Samuel C. Hughes, M.D., Chair
Committee on Obstetrical Anesthesia

here are several areas of controversy and change in obstetric anesthesiology. The cesarean delivery rate is rising and may soon escalate further because of cesarean delivery on maternal request. This occurs at a time when epidural analgesia for labor is being used more commonly and effectively and has finally been found “not guilty” of the charge that it increased the cesarean delivery rate! These issues as well as the proposed new “Practice Guidelines for Obstetric Anesthesia” are discussed in this obstetric anesthesia update.

Cesarean Delivery Rates
The cesarean delivery rate in the United States was 5.5 percent in 1970, but it had reached 29.1 percent by 2004. There are many possible and often complex reasons for this increase and they will be touched upon later in this update, but for many years, one aspect of this ongoing discussion has been the role that anesthesia plays. Progress in labor and the effect of regional analgesia have often been debated, but it took a new turn in the early to mid-1990s when several studies suggested that epidural analgesia increased the risk of cesarean delivery by as much as 12-fold.¹ Some studies demonstrated an even greater association between epidural analgesia and cesarean delivery when an epidural was placed before the parturient achieved a cervical dilation of 5 cm. In 2000, the American College of Obstetricians and Gynecologists (ACOG) Task Force on Cesarean Delivery recommended that “when feasible, obstetric practitioners should delay the administration of epidural anesthesia in nulliparous women until cervical dilation of 4-5 cm.”²

For some women, waiting for epidural analgesia until their cervix had dilated to 5 cm was extremely painful. The additional charge that the increased cesarean delivery rate was closely linked to epidural analgesia was difficult for patients as well as many practitioners of obstetric anesthesia. Was analgesia being offered with an increased risk of a surgical delivery?

Fortunately more recent studies and several meta-analyses have all concluded that epidural analgesia does not increase the rates of cesarean delivery. Further, the results of three randomized, controlled trials demonstrated no difference in the rate of cesarean deliveries between women who had received epidurals and women who had received only intravenous analgesia. In addition the issue of placing early epidurals (Does it cause an increase in cesarean delivery?) was put to rest with the study by Wong et al.³ This paper received a great deal of attention from the national press, including television interviews with Cynthia A. Wong, M.D., the first author of the paper, and William L. Camann, M.D., who wrote an editorial that accompanied the paper. Dr. Wong and her colleagues concluded that “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.” This work was confirmed in a more recent paper.⁴ The long trail of research, inflammatory rhetoric and committee and task force consideration and statements has finally led to a most positive outcome, in my view, with the publication of ACOG Committee Opinion No. 339 in June 2006: Analgesia and Cesarean Delivery Rates.¹

The committee opinion was good news and good science. The newly published opinion clearly stated that epidural analgesia does not increase the risks of cesarean delivery. It also noted the recent studies indicating that initiation of early neuraxial analgesia does not increase the risk of cesarean delivery.

As chair of the ASA Committee on Obstetrical Anesthesia, I immediately received e-mails asking if we must now put epidurals in every parturient at 2 cm cervical dilation. The answer is, of course, no. This is an individual decision based on the patient’s clinical situation, pain experienced and her preferences. This decision also is made after consultation with the obstetrician and the other skilled support personnel caring for the patient. However if an early epidural is requested, the service is available and there are no contraindications, it can be administered without concern for increasing the chances of a cesarean delivery. In my experience, most women at this early stage do not request an epidural, but I have long felt that timing of an epidural should largely be the patient’s decision.

Cesarean Delivery on Maternal Request
The “flip side” of the analgesia and cesarean delivery story is cesarean delivery on maternal request (CDMR). While epidural analgesia has been proven innocent with regard to the increasing cesarean delivery rate, CDMR may account for 4 percent to 18 percent of all cesarean deliveries,⁵ and this number is likely going to increase. Certainly the issue is getting more attention. The National Institutes of Health (NIH) State-of-the Science Conference statement “Cesarean Delivery on Maternal Request” was released in draft form in March 2006 and recently published.⁶ CDMR was defined as a “cesarean delivery for a singleton pregnancy on maternal request at term in the absence of any medical or obstetrical indications.” Forget labor and any issue of early epidurals — I’ll have my cesarean delivery at 39 weeks, if you don’t mind!

