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New Lamaze International Epidural Infographic – Information, Not Judgment

November 4th, 2014 by avatar

Lamaze_EpiduralInfographic_FINALAs a follow up to Henci Goer’s recent analysis of the the Cochrane Systematic Review of the just released epidural study - Early versus late initiation of epidural analgesia for labour,  I wanted to share the newest Lamaze International infographic “Is An Epidural My Only Option?” geared for expectant families.  This fact sheet provides information not only about the epidural, it shares the risks and benefits.  The infographic discusses how to reduce risks and improve outcomes when laboring people choose to use one, such as trying other things first before asking for an epidural and changing positions frequently after the epidural is administered.

Additionally, there are several suggestions for alternatives to an epidural, which some people may find really helps to minimize pain, including using a doula for labor and birth support.  Encouraging families to ask questions about alternatives of their health care providers, choosing a facility that supports alternative forms of pain relief and discussing with their partners how the partner can help them to cope during labor.

I really appreciate the strong encouragement for families to take a Lamaze Childbirth Class in order to learn more about labor and birth and the coping skills that can promote a safe and health birth for mother and baby.  My childbirth classes are chock full of positions, techniques and tips to help reduce pain, maximize comfort and promote normal birth.  We thoroughly cover pain medication options as well, and families leave confident that they can effectively ask for and receive the information they need to make a decision about what, if any, medications they will choose during labor to help with pain.

I invite you to head over and check out the new epidural infographic, consider sharing the print or electronic version and checking out all the wonderful Lamaze resources on the website for educators.  Your students and clients can find the same information on the parent site!

Which infographic is your favorite? Which one do you use and refer to most frequently?  Let us know in the comments section below.

 

Childbirth Education, Medical Interventions, Push for Your Baby , , ,

Epidural Analgesia: To Delay or Not to Delay, That Is the Question

October 23rd, 2014 by avatar

By Henci Goer

Unless you have been “off the grid” on a solitary trek, surely you have read and heard the recent flurry of discussion surrounding the just released study making the claim that the timing of when a woman receives an epidural (“early” or “late” in labor) made no difference in the rate of cesarean delivery.  Your students and clients may have been asking questions and wondering if the information is accurate.  Award winning author and occasional Science & Sensibility contributor Henci Goer reviews the 9 studies that made up the Cochrane systematic review: Early versus late initiation of epidural analgesia for labour to determine what they actually said.  Read her review here and share if you agree with all the spin in the media about this new research review. Additionally, head on over to the professional and parent Lamaze International sites to check out the new infographic on epidurals to share with your students and clients.- Sharon Muza, Science & Sensibility Manager. 

Epidural infographic oneArticles have been popping up all over the internet in recent weeks citing a new Cochrane systematic review- Early versus late initiation of epidural analgesia for labour, concluding that epidural analgesia for labor needn’t be delayed because early initiation doesn’t increase the likelihood of cesarean delivery, or, for that matter, instrumental vaginal delivery (Sng 2014). The New York Times ran this piece. Some older studies have found that early initiation appeared to increase likelihood of cesarean (Lieberman 1996; Nageotte 1997; Thorp 1991), which is plausible on theoretical grounds. Labor progress might be more vulnerable to disruption in latent than active phase. Persistent occiput posterior might be more frequent if the woman isn’t moving around, and fetal malposition greatly increases the likelihood of cesarean and instrumental delivery. Which is right? Let’s dig into the review.

The review includes 9 randomized controlled trials of “early” versus “late” initiation of epidural analgesia. Participants in all trials were limited to healthy first-time mothers at term with one head-down baby. Five trials further limited participants to women who began labor spontaneously, three mixed women being induced with women beginning labor spontaneously, and in one, all women were induced. Analgesia protocols varied, but all epidural regimens were of modern, low-dose epidurals. So far, so good.

