24h-payday

Archive

Posts Tagged ‘cesareans’

Epidurals: Do They or Don’t They Increase Cesareans?

January 27th, 2015 by avatar

By Henci Goer

In October, Author Henci Goer wrote an article for Science & Sensibility, Epidural Anesthesia: To Delay or Not To Delay – That is the Question – examining the impact of the timing of an epidural on labor and birth.  Today Henci looks at some new research, Epidural analgesia in labour and risk of caesarean delivery which seeks to determine whether receiving an epidural at all impacts the likelihood of a cesarean delivery.  Lamaze International has a great infographic on epidurals that you also may find very helpful. – Sharon Muza, Community Manager, Science & Sensibility.

© J. Wasikowski, provided by Birthtastic

© J. Wasikowski, provided by Birthtastic

Let’s start with a bit of background for those of you who didn’t personally live through the early controversy over whether epidurals increased the cesarean rate. As epidurals began to achieve popularity in the late 1970s and 1980s, one researcher sounded the alarm when he and his group published a study of 714 first-time mothers showing that even after excluding women with big babies and women whose labor pattern was abnormal prior to having an epidural, epidurals remained a potent factor in cesarean rates for delayed progress (Thorp 1989). Everyone pooh-poohed his finding on grounds that observational studies can’t truly determine whether epidurals lead to more cesareans or women experiencing more prolonged, painful labors, and therefore at higher risk for cesarean, were more likely to want epidurals. The “chicken versus egg” question, they argued, couldn’t be resolved without a randomized controlled trial (RCT), and it wasn’t likely that women would agree to be assigned by chance to have an epidural or not. In point of fact, that same year saw publication of a small Danish RCT (107 women, 104 of them first-time mothers) (Philipsen 1989). It reported that having an epidural nearly tripled the cesarean rate (16% vs. 6%) for “cephalopelvic disproportion” despite no clinical evidence of CPD being a requirement for inclusion. The investigators ignored this, however, concluding only that instrumental vaginal delivery rates were similar, and epidurals provided better pain relief. In any case, the anesthetic dose was much higher than was already becoming the norm, so it could be reasonably argued that the trial’s findings wouldn’t apply to modern-day practice.

Thorp, meanwhile, took up the RCT challenge. He and his colleagues carried out an epidural versus no epidural trial in 93 first-time mothers and found that epidurals did, in fact, lead to cesareans (25% vs. 2%), not vice versa (Thorp 1993). That bit of unwelcome news precipitated a stampede to perform more RCTs, and when enough of those had accumulated, to a series of systematic reviews pooling their data (meta-analysis), of which the Cochrane review, Anim-Somuah et al. (2011), is the latest. These reached the more comfortable conclusion that epidurals didn’t increase likelihood of cesarean, and pro-epiduralists breathed a collective sigh of relief and went back, if they had ever stopped, to unreservedly recommending epidurals. (This rather sweeps under the rug the other problems epidurals can cause, but that’s a topic for another day.)

Weaknesses of the “Epidural” vs. “No Epidural” Trials

Epidural

By User:Ravedave (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html)

The finding that epidurals don’t increase cesareans is puzzling because they increase likelihood of factors associated with them (Anim-Somuah 2011). For one thing, they increase use of oxytocin to augment labor, which implies they slow labor. For another, more women run fevers, and it stands to reason that a woman progressing slowly who starts running a fever is a likely candidate for cesarean. For a third, the difference in fetal malposition (occiput posterior) rates at delivery comes close to achieving statistical significance, meaning the difference is unlikely to be due to chance. Persistent OP is strongly associated with cesarean delivery (Cheng 2006; Fitzpatrick 2001; Phipps 2014; Ponkey 2003; Senecal 2005; Sizer 2000). Epidurals even increase cesareans for fetal distress by 40%, although the absolute difference didn’t amount to much (1 more per 100 women). Could a difference exist and meta-analysis of RCTs fail to detect it?

A string of well-conducted observational studies over the years have suggested that they could (Eriksen 2011; Kjaergaard 2008; Lieberman 1996; Nguyen 2010), the most recent of which is a very large, very convincing study published last fall (Bannister-Tyrrell 2014). Its authors point out, as have others before them, the weaknesses of the RCTs, weaknesses serious enough to nullify their results or make them inapplicable to typical community practice (external validity).