This is a complex subject with potentially profound implications for patients, medical practitioners, health care systems and society as a whole. David H. Chestnut, M.D., former chair of the Committee on Obstetrical Anesthesia, has provided an excellent editorial on this subject.⁵ The NIH panel concluded that there is insufficient evidence to evaluate fully the benefits and risks of CDMR as compared to a vaginal delivery. The panel also noted that the risks of placenta previa and accreta increase with cesarean delivery. Certainly CDMR is not for women who wish to have several children. While the concept of “elective” cesarean delivery versus difficult vaginal deliveries — and in some cases, urgent surgery in the middle of the night — may sound appealing to some, are we ready for the potentially increased morbidity?⁶ David L. Birnbach, M.D., the immediate past chair of the Committee on Obstetrical Anesthesia, was on this panel and contributed wisely, in my view. The panel stated: “Maternal request for cesarean delivery should not be motivated by unavailability of effective pain management. Efforts must be made to assure availability of pain management services for women.”⁶ I find it ironic that the labor epidurals that some years ago were said to increase the cesarean delivery rate may now help to keep the cesarean delivery rate down by providing analgesia and encouraging some women to forgo the trend toward “elective” cesarean delivery or cesarean delivery on maternal request. Patient-controlled epidural analgesia (PCEA) also may help to encourage vaginal deliveries and improve patient satisfaction. The full impact of this NIH State-of-the-Science Conference statement is unknown, but its seemingly neutral overall recommendations on CDMR, which will likely be interpreted as permissive, “signals the removal of the last substantive deterrent against performance of cesarean delivery in the absence of an obstetric or medical indication.”⁵ This is an evolving story, so stay tuned!

Practice Guidelines for Obstetric Anesthesia: Update Coming Your Way Soon!
The Task Force on Obstetric Anesthesia, chaired by Joy L. Hawkins, M.D., and staffed by many capable members from the obstetric anesthesiology community, is presently revising and updating the previous “Practice Guidelines for Obstetrical Anesthesia” published in 1999.⁷ The guidelines have now received a careful review and reconsideration by the task force. There have been two public presentations of the draft at the International Anesthesia Research Society in March and the Society for Obstetric Anesthesia and Perinatology in May 2006, with comments from practitioners taken into consideration. The final document will be presented at the 2006 ASA meeting in Chicago where there will be a further chance to comment before it is voted on by the ASA House of Delegates.

There is a very methodical and deliberate process to update guidelines, and it involves the thoughts of as many members as possible. I have reviewed the near final draft (July 2006) and feel that it is extremely well done and will be quite useful. For example, under Intrapartum Platelet Count, the proposed recommendation now states: “A routine platelet count is not necessary in the healthy parturient.” The section on Anesthetic Care for Labor and Vaginal Delivery is much broader and includes recommendations on early epidural analgesia (it is O.K. if needed), early epidural insertion in complicated patients (it may help decrease general anesthesia) and PCEA (it is flexible and effective and requires fewer anesthetic interventions), to name but a few of the updates. I think this document will be extremely useful to all of us who practice obstetric anesthesia. Hopefully it will be approved by ASA in October and published in early 2007 in Anesthesiology, so look for this document — it’s a good thing!

Obstetric anesthesiology continues to evolve and change. Epidural analgesia has a clean bill of health, and there is an increasing use of PCEA. The increasing cesarean section rate, however, may be magnified by CDMR. We are indeed practicing in interesting times!


References:
1. American College of Obstetricians and Gynecologists (ACOG). Analgesia and cesarean delivery rates. ACOG Committee Opinion No. 339. June 6, 2006; 339:1487-1488.
2. American College of Obstetricians and Gynecologists (ACOG). Evaluation of cesarean delivery. Washington, DC: ACOG; 2000.
3. Wong CA, Scavone BM, Peaceman AM, et al. The risk of cesarean delivery with neuraxial analgesia given early versus late in labor. N Engl J Med. 2005; 352:655-665.
4. 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; 194:600-605.
5. Chestnut DH. Cesarean delivery on maternal request: Implications for anesthesia providers (Editorial). Int J Obstet Anesth. 2006; in press.
6. National Institutes of Health State-of-the Science Conference Statement: Cesarean Delivery on Maternal Request. March 27-29. Obstet Gynecol. 2006; 1077:1386-1397. Available at: <consensus.nih.gov/2006/2006Cesarean SOS027html.htm>.
7. American Society of Anesthesiologists. Practice guidelines for obstetrical anesthesia. Task Force on Obstetrical Anesthesia. Anesthesiology. 1999; 90:600-611.

Samuel C. Hughes, M.D., is Professor of Clinical Anesthesia and Perioperative Care, University of California-San Francisco, and Director of Obstetric Anesthesia, San Francisco General Hospital.