NCT03808051: ABC3

Aeration, Breathing, Clamping Study 3

Completed NA Last updated 25 November 2025

What this trial tests

NA trial testing Physiological-based cord clamping in Preterm Infant in 689 participants. Completed in 1 May 2025.

Timeline

25 January 2019

Primary endpoint
15 May 2023

1 May 2025

Quick facts

Lead sponsor	Leiden University Medical Center
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Enrollment	689
Start date	25 January 2019
Primary completion	15 May 2023
Estimated completion	1 May 2025
Sites	10 locations across Netherlands

Drugs / interventions tested

• Physiological-based cord clamping
• Time-based cord clamping

Conditions studied

• Preterm Infant — all drugs for Preterm Infant →
• Birth, Preterm — all drugs for Birth, Preterm →

Sponsor

Leiden University Medical Center

Who can join

Under 29 Weeks, any sex, with Preterm Infant or Birth, Preterm. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Delayed cord clamping (DCC) in preterm infants results in a decrease in mortality and a trend towards fewer intraventricular haemorrhages. However, preterm infants needing immediate interventions for stabilisation or resuscitation were generally clamped immediately and excluded from trials, while these infants might benefit the most of DCC.

Studies in preterm lambs demonstrated that delaying cord clamping beyond ventilation onset resulted in more stable hemodynamic transition. This approach was called 'physiological-based cord clamping' (PBCC). The hypothesis of this study is that PBCC in preterm infants at birth will lead to an increase in intact survival when compared to standard care.

This study is a multicentre randomised controlled, parallel design, superiority trial, including preterm infants less than 30 weeks of gestation. The intervention is PBCC: stabilisation of the infant with the umbilical cord intact and only clamp the cord when the infant is stable. Stable is defined as the establishment of heart rate greater than 100 bpm and oxygen saturation above 85% while using supplemental oxygen lower than 40%. In the control group cord clamping will be performed time-based: infants are clamped first (at 30-60 seconds if the clinical condition allows) and then moved to the resuscitation table for further stabilisation.

The primary outcome will be intact survival at NICU discharge, defined as survival without cerebral injury (intraventricular haemorrhage ≥ grade 2 and/or periventricular leukomalacia ≥ grade 2 and/or periventricular venous infarction) and/or necrotizing enterocolitis (Bell stage ≥ 2).

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. A review of different resuscitation platforms during delayed cord clamping.
   Katheria A, Lee HC, Knol R, Irvine L, et al · · 2021 · cited 24× · PMID 33850283 · DOI 10.1038/s41372-021-01052-3
2. Physiological versus time based cord clamping in very preterm infants (ABC3): a parallel-group, multicentre, randomised, controlled superiority trial.
   Knol R, Brouwer E, van den Akker T, DeKoninck PLJ, et al · · 2025 · cited 17× · PMID 39717227 · DOI 10.1016/j.lanepe.2024.101146
3. Physiological-based cord clamping in very preterm infants: the Aeration, Breathing, Clamping 3 (ABC3) trial-study protocol for a multicentre randomised controlled trial.
   Knol R, Brouwer E, van den Akker T, DeKoninck PLJ, et al · · 2022 · cited 16× · PMID 36183143 · DOI 10.1186/s13063-022-06789-6
4. Umbilical cord milking-benefits and risks.
   Koo J, Kilicdag H, Katheria A. · · 2023 · cited 13× · PMID 37144151 · DOI 10.3389/fped.2023.1146057
5. Neonatal Resuscitation with an Intact Cord: Current and Ongoing Trials.
   Katheria AC. · · 2019 · cited 13× · PMID 31013574 · DOI 10.3390/children6040060
6. Physiological-based cord clamping in very preterm infants: the Aeration, Breathing, Clamping 3 (ABC3) trial-statistical analysis plan for a multicenter randomized controlled trial.
   Willemsen SP, Knol R, Brouwer E, van den Akker T, et al · · 2024 · cited 4× · PMID 38439024 · DOI 10.1186/s13063-024-08014-y
7. How long is too long? No added benefit with prolonged ventilation with intact cord in preterm infants.
   Katheria A, Lakshminrusimha S. · · 2024 · cited 3× · PMID 38602842 · DOI 10.1113/jp286492
8. Optimizing transition: Providing oxygen during intact cord resuscitation.
   Edwards H, Dorner RA, Katheria AC. · · 2023 · cited 1× · PMID 37380527 · DOI 10.1016/j.semperi.2023.151787