"A CSE technique provides more rapid onset of analgesia and more first-stage analgesia compared with a traditional epidural technique," concludes the new study, led by Dr David Gambling of Sharp Mary Birch Hospital for Women and Newborns, San Diego, Calif.

Epidural versus CSE for Pain Control during Labor The researchers compared CSE with epidural analgesia in 800 healthy women requiring pain control during labor. One group received standard epidural analgesia. In this technique, local anesthetic and pain medications are injected into the epidural space -- inside the membranes (dura) covering the spinal cord.

The other group received CSE, which starts with medications injected into the intrathecal space -- the deeper space directly around the spinal cord. After initial epidural or intrathecal injection, both groups received patient-controlled epidural analgesia. The effectiveness of pain relief, rated on a 0-to-10 scale, was compared at different times during labor and delivery.

During the first stage of labor, the typical pain score was 1.4 for women receiving CSE versus 1.9 for those receiving standard epidural analgesia. This 0.5-point difference was statistically significant. Women in the CSE group also had a shorter time to complete pain control -- an average of 11 minutes faster than the epidural group. There was no little or no difference in pain scores during the second stage of labor or at delivery.

Women in the CSE group were less likely to need additional epidural "top-up" doses to maintain good pain control. There was no significant difference in the type of delivery, with cesarean section rates of 14 to 16 percent. Side effects were also similar between groups.

Despite Differences, Both CSE and Epidural Are 'Excellent Options' Epidural analgesia has been used to provide labor pain relief for more than 40 years, with modern techniques providing better pain control with fewer side effects. Since the early 1990s, the CSE technique has become popular because it provides more rapid pain relief with less leg weakness -- the main side effect of epidural analgesia.

Despite previous studies, the relative advantages of these options for labor analgesia have been unclear. The new study is the first to directly compare epidural versus CSE for labor analgesia in a busy private maternity hospital.

The results suggest that CSE provides significantly faster and better pain relief during the first stage of labor, compared to the traditional epidural technique. The differences in pain control during early labor are small but significant, Dr Gambling and colleagues note. They write, "[W]hen one considers the fact that fewer top-up doses were required to achieve the improvement in analgesia, it would seem that on balance CSE is the superior technique for first-stage analgesia."

But that doesn't mean that CSE is always the better choice, according to an accompanying editorial by Drs Jessica L. Booth and Peter H. Pan of Wake Forest University School of Medicine. They write, "The findings…highlight that fact that both CSE and epidural analgesia are an excellent analgesic option during labor." Drs Booth and Pan believe that inconsistent results reported by previous studies "may be explained, in part, by the lack of a standard CSE or epidural technique."