Does oxytocin augmentation increase perinatal risk in primigravid labor? DavidJ. Cahill, MB, Peter C. Boylan. MAO, and Colm O'Herlihy, MD Dublin, Ireland To assess the influence of high-dose oxytocin augmentation of spontaneous labor, a consecutive series of 30,874 primigravid term deliveries were analyzed for adverse perinatal outcome. In spite of a longer mean duration of labor, the frequencies of asphyxial perinatal death, neonatal seizures, and abnormal neonatal neurologic behavior were not significantly increased in 14,119 (45%) oxytocin-treated patients. There was no case of uterine rupture in any primigravid labor during the study. These results from 13 years of clinical practice provide reassurance about maternal and fetal safety if oxytocin is used as part of a protocol of active management to correct dystocia when spontaneous primigravid labor with vertex presentation fails to progress. (AM J OBSTET GVNECOL 1992;166:847-50.)
Key words: High-dose oxytocin augmentation, active management of labor, adverse perinatal outcome
It has been suggested that dystocia is the primary
cause of the rising international rates of cesarean section in first labors. 1-' Early diagnosis and correction of dystocia in primigravid women have been shown to effectively counter this rising trend in both Europe'-6 and North America.7.8 High-dose oxytocin administration forms an essential part of programs of active augmentation by improving uterine contractility and preventing prolonged labor. 9 It has, however, been suggested that the price to be paid for more efficient uterine activity may be an increased risk of perinatal asphyxia resulting from myometrial hyperstimulation. IO- 12 At the National Maternity Hospital in Dublin, a standard regimen of high-dose (6 to 40 m U / min) intravenous oxytocin therapy has been used in slowly progressing primigravid labor for >20 years. The fact that no case of uterine rupture has resulted from this regimen underlines its maternal safety in relation to augmented primigravid labor. l ! To reassess the influence of oxytocin on the incidence of perinatal asphyxia, we analyzed our experience with oxytocin augmentation in spontaneous primigravid labor at term. Only primigravid women were included because of the welldocumented risks of uterine hyperstimulation in multigravid women. 1
Key words: High-dose oxytocin augmentation, active management of labor, adverse perinatal outcome
It has been suggested that dystocia is the primary
cause of the rising international rates of cesarean section in first labors. 1-' Early diagnosis and correction of dystocia in primigravid women have been shown to effectively counter this rising trend in both Europe'-6 and North America.7.8 High-dose oxytocin administration forms an essential part of programs of active augmentation by improving uterine contractility and preventing prolonged labor. 9 It has, however, been suggested that the price to be paid for more efficient uterine activity may be an increased risk of perinatal asphyxia resulting from myometrial hyperstimulation. IO- 12 At the National Maternity Hospital in Dublin, a standard regimen of high-dose (6 to 40 m U / min) intravenous oxytocin therapy has been used in slowly progressing primigravid labor for >20 years. The fact that no case of uterine rupture has resulted from this regimen underlines its maternal safety in relation to augmented primigravid labor. l ! To reassess the influence of oxytocin on the incidence of perinatal asphyxia, we analyzed our experience with oxytocin augmentation in spontaneous primigravid labor at term. Only primigravid women were included because of the welldocumented risks of uterine hyperstimulation in multigravid women. 1
