Delayed cord clamping

Previously, cutting the cord immediately after delivery was widely practiced. Current evidence suggests that delaying cord clamping is safe and can confer benefits to term and preterm infants and is now recommended as standard practise. However, the evidence for DCC during immediate resuscitation is less clear.

The transition to extra-uterine life is a complex physiological process comprising several different mechanisms that must happen simultaneously.

In optimal circumstances, spontaneous breathing aerates the lung and leads to a fall in pulmonary vascular resistance and subsequent increased pulmonary blood flow.¹ This transition requires additional blood volume which is drawn from the low resistance placental circulation.² Immediate clamping of the cord interrupts this normal physiological process and can reduce venous return to the heart by 30-50%,³ subsequently reducing cardiac output which can lead to circulatory collapse in the preterm infant⁴. When cord clamping precedes aeration of the lungs this reduction in cardiac output could potentially result in reduced cerebral blood flow which has been shown to be associated with intraventricular haemorrhage (IVH)¹.

Delaying cord clamping has been shown to result in a 20-30% increase in blood volume.^5,6 A Cochrane review in 2012 demonstrated that DCC in preterm infants can lead to improved circulatory stability, less need for blood transfusion, reduced incidence of necrotising enterocolitis and a lower risk of IVH7. Delayed card clamping is now recommended by the major resuscitation councils^8-10.

Benefits of delayed cord clamping for preterm infant include:

• Reduced need for inotropic support (RR 42 (95%CI 0.23-0.77)⁷
• Reduced incidence of NEC (5 trials 241 infants, RR 62 95%CI 0.43-0.90)⁷
• Less need for blood transfusion (7 trials, 392 infants: RR 61 95% CI 0.46–0.81)⁷

A recent meta-analysis including 18 trials with 2834 infants demonstrated a significant reduction in mortality (RR0.68 95%CI 0.52-0.90, NNT33)¹¹. This analysis was heavily weighted on one study were the adherence to DCC was 73.2%. The majority of these infants received Immediate Cord Clamping (ICC) due to clinical concerns of the infant. It did not demonstrate any reduction in IVH or NEC as shown by previous reviews¹².

Risks of delayed cord clamping for preterm infant include:

• higher peak bilirubin level in infants receiving DCC (7 trials 320 infants;  approx. difference 15mmol/L 95%CI 5.62-40)⁷

Benefits of delayed cord clamping for term baby include:

• higher birth weight (12 trials, 3139 infants mean difference 118g 95%CI 45-157)¹³
• Higher haemoglobin concentration (mean difference 2.17g/dl 95%CI 06-0.28)¹³
• Lower incidence of iron deficiency (RR65 95%CI 1.04–6.73)¹³
• Improved fine-motor and social domains at 4 years of age¹³

Risks of delayed cord clamping for term baby include:

• The infants receiving DCC required more phototherapy (97 trials 2324 infants, 2.47% vs 36% 0.62 95%CI 0.41–0.96)¹³

All babies will be eligible for delayed cord clamping unless there is:

• A requirement for immediate resuscitation.
• Cord issues i.e. no pulsation, cord snapping or incision, limited cord length.
• Placental abruption or early separation.
• Uterine inversion.
• Monochorionic twins (where risk of placental vessel anastomoses may result in draining of blood from twin 2 to twin 1 during DCC procedure).
• Maternal concern e.g. PPH, shock, seizure etc.

1. Following a vaginal birth:

• The baby is delivered and routine drying and stimulation takes place.
• The baby can go into skin-to-skin contact within the constraints of the length of umbilical cord.
• Clamping and cutting of the umbilical cord is delayed to allow placental transfusion¹⁴, unless mother or baby requires resuscitation, according to the agreed management plan for the 3rd stage of labour (i.e. physiological or active management). With physiological management there is no routine use of uterotonic drugs, no clamping of the cord until pulsation has stopped and the placenta is delivered by maternal effort. With active management a uterotonic drug is given and the cord is clamped by 5 minutes in order that controlled cord traction can be undertaken following signs of placental separation.¹⁵

2. Following a caesarean section delivery:

• The baby should be held below the level of the incision site, and definitely no more than 10cm above the uterus.
• Consideration must be given to prevention of heat loss during the procedure i.e. a warm, sterile towel placed over the baby throughout.
• There should be a delay of at least 1 minute before clamping of the cord, unless the cord pulsation ceases or the infant requires immediate resuscitation, or if there are maternal concerns.

1. Straňák Z, Feyereislová S, Korček P, Dempsey E. Placental transfusion and cardiovascular instability in the preterm infant. Frontiers in Pediatrics 2018 6:39 Free full text
2. Dawes, S. Foetal and Neonatal Physiology: A comparative study of the changes at birth. Chicago: Year Book Medical Publishers Inc 1968
3. Bhatt S, Alison B, Wallace E, Crossley K, Gill A, Kluckow M et al. Delaying cord clamping untilventilation onset improves cardiovascular function at birth in preterm lambs. The Journal of Physiology 2013 591(8):2113-2126 Free full text
4. Mercer, J; Vohr, B; McGrath, M; Padbury, J; Wallach, M & Oh, W. Delayed cord clampingin very premature infants reduces the incidence of IVH and late onset sepsis: A randomised control trial. Paediatrics 2006 117(4):1235-1242 Free full text
5. Yao A, Lind Effect of Gravity on placental transfusion. The Lancet 1969 294(7619):505-508 DOI: 10.1016/S0140-6736(69)90213-X link
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7. Rabe H, Diaz-Rossello J, Duley L, Dowswell T. Effect of timing of umbilical cord clamping andother strategies to influence placental transfusion at preterm birth on maternal and infant outcomes. Cochrane Database of Systematic Reviews 2012 Issue 8. Art. No.: CD003248 Free full text
8. Wyckoff M, Aziz K, Escobedo M, Kapadia V, Kattwinkel J, Perlman J et al. Part 13: Neonatal resuscitation. 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation 2015 132(18 suppl 2):S543-S560 Free full text
9. Wyllie J, Bruinenberg J, Roehr CC. European Resuscitation Council Guidelines for Resuscitation 2015: Section 7. Resuscitation and support of transition of babies at birth. Resuscitation 2015 95(Oct):249–263 Free full text
10. Perlman JM, Wyllie J, Kattwinkel J. Neonatal Resuscitation Chapter Collaborato Part 7: Neonatal resuscitation: 2015 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations (reprint). Pediatrics 2015 136(suppl 2):S120–166 Free full text
11. Fogarty M, Osborn D, Askie L, Seidler A, Hunter K, Lui K et al. Delayed vs early umbilical cordclamping for preterm infants: a systematic review and meta-analysis. American Journal of Obstetrics and Gynecology 2018 218(1):1-18 Available from: https://www.clinicalkey.com/#!/content/journal/1-s2.0-S0002937817314394
12. Tarnow-Mordi, MB. Delayed versus Immediate cord clamping in preterm infants. NEJM 2017 377:2445-2455 DOI: 10.1097/01.ogx.0000534708.24689.e0
13. McDonald S, Middleton P, Dowswell T, Morris PS  Effect of timing of umbilical cordclamping on term infants on maternal and neonatal outcomes (Review). Cochrane Database Systematic Review 2013 Issue 7. Art. No.: CD004074Free full text
14. Yao A, Hirvensalo M, Lind J (1968) Placental transfusion rate and uterine contraction. The Lancet 1968 291(7539):380-383 DOI: 10.1016/S0140-6736(68)91352-4
15. National Institute for Health and Care Excellence. Intrapartum care for healthy women and babies. Clinical guideline 190 (CG190) 2014, last updated 2017 Free full text