Umbilical cord blood gases sampling in low-risk vaginal deliveries as a predictor of adverse neonatal outcome.

INTRODUCTION

There is no clear correlation between abnormal umbilical cord blood gas studies (UCGS) and adverse neonatal outcome in low-risk deliveries. We investigated the need for its routine use in low-risk deliveries.

METHODS

We retrospectively compared maternal, neonatal, and obstetrical characteristics among low-risk deliveries (2014-2022) between "normal" and "abnormal" pH groups: A:normal pH ≥ 7.15; abnormal pH < 7.15; B: normal pH ≥ 7.15 and base excess (BE) > - 12 mmol/L; abnormal pH < 7.15 and BE ≤ We retrospectively compared 12 mmol/L; C: normal pH ≥ 7.1; abnormal pH < 7.1; D: normal pH > 7.1 and BE > - 12 mmol/L; abnormal pH < 7.1 and BE ≤ - 12 mmol/L.

RESULTS

Of 14,338 deliveries, the rates of UCGS were: A-0.3% (n = 43); B-0.07% (n = 10); C-0.11% (n = 17); D-0.03% (n = 4). The primary outcome, composite adverse neonatal outcome (CANO) occurred in 178 neonates with normal UCGS (1.2%) and in only one case with UCGS (2.6%). The sensitivity and specificity of UCGS as a predictor of CANO were high (99.7-99.9%) and low (0.56-0.59%), respectively.

CONCLUSION

UCGS were an uncommon finding in low-risk deliveries and its association with CANO was not clinically relevant. Consequently, its routine use should be considered.