Delayed clamping vs milking of umbilical cord in preterm infants: a randomized controlled trial

Published:February 17, 2019DOI:


      It has been established that delayed umbilical cord clamping in preterm infants results in improvement in neonatal anemia, need for transfusion, incidence of necrotizing enterocolitis, and intraventricular hemorrhage by increasing neonatal circulating blood volume. However, the effects of umbilical cord milking as an alternative to delayed clamping in preterm infants are unclear.


      The primary objective of this study was to compare the effect of delayed clamping vs milking of the umbilical cord on the initial hematocrit concentration in preterm births (23–34 weeks gestation). In addition, we sought to compare the effects of delayed clamping vs milking on the incidences of intraventricular hemorrhage, necrotizing enterocolitis, and need for transfusion (secondary objectives).

      Study Design

      The study was an unblinded randomized controlled trial of singleton preterm infants who were born 23 weeks 0 days to 34 weeks 6 days gestation and were assigned to 1 of 2 controlled study groups: delayed cord clamping for 60 seconds or milking of the cord towards the infant 4 times before clamping. Randomization occurred via block randomization with an allocation ratio of 1 to 1. The patients’ third stage of delivery was standardized for route of delivery and randomization arm. All comparisons were preformed with an intent-to-treat analysis approach. The study was powered at 80% with a probability value of .05 for the primary outcome measure of a hematocrit difference of 3% between the 2 groups.


      Of the 204 randomized patients, 104 were assigned to the delayed subgroup, and 100 were assigned to the milking subgroup. There were no significant differences in baseline maternal characteristics noted between groups. Though there was not any statistically significant difference in neonatal outcomes between the cord clamping and milking groups, the occurrences of transfusion (15.5% vs 9.1%; P=.24), necrotizing enterocolitis (5.8% vs 3.0%; P=.49), and intraventricular hemorrhage (15.5% vs 10.1%; P=.35) were all lower in the milking group. The milking group had higher initial hematocrit concentration compared with the delayed clamping group, although this was not significant (51.8 [6.2%] vs 49.9 [7.7%]; P=.07]. Peak bilirubin levels and need for phototherapy were similar between groups.


      This study demonstrates that milking the umbilical cord may be an acceptable alternative to delayed cord clamping because there were similar effects on neonatal hematocrit concentrations and the need for neonatal transfusions and no increased risk for complications or neonatal morbidity. The present data support the concept that milking of the umbilical cord may offer an efficient and timely method of providing increased blood volume to the infant.

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        • Committee on Obstetric Practice ACoO, Gynecologists
        Committee Opinion No. 543: timing of umbilical cord clamping after birth.
        Obstet Gynecol. 2012; 120: 1522-1526
      1. American College of Nurse Midwives. Delayed Umbilical Cord Clamping: Position Statement. Available at: Published May 2014. Approved May 2014. Accessed August 1, 2018.

        • Rabe H.
        • Diaz-Rossello J.L.
        • Duley L.
        • Dowswell T.
        Effect of timing of umbilical cord clamping and other strategies to influence placental transfusion at preterm birth on maternal and infant outcomes.
        Cochrane Database Syst Rev. 2012; 8: CD003248
        • Rabe H.
        • Reynolds G.
        • Diaz-Rossello J.
        A systematic review and meta-analysis of a brief delay in clamping the umbilical cord of preterm infants.
        Neonatology. 2008; 93: 138-144
        • McDonald S.J.
        • Middleton P.
        • Dowswell T.
        • Morris P.S.
        Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes.
        Cochrane Database Syst Rev. 2013; 7: CD004074
        • Pisacane A.
        Neonatal prevention of iron deficiency.
        BMJ. 1996; 312: 136-137
        • Kumar B.
        • Upadhyay A.
        • Gothwal S.
        • Jaiswal V.
        • Joshi P.
        • Dubey K.
        Umbilical cord milking and hematological parameters in moderate to late preterm neonates: a randomized controlled trial.
        Indian Pediatr. 2015; 52: 753-757
        • Upadhyay A.
        • Gothwal S.
        • Parihar R.
        • et al.
        Effect of umbilical cord milking in term and near term infants: randomized control trial.
        Am J Obstet Gynecol. 2013; 208: 120.e1-120.e6
        • Al-Wassia H.
        • Shah P.S.
        Efficacy and safety of umbilical cord milking at birth: a systematic review and meta-analysis.
        JAMA Pediatr. 2015; 169: 18-25
        • Fogarty M.
        • Osborn D.A.
        • Askie L.
        • et al.
        Delayed vs early umbilical cord clamping for preterm infants: a systematic review and meta-analysis.
        Am J Obstet Gynecol. 2018; 218: 1-18
        • Backes C.H.
        • Rivera B.K.
        • Haque U.
        • et al.
        Placental transfusion strategies in very preterm neonates: a systematic review and meta-analysis.
        Obstet Gynecol. 2014; 124: 47-56
        • Katheria A.C.
        • Truong G.
        • Cousins L.
        • Oshiro B.
        • Finer N.N.
        Umbilical cord milking versus delayed cord clamping in preterm infants.
        Pediatrics. 2015; 136: 61-69
        • Rabe H.
        • Jewison A.
        • Alvarez R.F.
        • et al.
        Milking compared with delayed cord clamping to increase placental transfusion in preterm neonates: a randomized controlled trial.
        Obstet Gynecol. 2011; 117: 205-211
        • Tarnow-Mordi W.
        • Morris J.
        • Kirby A.
        • et al.
        Delayed versus immediate cord clamping in preterm infants.
        N Engl J Med. 2017; 377: 2445-2455
        • Schulz K.F.
        • Altman D.G.
        • Moher D.
        CONSORT 2010 statement: updated guidelines for reporting parallel group randomised trials.
        BMJ. 2010; 340: c332
        • Macones G.A.
        • Hankins G.D.
        • Spong C.Y.
        • Hauth J.
        • Moore T.
        The 2008 National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines.
        Obstet Gynecol. 2008; 112: 661-666
        • Hosono S.
        • Mugishima H.
        • Fujita H.
        • et al.
        Umbilical cord milking reduces the need for red cell transfusions and improves neonatal adaptation in infants born at less than 29 weeks’ gestation: a randomised controlled trial.
        Arch Dis Child Fetal Neonatal Ed. 2008; 93: F14-F19
        • Kaempf J.W.
        • Tomlinson M.W.
        • Kaempf A.J.
        • et al.
        Delayed umbilical cord clamping in premature neonates.
        Obstet Gynecol. 2012; 120: 325-330
        • McCausland A.M.
        • Holmes F.
        • Schumann W.R.
        Management of cord and placental blood and its effect upon the newborn.
        Calif Med. 1949; 71 (190-19)
        • March M.I.
        • Hacker M.R.
        • Parson A.W.
        • Modest A.M.
        • de Veciana M.
        The effects of umbilical cord milking in extremely preterm infants: a randomized controlled trial.
        J Perinatol. 2013; 33: 763-767
        • Patel S.
        • Clark E.A.
        • Rodriguez C.E.
        • Metz T.D.
        • Abbaszadeh M.
        • Yoder B.A.
        Effect of umbilical cord milking on morbidity and survival in extremely low gestational age neonates.
        Am J Obstet Gynecol. 2014; 211: 519.e1-519.e7