To begin with, in most trials, substantial percentages of women allocated to the non-epidural group ended up having epidurals, and some women allocated to the epidural group ended up not having one. Since RCTs analyze results according to group assignment (to do otherwise would negate the point of random assignment, which is to avoid bias), not what actually happened, this diminishes differences between groups. In addition, trials were mostly confined to women with no medical or obstetric complications who were treated according to strict protocols for labor management and indications for cesarean delivery. Neither is the case in most hospitals. To these I would add that many trials lumped together first-time mothers and women with prior births when reporting outcomes. First-time mothers are much more susceptible to factors that impede progress, so including women with prior vaginal births can make it appear that epidurals are less problematic for first-time mothers than they really are. In addition, three of the trials were carried out in a hospital where participants were mostly attended by midwives, and cesarean rates were much lower than is common for women attended by obstetricians.

All of this means that any null results in meta-analyses of the trials can be taken with a grain of salt, any findings of significant differences probably represent a minimal value, and first-time moms may be harder hit than appears. To cite one example, Anim-Somuah (2011) reported that 5 more women per 100 having epidurals had a malpositioned baby at delivery (18% vs. 13%) in the 4 trials reporting this outcome, a difference, as I said, that just missed achieving statistical significance. But when I confined results to the two trials in first-time mothers alone in which 10% or fewer of the women in the “no-epidural” group had an epidural, the gap widened to 9 more per 100 (11% vs. 2%).

Summary of the Bannister-Tyrrell (2014) Analysis

Bannister-Tyrrell and colleagues (2014) drew their population from a database of 210,700 Australian women with no prior cesareans who were laboring at term with a singleton, head-down baby. A strength of the database was that, unlike most, it distinguished epidurals for labor from epidurals for delivery. Using a long list of factors, investigators constructed a propensity score for how likely a woman was to have an epidural, matched women according to their score, and compared results according to whether women with the same score had or didn’t have an epidural. Matched controls were found for 52,600 women who had an epidural and were found across the full range of propensity scores. Women having epidurals were 2.5 times more likely to have a cesarean (20% vs. 8%), or put another way, 12 more women per 100 having epidurals had a cesarean (absolute excess), which amounts to 1 additional cesarean for every 8.5 women having an epidural (number needed to harm). Among first-time mothers, women having epidurals were 2.4 times more likely to have a cesarean. Study authors didn’t provide cesarean rates for this subgroup, but the raw cesarean rates overall were 18% in first-time mothers versus 2% in women with prior births, so the effect on this more vulnerable population could be dire.

But there’s still more. Investigators further adjusted for confounding factors not captured in their database. These included differences in health-care settings (same state but not same city), care provider (women without epidurals are more likely to be attended by midwives), and for confounding interventions more likely with epidurals (continuous fetal monitoring). Relative risk of cesarean with an epidural remained at 2.5. Investigators then adjusted for the association between occiput posterior baby and cesarean by setting estimates of the risk ratio to exceed the strongest associations reported in the literature, and they assumed that the prevalence of severe labor pain was 3 to 4 times higher in women having epidurals. Factoring these into their statistical analysis reduced the risk ratio, but women having epidurals still were 50% more likely to have a cesarean. This means that with a baseline cesarean rate of 8% in women without an epidural, 12% of women with an epidural will have one or 4 more women per 100 or 1 more cesarean for every 25 women.

The Take-Home

At the very least we cannot assure women with confidence that epidurals don’t increase the likelihood of cesarean. For this reason and because of their numerous other drawbacks and considering that comfort measures and other strategies have been shown to be both effective for most women and free of adverse effects (Declercq 2006; Jones 2012), women may want to make epidurals Plan B rather than Plan A. That being said, whatever their choice, women can minimize their chance of cesarean—with or without an epidural—by choosing a midwife or doctor whose policies and practices promote spontaneous vaginal birth http://www.lamaze.org/HealthyBirthPractices.

