How well are we collecting umbilical cord lactate and gas samples?

Aims: The aim of this study is to measure staff compliance with the local umbilical cord lactate (UCL) sampling guideline and investigate the quality of paired UCG samples at a tertiary maternity unit.

Methods: We performed a retrospective consecutive sampling of 100 babies delivered via emergency caesarean section and 50 babies with each of all other guideline-based indications for UCL sampling born on and before 31 December 2021. Data were extracted from physical and electronic records. Compliance with guideline-based indications for UCL at birth was measured. The proportion of valid UCG samples was calculated. Samples were considered invalid under the following cases: (i) inadvertently collecting from the same vessel, (ii) switching arterial and venous samples, (iii) collecting from only one vessel or (iv) committing errors during sample collection and handling.

Results: Of the samples collected at birth from 321 babies, 280 (87%) had UCL. Small for gestational age and concerns about fetal well-being in labour were indications associated with poorer compliance, 66% and 78%, respectively. About 99 (44%) babies of 226 babies with UCG performed had valid UCG samples. The most common reasons for invalid samples were collection and handling errors (22%) and inadvertent collection from the same vessel (15%).

Conclusions: Generally, compliance with the guidelines is good. However, invalid UCG samples were more frequent than expected.