Examining the individual trials, though, we see a major problem. You would think that the reviewers would have rejected trials that failed to divide participants into distinct groups, one having epidural initiation in early labor and the other in more advanced labor, since the point of the review is to determine whether early or late initiation makes a difference. You would think wrong. Of the nine included trials, six failed to do this.

cc photo bryanrmason http://flickr.com/photos/b-may/397189835

cc photo bryanrmason http://flickr.com/photos/b-may/397189835

The two Chestnut trials (1994a; 1994b) had the same design, differing only in that one was of women who were laboring spontaneously at trial entry and the other included women receiving oxytocin for induction or augmentation. Women were admitted to the trial if they were dilated between 3 and 5 cm. Women in the early group got their epidural immediately while women in the late group could have an epidural only if they were dilated to 5 cm or more. If late-group women were not dilated to 5 cm, they were given systemic opioids and could have a second dose of opioid one hour later. They could have an epidural when they attained 5 cm dilation or regardless of dilation, an hour after the second opioid dose. Let’s see how that worked out.

Among the 149 women in the trial that included women receiving oxytocin (Chestnut 1994b), median dilation in the early group at time of epidural initiation was 3.5 cm, meaning that half the women were dilated more and half less than this amount. The interquartile deviation was 0.5 cm, which means that values were fairly tightly clustered around the median. The authors state, however, that cervical dilation was assessed using 0.5 increments which meant that dilation of 3-4 cm was recorded as 3.5. In other words, women in the early group might have been dilated to as much as 4 cm. The median dilation in the late group was 5.0 cm, again with a 0.5 cm interquartile deviation. Some women in the late group, therefore, were not yet dilated to 5 cm when their epidural began, and, in fact, the authors report that 26 of the 75 women (35%) in the late group were given their epidural after the second dose of opioid but before attaining 5 cm dilation. The small interquartile deviation in the late group tells us that few, if any, women would have been dilated much more than 5 cm. Add in that assessing dilation isn’t exact, so women might have been a bit more or less dilated than they were thought to be, and it becomes clear that the “early” and “late” groups must have overlapped considerably. Furthermore, pretty much all of them were dilated between 3 and 5 cm when they got their epidurals, which means that few of these first-time mothers would have been in active labor, as defined by the new ACOG standards.

Overlap between early and late groups must have been even greater in Chestnut et al.’s (1994a) trial of 334 women laboring spontaneously at trial entry because median dilation in the early group was greater than in the other trial (4 cm, rather than 3.5) while median dilation in the late group was the same (5.0 cm), and interquartile deviation was even tighter in the late group (0.25 cm, rather than 0.5 cm). As before, dilation was measured in 0.5 cm increments, which presumably means that women in the early group dilated to 4-5 cm would have been recorded as “4.5,” thereby qualifying them for the “early” group even though they might have been as much as 5 cm dilated.

Based on my analysis, I would argue that there was no clinically meaningful difference in dilation between early and late groups in either trial.

A second pair of trials, one a mixed trial of spontaneous labor onset and induction and the other all induced, also had the same design in both trials (Wong 2005; Wong 2009). All women were less than 4 cm dilated at first request for pain medication. In the early group, women had an opioid injected intrathecally, i.e. the “spinal” part of a combined spinal-epidural, and an epidural catheter was set. At the second request, an epidural was initiated. In the late group, women were given a systemic opioid. At second request, they were given a second dose of systemic opioid if they hadn’t reached 4 cm dilation and an epidural if they had dilated to 4 cm or more. At third request, they were given an epidural regardless of dilation. Women who had no vaginal exam at second request and were given an epidural were “assumed,” in the authors’ words, to be dilated to at least 4 cm. What were the results?

Wong (2005) included 728 women, some beginning labor spontaneously and some induced. You may already have noticed the flaw in the trials’ design: Wong and colleagues confused the issue by considering intrathecal opioid to be equivalent to epidural anesthetic in the early group, although women didn’t actually receive anesthetic until their second request for pain medication some unknown time later. So far as I know we have no evidence that opiods, spinal or epidural, have any effect on labor progress. As to dilation at the time of epidural initiation, 63% of women in the so-called “early” group were either determined or assumed to be at 4 cm dilation or more while in the late group, some unknown proportion were less than 4 cm dilated either because they got their epidural at third pain medication request regardless of dilation or they were assumed to be at 4 or more cm dilation at second request, but weren’t assessed.

