Arterial blood gases in newborn infants: Early extraction without prior clamping versus extraction after delayed clamping

Abstract

Objectives: To compare the postpartum arterial blood gas parameters recorded early before cord clamping and after delayed cord clamping (DCC). To explore adverse effects and complications of the cord blood gas collection technique without clamping.

Design: Randomised controlled trial.

Setting: Birthing room of La Ribera University Hospital (Valencia, Spain).

Participants: 122 full-term infants born between February 2020 and January 2021. Two groups were established: the experimental group (early sampling prior to clamping and sampling again after DCC) and the non-experimental group (sampling only after DCC).

Measurements and findings: The comparison of arterial blood gas parameters was made using the Student t-test, while the Fisher's exact test was used to compare the proportion of the adverse effects recorded. The pH and base excess values in the experimental group were significantly greater when the sampling was performed without prior clamping. No statistically significant differences were observed in relation to pCO₂ or the appearance of adverse effects between the two groups. No complications were recorded.

Key conclusions and implications for practice: The pH and base excess values were higher when the arterial blood gas measurements were made prior to performing the umbilical cord clamping than when the sampling was performed after the DCC. Arterial blood gas sampling without prior clamping was found to be safe, since no complications or increased adverse effects were observed. The use of this technique is therefore advised in normal births of full-term infants.

Keywords: Blood gas analysis; Newborn; Nurse midwives; Term birth; Umbilical cord.