References

Anim-Somuah, M., Smyth, R. M., & Jones, L. (2011). Epidural versus non-epidural or no analgesia in labour. Cochrane Database Syst Rev(12), CD000331. doi: 10.1002/14651858.CD000331.pub3 http://www.ncbi.nlm.nih.gov/pubmed/22161362

Bannister-Tyrrell, M., Ford, J. B., Morris, J. M., & Roberts, C. L. (2014). Epidural analgesia in labour and risk of caesarean delivery. Paediatr Perinat Epidemiol, 28(5), 400-411. http://www.ncbi.nlm.nih.gov/pubmed/25040829

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. J Matern Fetal Neonatal Med, 19(9), 563-568. http://www.ncbi.nlm.nih.gov/pubmed/16966125?dopt=Citation

Declercq, E., Sakala, C., Corry, M. P., & Applebaum, S. (2006). Listening to Mothers II: Report of the Second National U.S. Survey of Women’s Childbearing Experiences. New York: Childbirth Connection. http://childbirthconnection.org/pdfs/LTMII_report.pdf

Eriksen, L. M., Nohr, E. A., & Kjaergaard, H. (2011). Mode of delivery after epidural analgesia in a cohort of low-risk nulliparas. Birth, 38(4), 317-326. http://www.ncbi.nlm.nih.gov/pubmed/22112332

Fitzpatrick, M., McQuillan, K., & O’Herlihy, C. (2001). Influence of persistent occiput posterior position on delivery outcome. Obstet Gynecol, 98(6), 1027-1031. http://www.ncbi.nlm.nih.gov/pubmed/11755548?dopt=Citation

Jones, L., Othman, M., Dowswell, T., Alfirevic, Z., Gates, S., Newburn, M., . . . Neilson, J. P. (2012). Pain management for women in labour: an overview of systematic reviews. Cochrane Database Syst Rev, 3, CD009234. http://www.ncbi.nlm.nih.gov/pubmed/22419342

Kjaergaard, H., Olsen, J., Ottesen, B., Nyberg, P., & Dykes, A. K. (2008). Obstetric risk indicators for labour dystocia in nulliparous women: a multi-centre cohort study. BMC Pregnancy Childbirth, 8, 45. http://www.ncbi.nlm.nih.gov/pubmed/18837972?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

Nguyen, U. S., Rothman, K. J., Demissie, S., Jackson, D. J., Lang, J. M., & Ecker, J. L. (2010). Epidural analgesia and risks of cesarean and operative vaginal deliveries in nulliparous and multiparous women. Matern Child Health J, 14(5), 705-712. http://www.ncbi.nlm.nih.gov/pubmed/19760498?dopt=Citation

Philipsen, T., & Jensen, N. H. (1989). Epidural block or parenteral pethidine as analgesic in labour; a randomized study concerning progress in labour and instrumental deliveries. Eur J Obstet Gynecol Reprod Biol, 30(1), 27-33. http://www.ncbi.nlm.nih.gov/pubmed/2924990

Phipps, H., Hyett, J. A., Graham, K., Carseldine, W. J., Tooher, J., & de Vries, B. (2014). Is there an association between sonographically determined occipito-transverse position in the second stage of labor and operative delivery? Acta Obstet Gynecol Scand, 93(10), 1018-1024. http://www.ncbi.nlm.nih.gov/pubmed/25060716

Ponkey, S. E., Cohen, A. P., Heffner, L. J., & Lieberman, E. (2003). Persistent fetal occiput posterior position: obstetric outcomes. Obstet Gynecol, 101(5 Pt 1), 915-920. http://www.ncbi.nlm.nih.gov/pubmed/12738150?dopt=Citation

Senecal, J., Xiong, X., Fraser, W. D., & Pushing Early Or Pushing Late with Epidural study, group. (2005). Effect of fetal position on second-stage duration and labor outcome. Obstet Gynecol, 105(4), 763-772. http://www.ncbi.nlm.nih.gov/pubmed/15802403

Sizer, A. R., & Nirmal, D. M. (2000). Occipitoposterior position: associated factors and obstetric outcome in nulliparas. Obstet Gynecol, 96(5 Pt 1), 749-752. http://www.ncbi.nlm.nih.gov/pubmed/11042312?dopt=Citation

