Delayed cord clamping in preterm infants delivered at 34-36 weeks' gestation: a randomised controlled trial

Background: Even mild iron deficiency and anaemia in infancy may be associated with cognitive deficits. A delay in clamping the cord improves haematocrit levels and results in greater vascular stability and less need for packed cell transfusions for anaemia in the first period after birth. Follow-up data on haemoglobin levels after the neonatal period were not available. Objective: To provide neonatal and follow-up data for the effects of early or delayed clamping of the card. Methods: 37 premature infants (gestational age 34 weeks, 0 days-36 weeks, 6 days) were randomly assigned to one of two groups in the first hour after birth, and at 10 weeks of age. In one group the umbilical cord was clamped within 30 seconds (mean (SD) 13.4 (5.6)) and in the other, it was clamped at 3 minutes after delivery. In the neonatal period blood glucose and haemoglobin levels were determined. At 10 weeks of age haemoglobin and ferritin levels were determined. Results: The late cord-clamped group showed consistently higher haemoglobin levels than the early cord-clamped group, both at the age of 1 hour (mean (SD) 13.4 (1.9) mmol/l vs 11.1 (1.7) mmol/l), and at 10 weeks (6.7 (0.75) mmol/l vs 6.0 (0.65) mmol/l). No relationship between delayed clamping of the umbilical cord and pathological jaundice or polycythaemia was found. Conclusion: Immediate clamping of the umbilical cord should be discouraged.