Wong (2009), a study of 806 induced women, was set up the same way but reported data somewhat differently. Early-group women were administered a spinal opioid at a median of 2 cm dilation and an interquartile range of 1.5 to 3 cm, which means that values in the middle 50% of the dataset ranged from 1.5 to 3 cm. We have no information on dilation at the time they received their epidural. The median dilation at which late-group women had their epidural initiated was 4 cm with an interquartile range of 3 to 4 cm, that is, in the middle 50% of the dataset ranged from 3 to 4 cm dilation.

As with the Chestnut trials, dilation at time of epidural initiation in the two Wong trials must have overlapped considerably between groups. And, again, few women in the late epidural group would have been in active labor. The Wong trials, however, muddy the waters even further by considering spinal opioid to be the same thing as epidural anesthetic, and while the authors were careful to use the term “neuraxial analgesia,” the Cochrane reviewers made no such distinction.

This brings us to Parameswara (2012), a trial of 120 women that included both spontaneous onset and induced labors. This trial defined the early group as women less than 2 cm dilated at time of epidural initiation and the late group as women more than 2 cm dilated. That’s all the information they provide on group allocation.

Last of the six, we have Wang (2011), a trial of 60 women in spontaneous labor. All women were given intrathecal anesthetic plus opioid. The early group was started on epidural anesthetic plus opioid 20 minutes later whereas the late group had their epidural initiated when they requested additional pain relief. No information is given on dilation at time of epidural initiation. Not only do we have no idea whether early and late groups differed from one another, women in both groups received neuraxial anesthetic at the same time.

In summary, “garbage in, garbage out.” No conclusions can be drawn about the effect of early versus late epidural administration from these six studies.

The other three studies are a different story. They achieve a reasonable separation between groups. Luxman (1998) studied 60 women with spontaneous labor onset. The early group had a mean, i.e., average, dilation of 2.3 cm with a standard deviation of + or – 0.6 cm while the late group had a mean dilation of 4.5 cm + or – 0.2 cm. Ohel (2006) studied a mixed spontaneous onset and induced group of 449 women. The mean dilation at initiation in the early group was 2.4 cm with a standard deviation of 0.7 cm, and the late group had a mean dilation of 4.6 cm with a standard deviation of 1.1 cm. Wang (2009), the behemoth of the trials, included 12,629 women who began labor spontaneously. The early epidural group had a median dilation of 1.6 cm with an interquartile range of 1.1 to 2.8 and the late group a median of 5.1 cm dilation with an interquartile range of 4.2 to 5.7. Cesarean and instrumental delivery rates were similar between early and late groups in all three trials, so had reviewers included only these three trials, they would still have arrived at the same conclusion: early epidural initiation doesn’t increase likelihood of cesarean and instrumental delivery.

We’re not done, though. Wang (2009) points us to a second, even bigger issue.

The Wang (2009) trial, as did all of the trials, limited participants to healthy first-time mothers with no factors that would predispose them to need a cesarean. The Wang trial further excluded women who didn’t begin labor spontaneously. Nevertheless, the cesarean rate in these ultra-low-risk women was an astonishing 23%. Comparing the trials side-by-side reveals wildly varying cesarean and instrumental vaginal delivery rates in what are essentially homogeneous populations.

© Henci Goer

© Henci Goer

© Henci Goer

© Henci Goer

Comparing the trials uncovers that epidural timing doesn’t matter because any effect will be swamped by the much stronger effect of practice variation.

Analysis of the trials teaches us two lessons: First, systematic reviews can’t always be taken at face value because results depend on the beliefs and biases that the reviewers bring to the table. In this case, they blinded reviewers from seeing that two-thirds of the trials they included weren’t measuring two groups of women, one in early- and one in active-phase labor. Second, practice variation can be an unacknowledged and potent confounding factor for any outcome that depends on care provider judgment.

