an increased risk of intraventricular haemorrhage.4
Deferred cord clamping has not been associated with any harmful effects for wāhine/people, including no increase in the use of uterotonic agents or the number of blood transfusions.3 Early cord clamping to allow controlled cord traction does not provide additional benefit in the prevention of postpartum haemorrhage and is not recommended.1
#Recommendations and Practice
Guideline Recommendations
Umbilical cord clamping practice at preterm birth
Deferred cord clamping is recommended:
- For all preterm gestational ages, including at the threshold of survival (23+0 to 24+6 weeks).
- Regardless of the mode of birth, number of pēpi, indication for preterm birth or type of analgesia/anaesthesia.
Contraindications/relative contraindications to deferred cord clamping include:
- Pēpi requires immediate resuscitation (determined in consultation with the neonatal team).
- Major concern for wahine/person wellbeing – haemorrhage, shock, seizure.
- Whenua/placental circulation is no longer intact – cord evulsion, placental abruption, placental incision for placenta praevia, uterine inversion, or cord pulsation has ceased.
- Known vasa praevia.
- Monochorionic twin pregnancies with confirmed twin-to-twin transfusion syndrome or twin anaemia-polycythaemia sequence (TAPS).
- Fetal hydrops.
- Deferred cord clamping does not increase the risk of postpartum haemorrhage.
- Oxytocic drugs should be used in the usual way. They can be given before or after cord clamping.
- Cord milking is not recommended for preterm pēpi.
Good Practice
Umbilical cord clamping practice at preterm birth
- There is insufficient evidence to confirm the most effective interval from birth to cord clamping for preterm pēpi, 60 seconds is advised.
- At the time of birth, pēpi born <30 weeks gestation should be placed on the bed (after vaginal birth) or on the thigh/abdomen of the wahine/person (after caesarean section birth). The cord should not be palpated. A stopwatch or resuscitaire clock should be used to time 60 seconds and this time should be recorded in the clinical notes. The cord should then be clamped in the usual way.
- At the time of birth, for pēpi born at later preterm gestations, skin-to-skin on the abdomen/chest of the wahine/person may be considered. The cord should not be palpated. A stopwatch or resuscitaire clock should be used to time at least 60 seconds and this time should be recorded in the clinical notes. The cord should then be clamped in the usual way.
- Simultaneous essential neonatal care should be provided during delayed cord clamping including stimulation, drying and thermal control of the pēpi.
- Wāhine/people and whānau should be provided with verbal and written information on deferred cord clamping.
- Interpreter services and cultural support should be available and offered to all wāhine/people and whānau to support the provision of information.
The Carosika Whānau Information on Deferred Cord Clamping at Preterm Birth may be used to support conversations with wāhine/people and whānau.
Published: October 2024 | PDF
The Carosika Deferred Cord Clamping Standard Operating Procedure may be used to support institutional practice change and as an aide memoire for clinicians.
Published: October 2024 | PDF
Whānau may find it useful to watch this short video sharing the experience of participating in the APTS Trial, a study which provides much of the evidence that informs us.
This media story provides a brief commentary on the APTS Trial, a study that provides much of the evidence that informs our practice, with links to useful publications.
Whānau may also find it useful to watch this Whānau Story after an extreme preterm birth and deferred cord clamping.
#Auditable Standards
- Proportion of pēpi live born at 23+0 to 33+6 weeks gestation that have cord clamping information documented in the clinical record.
- Proportion of pēpi live born at 23+0 to 33+6 weeks gestation that have deferred cord clamping for at least 60 seconds.
Standards should be considered across your population and by ethnic group to allow objective assessment of equity in practice.
The Carosika Deferred Cord Clamping Audit Tool document may be used to be support hospitals and healthcare professionals to undertake local practice audit on cord clamping for preterm pēpi.
Published: October 2024 | PDF