Placental transfusion at birth: do we have all of the answers?

Many questions remain about both delayed cord clamping (DCC) andumbilical cordmilking (UCM). Al-Wassia andShah1 report the firstmeta-analysisofUCMin infants.Wereviewcurrent recommendations and concerns impeding their translation into widespread practice. We next review new meta-analyses in the literature that address someof the remaining knowledge gaps for placental transfusion, including the aforementionedUCMmeta-analysis. Finally,wehighlight some remaining reasons clinicians should proceed cautiously in adopting these practices. In December 2012, the American College of Obstetricians and Gynecologists (ACOG) in association with the American Academy of Pediatrics released a statement titled “Timing of Umbilical Cord Clamping After Birth.”2 This statement concludes for preterm infants, “Evidence exists to support delayed umbilical cord clamping in preterm infants, when feasible. The single most important clinical benefit for preterm infants is the possibility for a nearly 50% reduction in intraventricular hemorrhage.”2 For term infants, they state, “currently, evidence is insufficient to confirmor refute the potential for benefits fromdelayedumbilical cord clamping in term infants, especially in settings with rich resources.”2 However, for both subgroups of infants theremay not yet beuniversalagreement.Forexample, in terminfants, theWorld HealthOrganization recommends the routinedelayofumbilical cord clamping by 1 to 3minutes after delivery of the baby. It also states that this is a particularly relevant intervention in underresourced settings where access to good nutrition and iron is limited during childhood.3 Furthermore, for preterm infants, despite this unequivocally optimistic statement, there appears to be reluctance to adopt thispractice.4,5Most recently, Jelinetal6 surveyedmembers ofACOGand theCollaborativeAmbulatoryResearchNetwork. Eighty-eightpercentof respondents indicated that their hospital did not have an umbilical cord clamping policy and 76% indicated that concern for delayed neonatal resuscitationwas a reason for immediate cord clamping. Although this survey was conducted prior to the 2012 ACOG statement, the underlyingevidencebase for this statementwasavailableprior to the administration of this survey. Anecdotally, neonatologists share the same concern for delayed resuscitation in the most preterm infants.7,8 Two approaches are reported in the literature to prevent delayed resuscitation. The first is the use of a mobile trolley to initiate resuscitation at themother’s bedside. Thomas et al9 presented pilot data on 78 babies with a median gestational age of 34weeks (range, 24-41weeks) resuscitated on amobile trolley. Although there were no adverse events and 77 of the 78 infants had a postresuscitation temperature higher than 36°C, on 18occasions theumbilical cordwas too short to reach the trolley. The randomized Cord Pilot Trial is evaluating this innovative tool and will provide further important data to consider.10Thesecondapproach isUCM,espoused in themodern era by Hosono et al.11 Umbilical cord milking is the act of cutting a long segment of the umbilical cord and stripping it toward the infant to provide placental transfusion more rapidly thanwithDCC. The hope is that UCMwill provide similar benefit while minimizing delay in resuscitation. Indeed, the effect of UCMas comparedwithDCCwas one of thegaps inknowledgehighlightedbyACOGinthe2012statement. The other 2 acknowledged gaps were (1) the ideal duration forumbilical cordclampingespeciallywith regard to cesarean vs vaginal delivery and (2) the need for additional evidence for infants born before 28 weeks’ gestation. While there is not yet additional information to address the questionof durationofDCC, additionalmeta-analyses have examined UCM or DCC strategies in our smallest patients. In considering the ACOG recommendations, the current meta-analysis by Al-Wassia and Shah is important. This is the first systematic review of evidence for UCM in both term and preterm infants. The analysis includes 7 randomized clinical trials, involving 501 infants, evaluating the impact ofUCM.Of these, 5 trials compared UCMwith immediate cord clamping and 2 compared UCMwith DCC.When analyzing the data for preterm infants (<33 weeks’ gestation) only, 5 studies of 277 infantswere included.Theauthors foundareducedriskofoxygen requirement at 36 weeks (risk ratio, 0.42 [95% CI, 0.210.83]) and intraventricular hemorrhage (IVH) overall (risk ratio, 0.62 [95%CI,0.41-0.93]).However, therewasnodifference in severe IVH (grades 3 and 4) or death prior to discharge. Although the initial hemoglobin level was greater in the UCM group (meandifference [MD], 2.0 [95%CI, 1.3-2.7] g/dL [to convert to gramsper liter,multiply by 10.0]), thenumber of blood transfusionswasnot reduced.Most importantly, neurodevelopmental outcomes were not reported. Of these trials, 2 provideddatapooled for 224 infantswith a gestational age of at least 33 weeks. In this subgroup, UCM resulted in higher hemoglobin values at 48 hours after birth (MD, 1.2 [95% CI, 0.8-1.5] g/dL; I2 = 34%). This was without greater peak bilirubin levels or need for phototherapy. In addition, a single study (n = 170) reported higher levels of hemoglobin (MD, 1.1 [95% CI, 0.7-1.5] g/dL) and ferritin (MD, 79 Related article page 18 Opinion