Wait a minute? An observational cohort study comparing iron stores in healthy Swedish infants at 4 months of age after 10-, 60- and 180-second umbilical cord clamping

BMJ Open. 2017 Dec 29;7(12):e017215. doi: 10.1136/bmjopen-2017-017215.


Background and objective: Umbilical cord blood (UCB) is a valuable stem cell source used for transplantation. Immediate umbilical cord (UC) clamping is widely practised, but delayed UC clamping is increasingly advocated to reduce possible infant anaemia. The aim of this study was to investigate an intermediate UC clamping time point and to evaluate iron status at the age of 4 months in infants who had the UC clamped after 60 s and compare the results with immediate and late UC clamping.

Design: Prospective observational study with two historical controls.

Setting: A university hospital in Stockholm, Sweden, and a county hospital in Halland, Sweden.

Methods: Iron status was assessed at 4 months in 200 prospectively recruited term infants whose UC was clamped 60 s after birth. The newborn baby was held below the uterine level for the first 30 s before placing the infant on the mother's abdomen for additional 30 s. The results were compared with data from a previously conducted randomised controlled trial including infants subjected to UC clamping at ≤10 s (n=200) or ≥180 s (n=200) after delivery.

Results: After adjustment for age differences at the time of follow-up, serum ferritin concentrations were 77, 103 and 114 µg/L in the 10, 60 and 180 s groups, respectively. The adjusted ferritin concentration was significantly higher in the 60 s group compared with the 10 s group (P=0.002), while the difference between the 60 and 180 s groups was not significant (P=0.29).

Conclusion: In this study of healthy term infants, 60 s UC clamping with 30 s lowering of the baby below the uterine level resulted in higher serum ferritin concentrations at 4 months compared with 10 s UC clamping. The results suggest that delaying the UC clamping for 60 s reduces the risk for iron deficiency.

Trial registration number: NCT01245296.

Keywords: fetal medicine; iron deficiency; paediatrics; umbilical cord clamping.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anemia, Iron-Deficiency / blood
  • Anemia, Iron-Deficiency / prevention & control*
  • Constriction*
  • Delivery, Obstetric*
  • Female
  • Ferritins / blood
  • Fetal Blood / metabolism*
  • Humans
  • Infant
  • Infant Health*
  • Infant, Newborn
  • Iron / blood*
  • Iron Deficiencies
  • Male
  • Parturition
  • Postpartum Period
  • Pregnancy
  • Prospective Studies
  • Stem Cells
  • Sweden
  • Time Factors
  • Tissue and Organ Harvesting
  • Umbilical Cord / blood supply*


  • Ferritins
  • Iron

Associated data

  • ClinicalTrials.gov/NCT01245296