Thorp, J. A., Hu, D. H., Albin, R. M., McNitt, J., Meyer, B. A., Cohen, G. R., & Yeast, J. D. (1993). The effect of intrapartum epidural analgesia on nulliparous labor: a randomized, controlled, prospective trial. Am J Obstet Gynecol, 169(4), 851-858. http://www.ncbi.nlm.nih.gov/pubmed/8238138?dopt=Citation

Thorp, J. A., Parisi, V. M., Boylan, P. C., & Johnston, D. A. (1989). The effect of continuous epidural analgesia on cesarean section for dystocia in nulliparous women. Am J Obstet Gynecol, 161(3), 670-675. http://www.ncbi.nlm.nih.gov/pubmed/2782350

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, Healthy Birth Practices, Medical Interventions, New Research, Pain Management, Research , , , , , , ,

Test Your Knowledge of Just Released 2012 Birth Data – A Fun Pop Quiz

January 28th, 2014 by avatar
Image: blog.camera.org
Image: blog.camera.org

As childbirth educators and birth professionals who work with expectant families, it is critical that we remain up to date on the newest data and research available on a wide variety of topics.  When we have current information, we are then able to share this information with the families that we work with in relevant ways.  Today, I would like to bring to your attention to the most fundamental, yet comprehensive data available about birth in the United States.  2012 date was released last month by the Center for Health Statistics.  The National Vital Statistics Report “Births: Final Data for 2012” is a gold mine of information for those of you who are interested in the state of births in the USA.

I thought it would be fun to try and present some of the data in the form of a quiz, for Science & Sensibility readers to take just for kicks.  Take the quiz and see how many of the ten questions you get right?  Then follow the link above to the complete report to find out more details and other interesting facts about birth in the USA in 2012. I invite you to share your score in our comments section along with any surprises you discovered when quizzing yourself.  If you want to see how you did compared to all the other folks who took the test, you can register on the quiz site, but it is totally not necessary.  Take it more than once if you like!  You might even use this technique with your students for a fun class activity.

References:

Martin, J. A., Hamilton, B. E., Ventura, S. J., Osterman, M. J., & Mathews, T. J. (2013). Births: final data for 2011. National Vital Statistics Report62(1).

Disclaimer:

This quiz may not work on mobile devices.

Tips for using with the Safari Browser:

  1. Click on the settings menu and then Preferences… (or CTRL+,)
  2. Click on the Security tab at the top
  3. Check “Enable Javascript”
  4. For “Accept cookies” – select “Always”
  5. Close the preferences window
  6. Close your Safari browser and reopen and play the quiz again

The ads placed at the end of this free quiz application are at the discretion of the software developers

Image sources

Q1: Bonnie U. Gruenberg

Q2: http://www.flickr.com/photos/_nezemnaya_/3843726606/

Q3: http://www.flickr.com/people/kioko/

Q4: multiple-sclerosis-research.blogspot.com

Q5: Krista Guenin/Krista Photography

Q6: en.wikipedia.org

Q7: eyeliam

Q8: http://commons.wikimedia.org/wiki/File:Map_of_USA_with_state_names.svg

Q9: en.wikipedia.org

Q10: www.dailymail.co.uk 

Babies, Cesarean Birth, Childbirth Education, Home Birth, Maternity Care, New Research, Newborns , , , , , , , , ,

Lamaze International Releases Valuable Cesarean Infographic For You To Share!

October 10th, 2013 by avatar

Lamaze International has long been a leader in providing resources for both parents and birth professionals that promote safe and healthy birth for women and babies.  Evidence based information, appealing handouts, useful webinars for both parents and professionals, continuing education opportunities and more can all be found within the Lamaze International structure.  In May, 2012, Lamaze International released  (and later went on to be a co-winner for the 2013 Nonprofit PR Award for Digital PR and Marketing) the Push For Your Baby campaign, which encouraged families to “push for better” and “spot the best care,” providing resources to help parents wade through the overabundance of often inaccurate information swimming past them, and make choices that support a healthy pregnancy, a healthy birth and a healthy mother and baby.