Conclusion

So what’s our take home? Women need to know that with a judicious care provider who strives for spontaneous vaginal birth whenever possible, early epidural administration won’t increase odds of cesarean or instrumental delivery. With an injudicious one, late initiation won’t decrease them. That being said, there are other reasons to delay an epidural. Maternal fever is associated with epidural duration. Running a fever in a slowly progressing labor could tip the balance toward cesarean delivery as well as have consequences for the baby such as keeping the baby in the nursery for observation, testing for infection, or administering prophylactic IV antibiotics. Then too, a woman just might find she can do very well without one. Epidurals can have adverse effects, some of them serious. Comfort measures, cognitive strategies, and all around good emotionally and physically supportive care don’t. Hospitals, therefore, should make available and encourage use of a wide range of non-pharmacologic alternatives and refrain from routine practices that increase discomfort and hinder women from making use of them. Only then can women truly make a free choice about whether and when to have an epidural.

After reading Henci’s review and the study, what information do you feel is important for women to be aware of regarding epidural use in labor?  What will you say when asked about the study and timing of an epidural?  You may want to reference a previous Science & Sensibility article by Andrea Lythgoe, LCCE, on the use of the peanut ball to promote labor progress when a woman has an epidural. – SM 

References

Caughey, A. B., Cahill, A. G., Guise, J. M., & Rouse, D. J. (2014). Safe prevention of the primary cesarean delivery. American journal of obstetrics and gynecology210(3), 179-193.

Chestnut, D. H., McGrath, J. M., Vincent, R. D., Jr., Penning, D. H., Choi, W. W., Bates, J. N., & McFarlane, C. (1994a). Does early administration of epidural analgesia affect obstetric outcome in nulliparous women who are in spontaneous labor? Anesthesiology, 80(6), 1201-1208. http://www.ncbi.nlm.nih.gov/pubmed/8010466?dopt=Citation

Chestnut, D. H., Vincent, R. D., Jr., McGrath, J. M., Choi, W. W., & Bates, J. N. (1994b). Does early administration of epidural analgesia affect obstetric outcome in nulliparous women who are receiving intravenous oxytocin? Anesthesiology, 80(6), 1193-1200. http://www.ncbi.nlm.nih.gov/pubmed/8010465?dopt=Citation

Lieberman, E., Lang, J. M., Cohen, A., D’Agostino, R., Jr., Datta, S., & Frigoletto, F. D., Jr. (1996). Association of epidural analgesia with cesarean delivery in nulliparas. Obstet Gynecol, 88(6), 993-1000. http://www.ncbi.nlm.nih.gov/pubmed/8942841

Luxman, D., Wolman, I., Groutz, A., Cohen, J. R., Lottan, M., Pauzner, D., & David, M. P. (1998). The effect of early epidural block administration on the progression and outcome of labor. Int J Obstet Anesth, 7(3), 161-164. http://www.ncbi.nlm.nih.gov/pubmed/15321209?dopt=Citation

Nageotte, M. P., Larson, D., Rumney, P. J., Sidhu, M., & Hollenbach, K. (1997). Epidural analgesia compared with combined spinal-epidural analgesia during labor in nulliparous women. N Engl J Med, 337(24), 1715-1719. http://www.ncbi.nlm.nih.gov/pubmed/9392696?dopt=Citation

Ohel, G., Gonen, R., Vaida, S., Barak, S., & Gaitini, L. (2006). Early versus late initiation of epidural analgesia in labor: does it increase the risk of cesarean section? A randomized trial. Am J Obstet Gynecol, 194(3), 600-605. http://www.ncbi.nlm.nih.gov/pubmed/16522386?dopt=Citation

Parameswara, G., Kshama, K., Murthy, H. K., Jalaja, K., Venkat, S. (2012). Early epidural labour analgesia: Does it increase the chances of operative delivery? British Journal of Anaesthesia 108(Suppl 2):ii213–ii214. Note: This is an abstract only so all data from it come from the Cochrane review.

