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

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

Automated summary

There is no significant correlation between abnormal umbilical cord blood gas studies (UCGS) and adverse neonatal outcome in low-risk deliveries. Therefore, the routine use of UCGS in low-risk deliveries should be reconsidered.