Arterial cord blood lactate at birth correlates with duration of pushing efforts

Abstract

Objective: To evaluate the impact of the duration of pushing efforts on arterial cord blood lactate values. Methods: This was a prospective observational study of 124 consecutive normal vaginal deliveries in a tertiary teaching hospital. Arterial cord blood lactate was determined immediately at birth with a test strip method. Univariate and multivariate analyses were performed to check for clinical determinants of lactate levels. The main measure was lactate according to the duration of pushing efforts. Results: Arterial cord lactates increased significantly and were strongly correlated with the duration of pushing efforts, independent of gestational age and birthweight. Women pushing for more than 20 min had higher arterial cord blood lactates (4.9 ± 1.4 vs. 3.3 ± 1.16 mM, respectively) and a higher rate of lactates >6 mM (18 vs. 3%) than those pushing for less than 20 min. Conclusion: At normal delivery, arterial cord blood lactates increase significantly with the duration of pushing efforts. Pushing for more than 20 min is associated with an increased risk of metabolic acidosis in the neonate. Further studies are required to evaluate the clinical significance of these observations. Copyright © 2009 S. Karger AG.