title: Effect of Delayed Cord Clamping on Systemic Blood Flow: A Randomized Controlled Trial.
abstract: OBJECTIVE
  To determine whether delayed cord clamping improves systemic blood flow compared with immediate cord clamping in very preterm infants in the first 24 hours.
  
  
  METHODS
  Women delivering at <30 weeks' gestation at 5 tertiary centers were randomized to receive immediate cord clamping (<10 seconds) or delayed cord clamping (≥60 seconds). Echocardiography and cardiorespiratory data were collected at 3, 9, and 24 hours after birth. The primary outcome was mean lowest superior vena cava (SVC) flow.
  
  
  RESULTS
  Of 266 infants enrolled, 133 were randomized to immediate cord clamping and 133 to delayed cord clamping. The 2 groups were similar at baseline, including mean gestation (immediate cord clamping 28 weeks vs delayed cord clamping 28 weeks) and birth weight (immediate cord clamping 1003 g vs delayed cord clamping 1044 g). There was no significant difference between groups in the primary outcome of mean lowest SVC flow (immediate cord clamping 71.4 mL/kg/min [SD 28.1] vs delayed cord clamping 70.2 mL/kg/min [SD 26.9]; P = .7). For secondary outcomes, hemoglobin increased by 0.9 g/dL at 6 hours in the group with delayed cord clamping (95% CI 3.9, 14.4; P = .0005, adjusted for baseline). The group with delayed cord clamping had lower right ventricular output (-21.9 mL/kg/min, 95% CI -39.0, -4.7; P = .01). Rates of treated hypotension, ductus arteriosus size and shunt direction, and treatment of the ductus arteriosus were similar.
  
  
  CONCLUSIONS
  Delayed cord clamping had no effect on systemic blood flow measured as mean lowest SVC flow in the first 24 hours in infants <30 weeks' gestation.
  
  
  BACKGROUND
  Australia New Zealand Clinical Trials Registry: ACTRN12610000633088.
authors: Department of Neonatology, Children's Hospital at Westmead, New South Wales, Australia; University of Sydney, Sydney, New South Wales, Australia.
authors: Himanshu
authors: H
authors: Popat
authors: University of Sydney, Sydney, New South Wales, Australia; NHMRC Clinical Trials Centre, University of Sydney, Camperdown, New South Wales, Australia.
authors: Kristy P
authors: KP
authors: Robledo
authors: University of Sydney, Sydney, New South Wales, Australia; NHMRC Clinical Trials Centre, University of Sydney, Camperdown, New South Wales, Australia.
authors: Lucille
authors: L
authors: Sebastian
authors: University of Sydney, Sydney, New South Wales, Australia; Department of Neonatology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
authors: Nicholas
authors: N
authors: Evans
authors: Centre for Neonatal Education and Research, University of Western Australia, Western Australia, Australia.
authors: Andrew
authors: A
authors: Gill
authors: University of Sydney, Sydney, New South Wales, Australia; Department of Neonatology, Royal North Shore Hospital, St Leonards, New South Wales, Australia.
authors: Martin
authors: M
authors: Kluckow
authors: Department of Neonatology, Flinders Medical Centre, Bedford Park, South Australia, Australia.
authors: Sanjay
authors: S
authors: Sinhal
authors: Department of Neonatology, John Hunter Children's Hospital, New Lambton, New South Wales, Australia.
authors: Koert
authors: K
authors: de Waal
authors: University of Sydney, Sydney, New South Wales, Australia; NHMRC Clinical Trials Centre, University of Sydney, Camperdown, New South Wales, Australia.
authors: William
authors: W
authors: Tarnow-Mordi
authors: University of Sydney, Sydney, New South Wales, Australia; Department of Neonatology, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia. Electronic address: david.osborn@sydney.edu.au.
authors: David
authors: D
authors: Osborn
mesh_terms: D001315:Australia; D001783:Blood Flow Velocity; D003250:Constriction; D004452:Echocardiography; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood / Q000502:physiology*; D009520:New Zealand; D013997:Time Factors; D014470:Umbilical Cord / Q000601:surgery*; D014683:Vena Cava, Superior / Q000502:physiology*
keywords: cardiac output; hemodynamics; premature infant