The risk of cesarean delivery with neuraxial analgesia given early versus late in labor.
BACKGROUND
Epidural analgesia initiated early in labor (when the cervix is less than 4.0 cm dilated) has been associated with an increased risk of cesarean delivery. It is unclear, however, whether this increase in risk is due to the analgesia or is attributable to other factors.


METHODS
We conducted a randomized trial of 750 nulliparous women at term who were in spontaneous labor or had spontaneous rupture of the membranes and who had a cervical dilatation of less than 4.0 cm. Women were randomly assigned to receive intrathecal fentanyl or systemic hydromorphone at the first request for analgesia. Epidural analgesia was initiated in the intrathecal group at the second request for analgesia and in the systemic group at a cervical dilatation of 4.0 cm or greater or at the third request for analgesia. The primary outcome was the rate of cesarean delivery.


RESULTS
The rate of cesarean delivery was not significantly different between the groups (17.8 percent after intrathecal analgesia vs. 20.7 percent after systemic analgesia; 95 percent confidence interval for the difference, -9.0 to 3.0 percentage points; P=0.31). The median time from the initiation of analgesia to complete dilatation was significantly shorter after intrathecal analgesia than after systemic analgesia (295 minutes vs. 385 minutes, P<0.001), as was the time to vaginal delivery (398 minutes vs. 479 minutes, P<0.001). Pain scores after the first intervention were significantly lower after intrathecal analgesia than after systemic analgesia (2 vs. 6 on a 0-to-10 scale, P<0.001). The incidence of one-minute Apgar scores below 7 was significantly higher after systemic analgesia (24.0 percent vs. 16.7 percent, P=0.01).


CONCLUSIONS
Neuraxial analgesia in early labor did not increase the rate of cesarean delivery, and it provided better analgesia and resulted in a shorter duration of labor than systemic analgesia.
Wong
Cynthia A
CA
Department of Anesthesiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA. c-wong2@northwestern.edu
Scavone
Barbara M
BM
Peaceman
Alan M
AM
McCarthy
Robert J
RJ
Sullivan
John T
JT
Diaz
Nathaniel T
NT
Yaghmour
Edward
E
Marcus
R-Jay L
RJ
Sherwani
Saadia S
SS
Sproviero
Michelle T
MT
Yilmaz
Meltem
M
Patel
Roshani
R
Robles
Carmen
C
Grouper
Sharon
S
D000328:Adult; D015360:Analgesia, Epidural / Q000009:adverse effects; D016362:Analgesia, Obstetrical / Q000009:adverse effects; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000494:pharmacology / Q000627:therapeutic use; D002585:Cesarean Section / Q000706:statistics & numerical data*; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D004091:Hydromorphone / Q000494:pharmacology / Q000627:therapeutic use; D007231:Infant, Newborn; D007275:Injections, Intravenous; D007278:Injections, Spinal; D007743:Labor, Obstetric / Q000187:drug effects*; D015999:Multivariate Analysis; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D011247:Pregnancy; D011256:Pregnancy Outcome; D012306:Risk; D013997:Time Factors
D000701:Analgesics, Opioid; D004091:Hydromorphone; D005283:Fentanyl