Is immediate arterial cord blood sampling necessary in vigorous term neonates? A retrospective study of the impact of cord clamping timing on cord blood gas analysis.

OBJECTIVE

To evaluate whether immediate arterial cord blood sampling is necessary in vigorous term neonates and to assess the clinical impact of cord clamping timing on umbilical cord blood gas values.

STUDY

DESIGN

This retrospective observational study included 1156 term, singleton, low-risk vaginal births with first-minute Apgar scores >8, occurring across three institutional periods with differing cord clamping protocols (2022-2024). Umbilical artery or venous blood gas parameters were analyzed in relation to cord clamping timing: <60 s, 60-180 s, and ≥180 s.

RESULTS

Statistically significant differences in umbilical artery pH were observed among the clamping groups (p < 0.001), with greater acidosis noted when arterial sampling was performed after more than three minutes. However, all values remained within physiological limits. Higher 5-minute Apgar scores were associated with delayed clamping, suggesting improved neonatal adaptation. The rate of unsuccessful arterial sampling did not increase significantly with longer delays in cord clamping.

CONCLUSION

Immediate arterial cord blood sampling may not be necessary in vigorous term neonates following uncomplicated vaginal birth. Delayed cord clamping does not diminish the clinical value of cord blood gas analysis and appears to support neonatal transition. These findings support the safety of postponing sampling in favor of preserving a physiological birth process.