<scp>EBNEO</scp> Commentary on ‘Physiological Versus Time Based Cord Clamping in Very Preterm Infants (<scp>ABC3</scp>): A Parallel‐Group, Multicentre, Randomised, Controlled Superiority Trial’

Knol R, Brouwer E, van den Akker T, DeKoninck PLJ, Onland W, Vermeulen MJ, de Boode WP, van Kaam AH, Lopriore E, Reiss IKM, Hutten GJ, Prins SA, Mulder EEM, d'Haens EJ, Hulzebos CV, Bouma HA, van Sambeeck SJ, Niemarkt HJ, van der Putten ME, Lebon T, Zonnenberg IA, Nuytemans DH, Willemsen SP, Polglase GR, Steggerda SJ, Hooper SB, Te Pas AB. Physiological versus time based cord clamping in very preterm infants (ABC3): a parallel-group, multicentre, randomised, controlled superiority trial. Lancet Reg Health Eur. 2024 4; 48:101146. https://doi.org/10.1016/j.lanepe.2024.101146. PMID: 39717227; PMCID: PMC11664066. Intact cord resuscitation has been described since the early 14th century where the umbilical cord would not be clamped until the lungs were aerated [1]. Since then, observational cohort studies have suggested the benefit of maintaining placental circulation during initial breathing steps. Subsequently, randomised controlled trials comparing intact cord resuscitation to either immediate cord clamping or shorter durations of delayed cord clamping have been conducted. The ABC3 trial is the largest randomised controlled trial to date comparing intact cord resuscitation to a shorter unsupported time-based cord clamping approach. The ABC3 trial attempted to use a patient-centred approach to cord clamping whereby infants had their cord clamped once they reached a peripheral oxygen saturation of 85% while requiring less than 40% supplemental oxygen and had a heart rate of > 100 beats per minute. However, the minimum time was at least 3 min, and the maximum time was 10 min before cord clamping occurred. If there was excessive maternal blood loss, the cord was clamped earlier as well. The mean time of cord clamping was just under 6 min in the intervention group. In 2024, the International Liaison Committee on Resuscitation (ILCOR) published a consensus on Science with treamtent recommendations for preterm infants [2]. The current ILCOR recommendations are summarised here: ‘While it is reasonable to consider [deferral of cord clamping for 120 s or more (long DCC)], the task force cannot recommend the long deferral for all infants based on this evidence. Instead, the long deferral could be considered only if there is no contraindication and if appropriate newborn stabilization can be provided on the intact cord (skilled team, proper training, appropriate equipment, enough space and ability to provide thermal management). More evidence is needed before recommending long DCC. Practicality, feasibility, cost-effectiveness, and equity issues need to be addressed.’ The group of infants who had longer DCC and resuscitation initiated on the cord had lower average initial temperatures. It was noted that there was a positive impact of improved effect for outcomes based on the experience of the team in providing the intervention. As with other aspects of neonatal resuscitation that require coordination amongst team members, practice, experience, and training in behavioural skills are likely to advance care with newer approaches of cord management. In this study, the authors have studied the effect of long DCC and promoting lung aeration compared to shorter durations of DCC. While there were no statistically significant differences in their primary outcome, there were a number of secondary benefits such as fewer red blood cell transfusions and less late onset sepsis. In additional family centered outcomes such as less anxiety from parents was noted. The authors mention that infants in this study are being followed for long term outcomes. It will be interesting to see the impact of PBCC on the neurodevelopment of these infants who had improved haemoglobin and fewer blood transfusions. Andersson et al. demonstrated improved 4-year outcomes in term infants receiving 3 min of DCC compared to early cord clamping [3]. It is possible that preterm infants may have even greater benefits given their high risk of neurodevelopmental impairment. URL Link: https://ebneo.org/ebneo-commentary-physiological-versus-time-based-cord-clamping-in-very-preterm-infants-abc3/. The authors declare no conflicts of interest.