Effects of immediate versus delayed pushing during second-stage labor on fetal well-being

Background: Although there are two methods of caring for women with epidural anesthesia during second-stage labor (coached closed-glottis pushing immediately at 10-cm cervical dilation or delayed pushing until the woman feels the urge to push, passive fetal descent, and encouragement of open-glottis pushing when the woman has the urge to push), there are limited data concerning which method is most optimal for fetal well-being. Objective: To evaluate effects on fetal well-being, as measured by fetal oxygen saturation, of two different methods of second-stage labor nursing care for women with epidural anesthesia. Methods: Forty-five nulliparous women who had progressed to the second stage were randomized to 1 of 2 groups (immediate or delayed pushing). Fetal oxygen saturation was continuously monitored and values at 10 cm, initiation of pushing and immediately prior to birth, as well as the amount of time that fetal oxygen saturation values were abnormal (< 30 %) were compared between groups. Also evaluated were additional measures of fetal well-being such as fetal heart rate patterns, Apgar scores, and umbilical cord blood gases and maternal outcomes including length of labor, method of birth, and perineal status. Results: There was a significant difference between groups in fetal oxygen desaturation during the second stage (immediate: M = 12.5; delayed: M = 4.6) F(1, 43) = 12.24, p =.001, and in the number of >= 2-min epochs of fetal oxygen saturation < 30 % (immediate: M = 7.9; delayed: M = 2.7), F(1, 43) = 6.23, p = .02. There were more variable decelerations of the fetal heart rate in the immediate pushing group (immediate: M = 22.4; delayed: M = 15.6) F(1, 43) = 5.92, p =.02. There were no differences in length of labor, method of birth, Apgar scores, or umbilical cord blood gases. Women who pushed immediately had more perineal lacerations (immediate: n 13; delayed: n = 5) chi(2)(1, N = 45) = 6.54, p = .01. Discussion: Delayed pushing results in less fetal oxygen desaturation and less >= 2-min epochs of fetal oxygen saturation < 30 % during second-stage labor than the immediate pushing method; thus, delayed pushing is more favorable for fetal well-being as measured by fetal oxygen saturation.