Today, as I make my way to New Orleans, to join other professionals at the 2013 Annual Lamaze International Conference, “Let the Good Times Roll for Safe and Healthy Birth,” Lamaze International is pleased to announce the release of a useful and appealing infographic titled “What’s the Deal with Cesareans?” In the USA today, 1 in 3 mothers will give birth by cesarean section.  While, many cesareans are necessary, others are often a result of interventions performed at the end of pregnancy or during labor for no medical reason.  For many families, easy to understand, accurate information is hard to find and they feel pressure to follow their health care provider’s suggestions, even if it is not evidence based or following best practice guidelines.

Families taking Lamaze classes are learning about the Six Healthy Birth Practices, which can help them to avoid unnecessary interventions. Now, Lamaze childbirth educators and others can share (and post in their classrooms) this attractive infographic that highlights the situation of too many unneeded cesareans in our country.  Parents and educators alike can easily see what the risks of cesarean surgery to mother and baby are, and learn how to reduce the likelihood of having a cesarean in the absence of medical need.

In this infographic, women are encouraged to take Lamaze childbirth classes, work with a doula, select a provider with a low rate of cesarean births, advocate for vaginal birth after cesarean and follow the Six Healthy Care Practices, to set themselves up for the best birth possible.  This infographic clearly states the problem of unneeded cesareans, the risks to mother and baby, and provides do-able actions steps.

It is time for women to become the best advocate possible for their birth and their baby.  With this appealing, useful and informative infographic poster, families can and will make better choices and know to seek out additional information and resources.

Educators and other birth professionals, you can find a high resolution infographic to download and print here.

Send your families to the Lamaze International site for parents, to find the infographic and other useful information on cesarean surgery.

For Lamaze members, log in to our professional site to access this infographic and a whole slew of other useful classroom activities, handouts and information sheets.

I am proud to say that I am a Lamaze Certified Childbirth Educator, and that my organization, Lamaze International, is leading the way in advocating for healthier births for mothers and babies through sources such as the “What’s the Deal with Cesareans?” infographic and other evidence based information and resources.  Thank you Lamaze!

What do you think of this infographic?  How are you going to use it with the families you work with?  Can you think of how you might incorporate this into your childbirth classes or discuss with clients and patients?  Let us know in the comments section, we would love your feedback!  And, see you at the conference!

 

 

Babies, Cesarean Birth, Evidence Based Medicine, Healthy Birth Practices, Healthy Care Practices, informed Consent, Lamaze International, Lamaze International 2013 Annual Conference, Maternal Quality Improvement, Maternity Care, Medical Interventions, Newborns, Patient Advocacy, Push for Your Baby , , , , , , , , ,

Upcoming Free Lamaze International VBAC Webinar for Parents; Monday, September 23rd

September 20th, 2013 by avatar

If you are a birth professional who works with families exploring their VBAC options, then you will want to let them know about this *free* Lamaze International for Parents webinar on this very topic.

Lamaze’s latest webinar will answer some of these pressing questions expecting parents have as they consider VBAC as a viable option for birth. The “Preparing for Vaginal Birth: Pushing Past a Previous Cesarean” webinar will help parents to:

  1. Learn about the latest research findings regarding safety of VBAC
  2. Understand the benefits and risks that come with VBAC
  3. Learn about existing VBAC access issues, and why women have such a hard time finding supportive care providers
  4. Ensure that women have the support they need if they decide VBAC is right for them.

The presenters are Desirre Andrews, CPM, CCCE, CLD, CLE, LCCE and Debbie Petersburg, LCCE, FACCE. Desirre has expertise in the perinatal field as an educator, doula, advocate, trainer, public speaker, blogger and social media enthusiast. She connects with consumers and birth professionals to be encouraged, confident and equipped to positively impact maternal and fetal health on the individual basis and broad spectrum. Debbie currently serves as the Childbirth Educator Training and Resources Chair within the Education Council of Lamaze International. She has been a Trainer for the Duke AHEC Lamaze Seminar program since 2008 helping to facilitate training throughout the southeast as well as Lamaze Annual Conference pre-seminars. She has also taught childbirth education and labor support classes since 1996 at Rex Hospital in Raleigh, North Carolina and serves as the education representative on the hospital’s Patient Satisfaction Committee.

Please share with your clients, students, patients, friends and family who may find this information useful.  They may register here.