Sng, B. L., Leong, W. L., Zeng, Y., Siddiqui, F. J., Assam, P. N., Lim, Y., . . . Sia, A. T. (2014). Early versus late initiation of epidural analgesia for labour. Cochrane Database Syst Rev, 10, CD007238. doi: 10.1002/14651858.CD007238.pub2 http://www.ncbi.nlm.nih.gov/pubmed/25300169

Thorp, J. A., Eckert, L. O., Ang, M. S., Johnston, D. A., Peaceman, A. M., & Parisi, V. M. (1991). Epidural analgesia and cesarean section for dystocia: risk factors in nulliparas. Am J Perinatol, 8(6), 402-410. http://www.ncbi.nlm.nih.gov/pubmed/1814306?dopt=Citation

Wang, F., Shen, X., Guo, X., Peng, Y., & Gu, X. (2009). Epidural analgesia in the latent phase of labor and the risk of cesarean delivery: a five-year randomized controlled trial. Anesthesiology, 111(4), 871-880. http://www.ncbi.nlm.nih.gov/pubmed/19741492?dopt=Citation

Wang, L. Z., Chang, X. Y., Hu, X. X., Tang, B. L., & Xia, F. (2011). The effect on maternal temperature of delaying initiation of the epidural component of combined spinal-epidural analgesia for labor: a pilot study. Int J Obstet Anesth, 20(4), 312-317. http://www.ncbi.nlm.nih.gov/pubmed/21840705

Wong, C. A., McCarthy, R. J., Sullivan, J. T., Scavone, B. M., Gerber, S. E., & Yaghmour, E. A. (2009). Early compared with late neuraxial analgesia in nulliparous labor induction: a randomized controlled trial. Obstet Gynecol, 113(5), 1066-1074. http://www.ncbi.nlm.nih.gov/pubmed/19384122?dopt=Citation

Wong, C. A., Scavone, B. M., Peaceman, A. M., McCarthy, R. J., Sullivan, J. T., Diaz, N. T., . . . Grouper, S. (2005). The risk of cesarean delivery with neuraxial analgesia given early versus late in labor. N Engl J Med, 352(7), 655-665. http://www.ncbi.nlm.nih.gov/pubmed/15716559?dopt=Citation

About Henci Goer

Henci Goer

Henci Goer

Henci Goer, award-winning medical writer and internationally known speaker, is the author of The Thinking Woman’s Guide to a Better Birth and Optimal Care in Childbirth: The Case for a Physiologic Approach She is the winner of the American College of Nurse-Midwives “Best Book of the Year” award. An independent scholar, she is an acknowledged expert on evidence-based maternity care.  

Cesarean Birth, Childbirth Education, Epidural Analgesia, Guest Posts, informed Consent, Medical Interventions, New Research, Systematic Review , , , , , , ,

The Complete Illustrated Birthing Companion: A Book Review

September 10th, 2013 by avatar

I recently had the opportunity to review a book published in January, 2013, written for birthing families. The Complete Illustrated Birthing Companion; A Step-by-Step Guide to Creating the Best Birthing Plan for a Safe, Less Painful, and Successful Delivery for You and Your Baby.  This book is authored by a diverse team of experts, Amanda French, M.D., an OB/Gyn, Susan Thomforde, CNM, Jeanne Faulkner, RN and Dana Rousmaniere, author of pregnancy and birth topics. I wanted to share my review with Science & Sensibility readers so you can consider if you want to add this book to your recommended reading list for expecting families. The book is available on Amazon for 14.29 and a Kindle version is available as well.

This book is marketed as a large 8 1/2 by 11 inch paperback with an attractive cover.  Inside is easy to read print, a pleasant amount of white space on semi-glossy paper, along with full color photographs and illustrations.  There are some beautiful photographs in there, clearly taken by talented photographers, but some of the photos seemed too unnatural, women posed in the perfect position, wearing make-up with hair just so.  The pictures are all completely modest, with the exception of just one woman in a birth tub, which surprised me in a book about birth.  In my experience, birth is a bit more “gritty” than represented by the pictures chosen for this book.  I really appreciated the diversity of images of the women and their families, women of color and their families are well represented throughout. I also appreciated the choice of language, women have partners and those partners can be men or women.

Who is this book for?

