ABSTRACT: To test the hypothesis that long, hard Valsalva pushing during second stage labor may increase fetal acidosis and decrease neonatal Apgar scores, ten women with normal pregnancies and first stage labors were randomly assigned to a long Valsalva pushing group or a short, open glottis pushing group. Neonatal outcomes were measured by umbilical vessel blood gasses. Open glottis pushers showed a non-significant trend toward longer second stage labors and higher umbilical artery pH. Umbilical vein pH was significantly higher among open glottis pushers. Long Valsalva pushers had less frequent expulsive contractions.

Whether women use long Valsalva or open glottis pushes may be only one of several factors which affect neonatal outcome, including not only the length and force of the push but also the condition of the fetus at the onset of pushing, the frequency and length of contractions during second stage, and the speed of delivery after crowning of the fetal head.