Delayed Clamping of the Umbilical Cord: A Review with Implications for Practice

Gina Eichenbaum-Pikser, CNM, MSN; Joanna S. Zasloff, CNM, MSN


J Midwifery Womens Health. 2009;5(4):321-326. 

In This Article

Potential Adverse Effects of Delayed Cord Clamping

It has been postulated that delayed cord clamping may increase rates of hyperbilirubinemia, polycythemia, and transient tachypnea in the newborn or maternal hemorrhage. However, delayed cord clamping has never been proven to increase the rate of neonatal symptomatic disease or maternal blood loss.[3,6,9]


Polycythemia is defined as a Hct level > 65% and occurs in about 2% to 5% of term newborns.[11] The primary concern with polycythemia is related to the development of blood hyperviscosity. The need for treatment of polycythemia is determined by elevated Hct levels along with the presence of symptoms. A partial exchange transfusion is used to treat newborns with a Hct over institutionally prescribed levels, which is usually = 65%.[11]

Data on the risks of developing polycythemia from delayed cord clamping are varied. In the metaanalysis by Hutton and Hassan,[2] the risk of developing polycythemia was slightly higher in neonates allocated to delayed cord clamping at both 7 hours after birth (RR, 3.44; 95% CI, 1.25–9.52; two trials; n = 236) and at 24 to 48 hours after birth (RR, 3.82; 95% CI, 1.11–13.21; 7 trials; n = 403). Most significant was the finding that none of the polycythemic infants were symptomatic or needed treatment. In a double blind RCT of 64 full-term infants, Jahazi et al.[5] found that no infant developed clinical manifestations of polycythemia at 2 hours, 18 hours, or 5 days after birth, but that 21.9% of the infants from both delayed and immediate clamping developed asymptomatic polycythemia at 2 hours of life. There were no significant differences between the two groups. McDonald and Middleton's[3] Cochrane metaanalysis found that there was no significant difference or increased risk for developing polycythemia when delayed cord clamping was performed (RR, 0.39; 95% CI, 0.12–1.27; n = 463).


The potential for developing hyperbilirubinemia is another issue of concern. In their systematic review, using data from 1009 infants, Hutton and Hassan[2] found no significant difference in mean serum bilirubin levels nor an increased risk of neonatal jaundice within the first 24 hours of life associated with late clamping (RR, 1.35; 95% CI, 1.00–1.81). One of their included studies reported a mean bilirubin level of 192.8 mmol/L in the late clamping group versus 175.7 mmol/L in the early clamping group. Another trial found a mean bilirubin of 99.18 mmol/L in the late clamping group and 104.31 mmol/L in the early clamping group.[2] They also report no significant difference between the groups in risk of jaundice at 3 to 14 days after birth nor in the percentage of infants with bilirubin levels exceeding 256.5 mmol/L (15 g/dL) requiring phototherapy (RR, 1.27; 95% CI, 0.76–2.10; 1 trial; n = 332).[2] Furthermore, using 3 RCTs (n = 111), Rabe et al. found that none of the neonates with elevated bilirubin levels required phototherapy treatment or exchange transfusions.[6]

McDonald and Middleton's[3] Cochrane metaanalysis found that the difference between early and late cord clamping for clinical jaundice did not reach statistical significance (RR, 0.83; 95% CI, 0.65–1.06; n = 1828). However, significantly fewer infants in the early cord clamping group required phototherapy for jaundice than in the late clamping group (RR, 0.59; 95% CI, 0.38–0.92; n = 1762). They report that 3% of infants in the early group and 5% of infants in the late group required therapy, a risk difference of 2%.[3]

Respiratory Distress

Transient tachypnea of the newborn may occur as a result of delayed absorption of lung fluid caused by an increase in blood volume related to delayed cord clamping. Although Cernadas et al.[9] found a slight increase in respiratory rate in those infants who experienced delayed cord clamping, no additional respiratory therapy was needed for these infants. McDonald and Middleton[3] found that both the delayed and immediate clamping groups had a similar number of infants admitted to any level of neonatal intensive care unit for respiratory distress (RR, 1.01; 95% CI, 0.18–5.75; n = 1008). Overall, the data concerning the relationship between respiratory distress and delayed cord clamping are inconclusive.

Maternal Hemorrhage

Immediate cord clamping is often included as part of active management of the third stage of labor. Although it is now well known that active management decreases the risk of postpartum hemorrhage, immediate cord clamping is not formally a component of active management and does not appear to aid in this risk reduction. McDonald and Middleton's[3] Cochrane review found no significant difference between early and late cord clamping groups with regard to = 500 mL blood loss (RR, 1.22; 95% CI, 0.96–1.55; n = 1878), mean maternal blood loss (WMD, 6.36 mL; 95% CI, -34.94–47.66; n = 963), maternal Hgb values at 24 to 72 hours after birth (WMD, -0.12 g/dL; 95% CI, -0.30–0.06; n = 1128), maternal need for blood transfusion (RR, 0.79; 95% CI, 0.20–3.15; n = 963), need for manual removal of the placenta (RR, 1.59; 95% CI, 0.78–3.26; n = 1515), instances of the third stage of labor lasting longer than 30 or 60 minutes (n = 963), or the need for the therapeutic administration of uterotonics (RR, 0.94; 95% CI, 0.74–1.20; n = 963).

Newborn Position

It has been suggested that the position of the newborn in relation to the placenta influences the amount of blood transfused. Van Rheenen et al.[7] and Van Rheenen and Brabin[8] recommend keeping the newborn between 10 cm above and 10 cm below the level of the placenta allowing for optimal transfusion within 3 minutes, while holding the newborn 40 cm below the placenta will shorten this time to1 minute. Levy and Blickstein[10] note that the infant may be placed at or below the level of the placenta to allow gravity to transfuse blood through the cord. Further research must be done on this topic in order to make a recommendation for the placement of the baby when delayed cord clamping is performed.


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