This book for is for women who are still deciding on a birth along the spectrum of options, from a home birth to a planned cesarean. It also makes sense for women who are not quite sure what type of birth they want; they can read about all the choices as they settle on what feels good to themselves and their families.  The book is written in easy to understand language, and when medical vocabulary is introduced, a definition is provided so that readers can be clearly understand what is being discussed.  The book is best used for determining what type of birth a woman is interested in having.  If the mother has already determined where and how she would like to birth,  then this book, which is in large part a comparison of the different options, would be less useful.

Jeanne Faulkner, RN

What will families find inside?

The book starts off by asking women to imagine their perfect birth, encouraging them to hold this in their minds, but to also remember that birth requires flexibility as things can change during a pregnancy or labor that will require a deviation from what a mother was planning.  A brief but accurate overview of provider types (and a good list of questions to ask providers to determine who is right for each mother) and childbirth education options are covered, and states Lamaze includes a “good, comprehensive overview of childbirth.”  The chapters are then divided into options by birth location as well as pain medication choices, and then goes on to cover induction, planned and unplanned cesarean. Natural coping techniques and pharmacological pain medication options are covered in a chapter toward the end, along with a guideline for writing a birth plan.

“Unmedicated Vaginal Birth at Home” or “Epidural, Vaginal Birth in the Hospital” are some of the chapter titles and for each section the authors take the time to explain what this option is, why it may or may not be right for any particular woman (in the case of home birth, why a woman  might risk out of this option prenatally or in labor), the pros and cons of each option and how to best prepare if this is the choice a woman has made.  Throughout the book, the authors take care to state that women should be flexible and things may change. Desiring an epidural but not having time for one is a possibility that women need to consider.  I really appreciate this gentle reminder throughout the book, as I too believe that being flexible and being able to deviate from what a woman originally planned will help as the labor unfolds.

For each type of birth, women are given suggestions to help them achieve the birth they want and are encouraged to have a variety of coping techniques lined up for dealing with labor pain if they are choosing to go unmedicated.  Realistic and useful advice is given, even when the birth is highly managed, so that the mother and her partner can have a positive experience.

Amanda French, M.D.

What families won’t find inside?

This is not a book about pregnancy, breastfeeding, postpartum care or newborn care and it doesn’t claim to be.  This is a book about birth and the choices surrounding birth.  Families who want to read about prenatal testing, or learn about breastfeeding techniques will want to have other books in their collection that cover those topics.  While this book does a nice job covering the different options, birth locations and provider choices available to them,  it does so in a very matter of fact way.  There is not a lot of “rah-rah you can do it” language or encouragement for women to stretch for a low intervention option.  On one hand, it is nice to have the facts. On the other hand, evidence shows that for normal, low risk women, the less interventions the better for both mother and baby.  I am not sure that parents will walk away with that message after reading this book.

Would I recommend this book?

While providing a nice general overview of birth choices, I felt like there were several times that the authors wrote that women should trust their care provider’s expert recommendations versus becoming more informed and discussing all options, including the right to informed refusal.

For example, in the small section on episiotomy, it reads “How do I decide whether I want an episiotomy or a tear?  The short answer is this: You don’t make that decision, your provider does…If your provider decides an episiotomy is absolutely necessary, for example, to get the baby out more quickly, then so be it.  Your provider makes that decision based on the medical situation at hand.”  No mention of informing the woman, seeking consent or alternatives to cutting, for example changing position or waiting.

One of the authors, Dr. Amanda French also states several times that she stands with ACOG’s statement on homebirth (which is that birth should occur in a hospital or birth center attached to a hospital) and does not believe that having a baby at home is safe. She does acknowledge a woman’s right to make the decision on birth location for herself.  In reading the chapter on home birth, this bias does come through.

Dana Rousmaniere

In my opinion, the book is written through the health care provider’s lens.  Doulas are promoted- but readers are warned to watch out for those doulas who may have a “strong personal agenda” and parents are encouraged to work with experienced doulas, instead of doulas-in-training or those just starting out.  Birthing women are asked to let the anesthesiologist attempt two epidural placements, (if the first one does not work due to the mother having a “challenging back” or “not being in the ideal position”) before asking for another doctor to try.  Women are told to follow the recommendations of health staff in several places in the book.  Families are told that their newborn will have antibiotic eye ointment and hepatitis B vaccines administered.

