The birth of a very preterm infant presents critical challenges, particularly in ensuring a smooth cardiovascular transition and optimizing placental transfusion. One proposed approach to improve outcomes is Physiological-Based Cord Clamping (PBCC), which aims to stabilize newborns before cutting the umbilical cord. The Aeration, Breathing, Clamping (ABC3) trial investigated whether PBCC improves intact survival compared to Time-Based Delayed Cord Clamping (TBCC) in infants born before 30 weeks of gestation.
The ABC3 trial was a multicentre, randomized, controlled superiority clinical trial conducted in all Dutch tertiary referral centres for perinatal care. The study involved 669 preterm infants and aimed to assess whether PBCC improves survival without major cerebral injury or necrotizing enterocolitis.
Methodology
Infants were randomized into two groups: PBCC or TBCC.
PBCC: The umbilical cord remained intact while the infant was stabilized. Clamping occurred only after achieving a heart rate above 100 bpm and oxygen saturation above 85% with supplemental oxygen below 40%.
TBCC: The umbilical cord was clamped between 30–60 seconds after birth.
The primary outcome measured was survival without major cerebral injury or necrotizing enterocolitis.
Key Findings
The study found no significant difference in intact survival between the two groups:
PBCC Group: 71.1% survival. TBCC Group: 67.6% survival. Odds Ratio: 1.18 (95% CI 0.84–1.66, p = 0.33)
However, pre-specified subgroup analysis revealed an intriguing result:
Male infants had a higher survival rate with PBCC (69.9%) compared to TBCC (61.8%). Odds Ratio: 2.32 (95% CI 1.42–3.78, p for interaction 0.026)
This suggests a potential gender-specific benefit, though further research is needed.
Secondary Outcomes
Beyond survival rates, the trial highlighted several benefits of PBCC:
- Fewer red blood cell transfusions (Rate ratio 0.83, p = 0.0003)
- Lower incidence of late-onset sepsis (27.4% vs. 33.3%, Odds ratio 0.77, p = 0.013)
- Lower admission temperature (36.3°C vs. 36.7°C, p < 0.0001)
- Improved parental experience
- Lower anxiety levels (Likert scale 1.52 vs. 2.23, p < 0.001)
- Higher contentment (Likert scale 4.74 vs. 4.49, p < 0.001)
- Conclusions and Future Implications
While PBCC did not significantly increase intact survival across the entire cohort, the potential benefit for male infants warrants further investigation. Moreover, PBCC was found to be safe to perform, with additional benefits such as fewer transfusions, reduced sepsis rates, and improved parental well-being.
What This Means for Neonatal Care
The ABC3 trial contributes valuable insights into neonatal care practices. As researchers continue to explore optimal cord clamping strategies, the findings emphasize the importance of personalized approaches in preterm infant care. Future studies may refine PBCC protocols to enhance outcomes further.
SurePulse
These research findings are of particular interest to SurePulse who’s vision is to give clinicians and healthcare providers the tools to provide optimal newborn care. The SurePulse VS Cap comprises an optical sensor integrated into a thermo-protective single-use cap which has been designed to provide clinical teams with accurate, reliable, and timely information in the critical moments after birth. The latest ILCOR guidelines recommend the use of a cap to prevent hypothermia after birth. SurePulse VS’ wireless approach means that baby’s heart rate can be monitored straight after birth, supporting optimal care during stabilisation and, where necessary, resuscitation.
