The acid-base balances of 63 neonates delivered either spontaneously or by the vacuum extractor or low forceps were compared. The outcome was similar in neonates delivered by vacuum extractor or forceps. However, significant differences were noted in the pH and base deficit of infants born by instrumental versus spontaneous delivery. These differences were no longer present when groups with similar duration in the second stage of labor were compared. We conclude that the use of instruments for outlet vaginal delivery carries no additional risk for the fetus.