The Impact of neuraxial analgesia on the dynamic of labor and neonatal outcome

Objective: The pattern of labor progression in contemporary practice differs significantly from the Friedman curve. Induction of labor, oxytocin use, neuroaxial analgesia, and fetal heart rate monitoring are very common in contemporary practice. The aim of our study is to value the effects of analgesia during labor and above neonatal outcome.

Study Design: This study was attended in our Hospital where the rate of neuroaxial analgesia in labor increased from 30 to 85% in ten years. We selected 275 singleton, nulliparous, term pregnancies with spontaneous onset of labor and vertex presentation in neuroaxial analgesia. We studied labor's duration, instrumental delivery, oxytocin use and neonatal outcome (APGAR Score at 1st and 5 st minute after birth).

Results: Despite to a rapid and dramatic increase in neuraxial analgesia during labor, rates of cesarean delivery overall and for dystocia remained the same. Overall instrumental delivery did not increase, nor the duration of the first stage and the active phase of labor. However, the second stage of labor was significantly longer by about 20 minutes. The data of Apgar Score showed in table 1 and graphic 2.

Conclusion: Neuroaxial analgesia during labor does not increase the risk of cesarean delivery nor oxytocin use or instrumental delivery. The duration of labor active phase appears unchanged, instead the second stage of labor is prolonged. There is no evidence a longer second stage of labor may be a serious disadvantage to the fetus, if adequate monitoring is provided. In nulliparous under analgesia, according to the ACOG, it can last until 3 hours. We suggest it's necessary to wait parturient feels the premyth before actively pushing, in the mean time it's important to maintain a good pain control and reassuring cardiotocography conditions. This assertion is supported by many studies published in licterature, indicating an improvement of maternal and neonatal outcome if pushing is delayed.

Table 1– Apgar Score at the 1’ and 5’

SCORE	APGAR 1’	APGAR 5’
5	2 newborns	0 newborns
7	10 newborns	0 newborns
8	39 newborns	7 newborns
9	224 newborns	43 newborns
10	0 newborns	225 newborns

Fig. 2: Apgar Score

Literatur: · Zhang J, Troendle JF, Yancey MK.Reassessing the labor curve in nulliparous women. Am J Obstet Gynecol. 2002 Oct;187(4):824-8. · American College of Obstetricians and Gynecologists (ACOG). Obstetric analgesia and anesthesia. Washington(DC): American College of Obstetricians and Gynecologists (ACOG); 2002. · Janni W., Kainer F., The prognostic impact of a prolonged second stage of labor on maternal and fetal outcome. Acta Obstet Gynecol Scand 2002; 81: 214–221. · Fraser, William D. MD c; for The PEOPLE (Pushing Early or Pushing Late with Epidural) Study Group. American Journal of Obstetrics & Gynecology. 182(5):1158-1164, May 2000.

labor - neonatal outcome - neuraxial analgesia