In the chapter on VBACs, women are told that a con of VBAC-ing is that ”Vaginal delivery can result in tears in the vagina, which can be repaired immediately after delivery but may result in pain for several weeks after birth.”  Isn’t this a risk of any vaginal delivery?  For the families that I work with, I try to have mothers (and their partners) view themselves as a more equal partner in the decisions that are being made during labor and birth.

In summary

Overall, this book does a fair job of representing what to expect in eight different labor and birth scenarios, who might be a good candidate for each option and how best to be prepared.  Women can read and get assistance in choosing what might be the best option for them. Information on coping techniques and even pictures of good labor positions to try are well organized for easy reference.  For a woman who is undecided about where she wants to birth, this book will help her to understand the differences and the pros and cons of each location and type of birth, along with who attends births in each location.  For women who are have more clarity on what type of birth they want, I might make a different birth book recommendation.

Have you read this book?  Can you share your thoughts and opinion in our comments section?

 

Book Reviews, Epidural Analgesia, Home Birth, informed Consent, Maternity Care, Medical Interventions, Midwifery, Pain Management, Vaginal Birth After Cesarean (VBAC) , , , , , , , , , , , ,

Does Epidural Analgesia Predispose to Persistent Occiput Posterior?

February 14th, 2013 by avatar

Photo by Patti Ramos Photography

In my January Science and Sensibility blog post, I answered the question “Can We Prevent Persistent Occiput Posterior?” but because it wasn’t relevant to the study that prompted the post, and the piece was already long, I didn’t look at the role of epidural analgesia. Let me now rectify that.

All five studies examining the relationship between epidural analgesia and persistent occiput posterior (OP) find an association between them. Three studies compared women with an epidural versus no epidural according to whether they had an OP baby at delivery and found that 4 to 10 more women per 100 having an epidural had an OP baby at delivery (Cheng, 2006; Lieberman, 2005; Sizer, 2000). The other two compared women with an OP baby at delivery according to whether they had an epidural and found that 13 and 27 more women per 100 with a persistent OP baby had an epidural (Fitzpatrick, 2001; Ponkey, 2003).

Their results, however, aren’t sufficient to convict epidurals because we can’t tell whether having an epidural led to persistent OP or more painful and prolonged OP labor led to having an epidural. Investigators in one of the five studies argued for OP labor coming first on the grounds that while epidurals were more common in women with an OP baby at delivery than in women with an OA baby at delivery (74% vs. 47%) at their institution, a rise in epidural use from 3% in 1975 to 47% in 1998 had, if anything, decreased the hospital’s overall rate of persistent OP (4% vs. 2%) (Fitzpatrick, 2001). This must mean that as epidurals became more freely available, women having difficult OP labors were more likely to opt for one. Epidurals were the result, not the cause, of persistent OP. On the other hand, we have some corroborating evidence for their guilt. For one thing, back pain is thought to be a major reason why women with OP babies are more likely to want epidurals, but it turns out that back pain isn’t unique to OP. Serial sonograms reveal that virtually identical percentages of women laboring with an OA baby report back pain (Lieberman, 2005). For another, three of the five studies took into account other factors associated with difficult labor such as labor induction, labor augmentation, and birth weight and still found that epidurals were an independent risk factor for persistent OP (Cheng, 2006; Lieberman, 2005; Sizer, 2000).

Nevertheless, evidence from observational studies isn’t strong enough to close the case. As I noted, observational studies can determine association but not causation. In addition, investigators may not be able to identify all the confounding and correlating factors that affect outcomes. For a more definitive answer, we need experimental studies. This brings us to randomized controlled trials (RCTs), in which participants are randomly allocated to one form of treatment or the other, and to meta-analysis of RCTs, in which statistical techniques are used to pool data from more than one trial.

