Effect of maternal epidural analgesia on fetal intrapartum oxygen saturation.

The use of maternal epidural analgesia in labor may be associated with nonreassuring fetal heart rate (FHR) patterns. Fetal oxygen saturation (FSpO2) monitoring may improve assessment of fetal well-being during this time. Mean FSpO2 values were compared over seven 5-minute epochs: 5 minutes prior to an epidural event (combined insertion of epidural/top-up epidural analgesia and infusion pump bolus), to 30 minutes following the event, including possible effects of maternal position and FHR pattern on FSpO2 values. Mean FSpO2 values were significantly different between the 5 minutes prior (49.5%) versus 16-20 minutes (44.3%, p <0.05), 21-25 minutes (43%, p <0.01), and 26-30 minutes (43.8%, p <0.05) epochs; and 6-10 minutes (48.3%) versus 21-25 minutes (43%, p <0.05) epochs, but were not influenced by FHR pattern or maternal position. There were no differences in mean FSpO2 values following administration of an epidural infusion bolus. We conclude that fetal oxygenation was affected following initial or top-up epidural analgesia and that fetal intrapartum pulse oximetry may be useful in assessing fetal status following these events.