Clinical features and their associations with umbilical cord gas abnormalities.

Background: We seek to identify risk factors associated with abnormal umbilical artery cord gas (UACG).

Methods: This was a secondary analysis of the multicenter Consortium for Safe Labor dataset. This study included singleton, term deliveries with UACG available. Abnormal UACG was defined as pH≤7.0 or base excess >12 mmol/L. Odds Ratios were calculated using a multivariable logistic regression to determine clinical factors associated with abnormal UACG.

Results: 18,589 patients met inclusion criteria, with approximately 2% having an abnormal UACG. Those with prior Cesarean delivery (OR=1.49, 95% CI: 1.15-1.93), maternal diabetes (OR=1.67, 95% CI: 1.06-2.64), magnesium sulfate use (OR=1.81, 95% CI: 1.25-2.60), current Cesarean delivery (OR=2.56, 95% CI: 2.06-3.19), pre-eclampsia/HELLP (hemolysis, elevate liver enzymes, low platelet count) syndrome (OR=2.80, 95% CI: 1.79-4.36), and placental abruption (OR=4.81, 95% CI: 3.35-6.91) had increased odds of having abnormal UACG at delivery compared to those without.

Conclusions: Diabetes, pre-eclampsia, placental abruption, and a history of prior Cesarean delivery were all associated with abnormal UACG in this cohort of singleton, term deliveries. These findings indicate that patients with pre-existing risk factors may be at an increased likelihood of adverse neonatal outcomes.