To see previously recorded parent webinars available for viewing, click here.

Cesarean Birth, Childbirth Education, Continuing Education, Webinars , , , , , , , ,

Do Cesareans Cause Endometriosis? The Data Accumulate

July 30th, 2013 by avatar

 Today on Science & Sensibility, regular contributor Henci Goer takes a look at a new retrospective study looking at the potential relationship between cesarean birth and endometriosis development in the mother in the years after her surgery.  Did you know that research indicates an increase in endometriosis for those women who have undergone a cesarean delivery?  Henci shares this new study and asks us to continue to look further. – Sharon Muza, Community Manager, Science & Sensibility.

________________________

© Patti Ramos Photography

My very first post in Science & Sensibility back in 2009 was a round-up of case studies and series reporting on the formation of endometriosis—also called “endometrioma” because the cells formed a solid mass—in the cesarean wound. I commented that case studies could serve to draw attention to possible serious complications worthy of further investigation and ended the post with the hope that researchers would take a closer look at this one. Now I have run across a study that does exactly that.  I wanted to share it with you today.

Swedish investigators, Andolf, Thorsell, and Kallen (2010), used a national in-patient data registry linked to a birth registry to identify all women giving birth to their first child between 1986 and 2004. After excluding women who had a diagnosis of endometriosis before their first birth, 709,090 women remained, of whom 3110 were diagnosed with endometriosis and treated in hospitals after their first birth. Investigators tracked women from the date they gave birth to their first child to either the date of the first diagnosis of endometriosis, the date of their 55th birthday, or December 31, 2004, the date on which investigators retrieved the dataset, whichever came first.

Investigators looked both at cesarean-scar endometrioma and general pelvic endometriosis. They postulated that since endometriosis results from uterine lining cells taking hold and growing outside of the uterus, cesarean surgery could disperse these cells throughout the pelvis, not just seed them into the uterine wound.

After accounting for factors that were associated both with endometriosis and cesarean delivery (maternal age at first delivery; BMI; smoking; and years of involuntary childlessness before first delivery), none of which had any appreciable effect, they found that having at least one cesarean nearly doubled the risk of developing endometriosis (hazard ratio: 1.8). This calculated to 1 additional case of endometriosis within 10 years for every 325 women undergoing cesarean surgery. Having multiple cesareans didn’t appear to further increase the risk. Both women with only vaginal births and women with cesareans had new diagnoses of endometriosis, but a graph of the cumulative incidence rates showed that the line angled upward much more steeply as time passed in women with cesareans compared with women with only vaginal births.

The incidence rate of cesarean-scar endometrioma specifically was 1 per 1000 among women having cesareans. This may be considered a minimum since the data registry would not capture women who had cesarean-scar endometrioma but who either never received the correct diagnosis or were never admitted to a hospital for treatment.

The Swedish analysis has added to our knowledge of the relationship between cesarean surgery and endometriosis. It gave us an incidence rate for cesarean-scar endometrioma and showed that cesarean surgery also is associated with increased likelihood of developing generalized pelvic endometriosis of sufficient severity to require in-hospital treatment.  Preventing that primary cesarean can play a critical role in reducing the number of women who will deal with the pain, complications and need for treatment of endometriosis that resulted from their cesarean surgery.  When considering cesarean surgery, women should be told of the excess risk of developing generalized pelvic endometriosis and cesarean-scar endometrioma and their consequent complications (pain, irregular bleeding, infertility) as part of the informed decision-making process.

_____________________

Did you know that an increase in endometriosis rates is a possible consequence of cesarean section? Are the women you are teaching and  working with aware of this potential development and what it might mean?  Do you consider this something that you would share in your role as Doula? Childbirth Educator? Midwife? OB?  Let us know in the comments. – SM

References

Andolf, E., Thorsell, M., & Kallen, K. (2013). Caesarean section and risk for endometriosis: a prospective cohort study of Swedish registries. BJOG. doi: 10.1111/1471-0528.12236

http://www.ncbi.nlm.nih.gov/pubmed/23663181

 

Cesarean Birth, Childbirth Education, Guest Posts, informed Consent, Maternity Care, Medical Interventions, New Research, Research, Uncategorized , , , , , , ,