Q&A

Does delayed pushing reduce difficult deliveries for nulliparous women with epidural analgesia?

Author and Disclosure Information

Fraser,WD, Marcoux S, Krauss I, Douglas J, Goulet C, Boulvain M. Multicenter, randomized, controlled trial of delayed pushing for nulliparous women in the second stage of labor with continuous epidural analgesia. Am J Obstet Gynecol 2000; 182:115-72.


 

BACKGROUND: Epidural analgesia, though effective, can prolong second stage labor and increase midpelvic delivery and maternal and neonatal morbidity. Studies indicate delayed pushing may decrease the need for forceps delivery. The authors of this randomized trial assessed the outcomes of a delayed pushing strategy of labor management.

POPULATION STUDIED: A total of 1862 nulliparous women were enrolled at 12 sites in Canada, Switzerland, and the United States. Enrollment criteria included more than 37 weeks’ gestation, vertex singleton presentation, normal fetal heart status, and effective continuous epidural analgesia. The average age of participants was 28 years, and more than 94% were white or Asian; other risk factors were not described. The high reported episiotomy rate (41%) suggests that the settings encouraged obstetric intervention, and the lack of information about intrapartum routines and other obstetric risk factors makes assessment of comparability difficult.

STUDY DESIGN AND VALIDITY: At complete dilatation the women were randomized (allocation concealment uncertain) to a pushing or delayed pushing group. Pushing in the latter group was discouraged for 2 hours unless there was an irresistible urge to push, the fetal head was at the perineum, or there was a medical indication to hasten delivery. Oxytocin use was standardized. Analysis was by intention to treat with control for potential confounding by the Mantel-Haenszel method.

OUTCOMES MEASURED: The primary outcome was difficult deliveries, defined as second stage cesarean section, midpelvic forceps or vacuum delivery, low pelvic forceps, or rotation of fetal head more than 45 degrees, or as any operative vaginal delivery preceded by manual rotation of the head 45 degrees. Secondary maternal outcomes included lacerations, blood loss, peripartum fever, and blood transfusions, as well as a postpartum survey of the mother’s sense of control during her labor and delivery. Pediatric outcomes included cord pH, Apgar scores, neonatal intensive care unit admission, and a neonatal morbidity index. Patient satisfaction and cost of care were not addressed.

RESULTS: Difficult deliveries were reduced in the delayed pushing group (relative risk=0.79; 95% confidence interval, 0.66-0.95; number needed to treat [NNT]=21). The most pronounced difference was in reduced midpelvic procedures; stratification by oxytocin use or other variables yielded no difference in difficult deliveries. The protective effect of delayed pushing on difficult delivery was greatest for women who had a fetus in a transverse or posterior position (NNT=8) or with a fetal station above +2 (NNT=17). Mothers in the delayed pushing group had a higher rate of intrapartum fever but no significant differences in antibiotic use, postpartum fevers, or any other outcome. The groups were similar in the mother’s reported sense of control. Infants in the delayed pushing group had a higher rate of cord pH <7.10, but there was no significant difference in the neonatal morbidity index scores or in specific adverse outcomes.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Delayed pushing for up to 2 hours after full cervical dilatation in nulliparous women receiving epidural analgesia is safe and may lower the risk of difficult deliveries. This may be especially true in settings with a high rate of routine obstetric interventions. Future studies should include more power for specific adverse pediatric outcomes and should address the generalizability of delayed pushing to patients of color and to a less interventional obstetric milieu. In the meantime, clinicians should allow patients to delay pushing, if close fetal monitoring is in place.

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