Reducing forceps deliveries following epidural analgesia

Date: July, 1990

The widespread use of epidural analgesia to improve pain control during labor has been associated with a concomitant increase in the number of forceps-assisted deliveries in Great Britain. This increase in forceps delivery is generally attributed to an increase in the number of cases with malposition of the occiput, combined with the loss of the urge to bear down with contractions during the second stage of labor. Attempts to improve the rate of spontaneous delivery by allowing epidural analgesia to wear off during the second stage of labor have not been successful.

In animals, a neurohumoral reflex releases oxytocin in response to distention of the birth canal. If this reflex exists in humans, it may be an important factor in the descent and rotation of the fetus during the second stage of labor. The use of epidural analgesia may eliminate this reflex by blocking conduction pathways in spinal autonomic nerves.

Based on this reasoning, Saunders and colleagues conducted a randomized placebo-controlled trial using oxytocin during the second stage of labor. This double-blind study included 226 primiparous patients with adequate epidural analgesia. Patients received either oxytocin or placebo by intravenous infusion at diagnosis of full cervical dilation. The two groups of patients were comparable for variables such as age and height. The oxytocin infusion was started at a rate of 2 mU per minute, with the rate doubled every 20 minutes, to a maximum of 16 mU per minute if there was no clinical contraindication.

The second stage of labor was significantly shorter in the patients receiving oxytocin. This group also had fewer non-rotational forceps deliveries and less perineal trauma than the patients receiving placebo. No difference was observed in the number of rotational forceps deliveries performed for malposition of the occiput. No adverse effects were observed in the fetal condition, either at birth or during the early puerperium in the group receiving oxytocin.

The authors conclude that oxytocin infusion in primiparas during the second stage of labor may reduce the high rate of forceps deliveries associated with epidural analgesia but does not correct malposition of the fetal occiput. (British Medical Journal, December9,1989, vol. 299, p. 1423.)

COPYRIGHT 1990 American Academy of Family PhysiciansCOPYRIGHT 2004 Gale Group

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