We appreciate the interest of Drs. Wong, Scavone, Sullivan, and McCarthy in our work1and thank them for their comments. The association between neuraxial analgesia at different stages of cervical dilation and the risk of cesarean delivery is an important issue and has been debated for decades. We performed a 5-yr randomized controlled trial, initiated in January 2003, to investigate the hypothesis that early epidural analgesia at cervical dilation of 1.0 cm or more would not increase the risk of cesarean delivery or prolonged labor, and found results that were consistent with those reported by Wong et al .2,3and Ohel et al .4 

In our study, the median diameter of cervical dilation was 1.6 cm (interquartile range, 1.1–2.8 cm) in the early epidural analgesia, which was smaller than that reported by Wong et al . (median, 2.0 cm) or Ohel et al . (mean, 2.1 cm). In our publication, we described published data regarding neuraxial analgesia at a cervical dilation of 2.0 cm and which provide support for the use of epidural analgesia in nulliparous analgesia. In the description, we did not precisely and explicitly state cervical diameter, which resulted in a misunderstanding by these authors that our citations were incorrect. We apologize for this confusion. In addition, these previous publications included primarily a Western population, and it is uncertain whether the results would be similar in an Asian population. Therefore, we did our trial to test the effect of early epidural analgesia at a median cervical dilation less than 2.0 cm on the risk of cesarean delivery in Chinese women.

In addition, Wong et al . point out that our definition of the length of labor in the table was inconsistent with the footnote explanation in table 2 of our article. The authors are correct, and we have requested that a correction be published, which will appear in an upcoming issue of this journal. We clarify again that, in our study, the length of labor refers to the period from the onset of regular uterine contraction to the time after delivery of placenta. Using this definition point, there was no statistically significant difference in the length of labor between groups. Moreover, the analgesia time in both groups was longer than the labor time, mainly because epidural analgesia was not stopped until about 1 h later after the placenta was delivered to reduce early postpartum pain resulting from uterine contraction or perineal trauma during delivery.

*The Affiliated Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing, Jiangsu, China. zfwang50@njmu.edu.cn

Wang F, Shen X, Guo X, Peng Y, Gu X: Labor Analgesia Examining Group: Epidural analgesia in the latent phase of labor and the risk of cesarean delivery: A five-year randomized controlled trial. Anesthesiology 2009; 111:871–80
Wong CA, Scavone BM, Peaceman AM, McCarthy RJ, Sullivan JT, Diaz NT, Yaghmour E, Marcus RJ, Sherwani SS, Sproviero MT, Yilmaz M, Patel R, Robles C, Grouper S: The risk of cesarean delivery with neuraxial analgesia given early versus late in labor. N Engl J Med 2005; 352:655–65
Wong CA, McCarthy RJ, Sullivan JT, Scavone BM, Gerber SE, Yaghmour EA: Early compared with late neuraxial analgesia in nulliparous labor induction: A randomized controlled trial. Obstet Gynecol 2009; 113:1066–74
Ohel G, Gonen R, Vaida S, Barak S, Gaitini L: Early versus late initiation of epidural analgesia in labor: Does it increase the risk of cesarean section? A randomized trial. Am J Obstet Gynecol 2006; 194:600–5