Lactate concentration in amniotic fluid: a good predictor of labor outcome

Previous publications have suggested that high levels of lactate in amniotic fluid (AF) correlate with dysfunctional labor. The aim of this study was to investigate whether lactate concentration in AF together with the partogram is a better predictor of operative intervention in dysfunctional labor than the partogram alone.

A prospective observational study was carried out of 825 laboring women. Samples of AF were collected and the lactate concentration was analyzed at the bedside during labor. The main outcome of the study was the method of delivery (operative/spontaneous vaginal) in relation to the concentration of lactate in AF. Logistic regression was used to estimate the association between lactate concentration in AF and labor outcome and to adjust for well-known risk factors for dysfunctional labor.

385/825 women had an arrested labor according to the partogram, and 193 of them were delivered operatively. High lactate in AF (>10.1 mmol/l) when labor arrested was associated with an increased risk of operative intervention due to dysfunctional labor (adjusted OR, 5.4, 95% CI, 3.2-9.1). Low levels of lactate in AF (<10.1 mmol/l) were associated with an increased probability of spontaneous vaginal delivery (adjusted OR, 2.7, 95% CI, 1.7-4.8).

The partogram together with the concentration of lactate in AF is a better predictor of operative intervention in dysfunctional labor than the partogram alone.