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Effect of delayed versus early umbilical cord clamping on neonatal outcomes and iron status at 4 months: a randomised controlled trial

BMJ 2011; 343 doi: (Published 15 November 2011) Cite this as: BMJ 2011;343:d7157
  1. Ola Andersson, consultant in neonatology12,
  2. Lena Hellström-Westas, professor of perinatal medicine2,
  3. Dan Andersson, head of departments of paediatrics, obstetrics and gynaecology1,
  4. Magnus Domellöf, associate professor, head of paediatrics3
  1. 1Department of Paediatrics, Hospital of Halland, Halmstad, SE-301 85 Halmstad, Sweden
  2. 2Department of Women’s and Children’s Health, Uppsala University, SE-751 85 Uppsala, Sweden
  3. 3Department of Clinical Sciences, Paediatrics, Umeå University, SE-901 85 Umeå, Sweden
  1. Correspondence to: O Andersson ola.k.andersson{at}
  • Accepted 29 September 2011


Objective To investigate the effects of delayed umbilical cord clamping, compared with early clamping, on infant iron status at 4 months of age in a European setting.

Design Randomised controlled trial.

Setting Swedish county hospital.

Participants 400 full term infants born after a low risk pregnancy.

Intervention Infants were randomised to delayed umbilical cord clamping (≥180 seconds after delivery) or early clamping (≤10 seconds after delivery).

Main outcome measures Haemoglobin and iron status at 4 months of age with the power estimate based on serum ferritin levels. Secondary outcomes included neonatal anaemia, early respiratory symptoms, polycythaemia, and need for phototherapy.

Results At 4 months of age, infants showed no significant differences in haemoglobin concentration between the groups, but infants subjected to delayed cord clamping had 45% (95% confidence interval 23% to 71%) higher mean ferritin concentration (117 μg/L v 81 μg/L, P<0.001) and a lower prevalence of iron deficiency (1 (0.6%) v 10 (5.7%), P=0.01, relative risk reduction 0.90; number needed to treat=20 (17 to 67)). As for secondary outcomes, the delayed cord clamping group had lower prevalence of neonatal anaemia at 2 days of age (2 (1.2%) v 10 (6.3%), P=0.02, relative risk reduction 0.80, number needed to treat 20 (15 to 111)). There were no significant differences between groups in postnatal respiratory symptoms, polycythaemia, or hyperbilirubinaemia requiring phototherapy.

Conclusions Delayed cord clamping, compared with early clamping, resulted in improved iron status and reduced prevalence of iron deficiency at 4 months of age, and reduced prevalence of neonatal anaemia, without demonstrable adverse effects. As iron deficiency in infants even without anaemia has been associated with impaired development, delayed cord clamping seems to benefit full term infants even in regions with a relatively low prevalence of iron deficiency anaemia.

Trial registration Clinical Trials NCT01245296.


  • We thank Josefin Roswall and research nurses Eivor Kjellberg and Monika Nygren at the Department of Paediatrics, the staff at the Department of Obstetrics and Gynaecology, and all mothers and infants who participated in the study. We thank Associate Professor Amir Baigi and Professor Ulf Strömberg for valuable statistical advice.

  • Contributors: OA helped design the study; was responsible for staff training, study management, and data collection; and took part in data analysis and manuscript writing. LH-W helped design the study; advised on staff training, study management, and data collection; and took part in data analysis and manuscript writing. DA helped design the study; advised on staff training, study management, and data collection and analysis; and took part in manuscript writing. MD helped design the study; advised on staff training, study management, and data collection; and took part in data analysis and manuscript writing. OA and MD are guarantors for the study.

  • Funding: This study was supported by grants from the Regional Scientific Council of Halland; the HASNA Foundation, Halmstad; HRH Crown Princess Lovisa’s Foundation for Child Care, Stockholm; and the Framework of Positive Scientific Culture, Hospital of Halland, Halmstad. The funders were not involved in the study design, data analysis, or manuscript preparation.

  • Competing interests: All authors have completed the ICMJE uniform disclosure form at (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

  • Ethical approval: The study was approved by the regional research ethics committee at Lund University (41/2008). Written informed consent was obtained by a midwife before the intervention.

  • Data sharing: No additional data available.

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