Delayed Clamping of the Umbilical Cord Study

Delayed clamping of the umbilical cord may affect health outcomes by allowing blood flow between the placenta, umbilical cord, and baby to continue.

In their recent study, Anna Lene Seidler, PhD and colleagues concluded that deferred cord clamping reduces death before discharge in preterm infants when compared with immediate cord clamping. This study is published in the Lancet.

Umbilical cord clamping strategies at preterm birth potentially affect essential health outcomes. This study compared the effectiveness of deferred and immediate cord clamping and umbilical cord milking at preterm birth in reducing neonatal mortality and morbidity.

Study Methodology

Researchers searched medical databases and RCTs comparing deferred and immediate cord clamping and cord milking for preterm births, excluding quasi-randomized or cluster-randomized trials. They invited authors of eligible studies to join the collaboration and share individual participant data. They checked data and assessed bias risk. Death before hospital discharge was the primary outcome measured. They performed intention-to-treat one-stage individual participant data meta-analyses accounting for heterogeneity to examine treatment effects overall and in prespecified subgroup analyses.

Study Summary

• Two thousand three hundred sixty-nine records were identified, and 48 randomised trials were eligible.
• They included individual participant data on 6367 infants (3303 male, 2667 female, two intersex, and 395 missing data).
• Unlike immediate cord clamping, deferred cord clamping reduced death before discharge with an odds ratio of 0.68.
• For umbilical cord milking compared with immediate cord clamping, no clear evidence was found of a difference in death before discharge with OR 0.73.
• For umbilical cord milking compared with deferred cord clamping, no clear evidence was found of a difference in death before discharge.
• They found no evidence of subgroup differences for the primary outcome, including gestational age, delivery type, multiple births, study year, and perinatal mortality.

Interpretation

Interpreting further, they said, "Our study provided high-certainty evidence that deferred cord clamping reduces death before discharge in preterm infants. This effect is consistent across several participant-level and trial-level subgroups."

They added that these results will inform international treatment recommendations.

Funding

Australian National Health and Medical Research Council funded the study.

Reference

Seidler et al. Deferred cord clamping, cord milking, and immediate cord clamping at preterm birth: a systematic review and individual participant data meta-analysis. The Lancet, 402(10418), 2209–2222.