The Cochrane systematic review of epidural versus no epidural in labor pools data from four RCTs (673 women overall) that reported on persistent OP (Anim-Somuah, 2011). Five more women per 100 assigned to the epidural group had a persistent OP baby, but meta-analysis found that the difference just missed achieving statistical significance. The risk ratio was 1.4, meaning a 40% increased risk of persistent OP in women assigned to the epidural group compared with women assigned to the no-epidural group, but the 95% confidence interval ranged from 1.0 to 2.0, meaning a 95% probability that the true value lies between no increase (ratio of 1:1) and double the risk (2.0). However, a problem with the RCTs of epidural versus no epidural is that substantial percentages of women assigned to the no-epidural group actually had epidurals, but, as is prescribed in RCT data analysis, they were kept in their original group. In two of the four trials (204 women), though, 10% or less of women assigned to the no-epidural group had epidurals. If we calculate the excess rate of persistent OP in these two trials, we find that the gap widens to 9 more women per 100 with epidurals having a persistent OP baby. We don’t know whether this difference would achieve statistical significance, but the fact that the excess is in the same range as reported in the observational studies (4 to 10 more per 100) gives confidence in its validity.

Patti Ramos Photography

We also have two studies that suggest that the timing of the epidural may matter. One, of 320 women, reports that, after controlling for age, induction of labor, and birth weight, initiating an epidural at fetal station less than zero (above the ischial spines) resulted in 16 more women having a persistent OP or occiput transverse (OT) baby compared with initiation at 0 station or greater (at or lower than the ischial spines), an excess that rose to 20 more per 100 in first time mothers (Robinson, 1996). The other study analyzed outcomes in 500 first-time mothers according to whether an epidural was administered early (at or before 5 cm dilation), late (after 5 cm dilation), or not at all (Thorp, 1991). Seventeen more women per 100 in the early group had a persistent OP or OT baby compared with women in the late-epidural group, and 12 more had a persistent OP or OT baby compared with the no-epidural group, but rates were similar in women in the late and no epidural groups.

Taken all together, we may not have absolute proof of epidural culpability in predisposing to OP, but if I were on the jury, I would vote them “guilty as charged.”

Take home: Even without certainty, the precautionary principle dictates recommending to women desiring an epidural that they use other measures to cope with labor pain until they enter active labor and until it seems clear that positioning and activities are not putting a slow labor on track.

What do you tell your clients, students and patients about the impact on fetal positioning in labor and birth?  Will having this information change what you say?  Let us know in the comments section.

References

Anim-Somuah, M., Smyth, R. M., & Jones, L. (2011). Epidural versus non-epidural or no analgesia in labour. Cochrane Database of Systematic Reviews(12), CD000331.

Cheng, Y. W., Shaffer, B. L., & Caughey, A. B. (2006). Associated factors and outcomes of persistent occiput posterior position: A retrospective cohort study from 1976 to 2001. Journal of Maternal Fetal and Neonatal Medicine, 19(9), 563-568.

Fitzpatrick, M., McQuillan, K., & O’Herlihy, C. (2001). Influence of persistent occiput posterior position on delivery outcome. Obstetrics and Gynecology, 98(6), 1027-1031.

Lieberman, E., Davidson, K., Lee-Parritz, A., & Shearer, E. (2005). Changes in fetal position during labor and their association with epidural analgesia. Obstetrics and Gynecology, 105(5 Pt 1), 974-982.

Ponkey, S. E., Cohen, A. P., Heffner, L. J., & Lieberman, E. (2003). Persistent fetal occiput posterior position: obstetric outcomes. Obstetrics and Gynecology, 101(5 Pt 1), 915-920. 

Robinson, C. A., Macones, G. A., Roth, N. W., & Morgan, M. A. (1996). Does station of the fetal head at epidural placement affect the position of the fetal vertex at delivery? American Journal of Obstetrics and Gynecology, 175(4 Pt 1), 991-994.

Sizer, A. R., & Nirmal, D. M. (2000). Occipitoposterior position: associated factors and obstetric outcome in nulliparas. Obstetrics and Gynecology, 96(5 Pt 1), 749-752.

Thorp, J. A., Eckert, L. O., Ang, M. S., Johnston, D. A., Peaceman, A. M., & Parisi, V. M. (1991). Epidural analgesia and cesarean section for dystocia: risk factors in nulliparas. American Journal of Perinatology, 8(6), 402-410.

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