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Can We Prevent Persistent Occiput Posterior Babies?

January 29th, 2013 by avatar

Today, regular contributor Henci Goer, co-author of the recent book, Optimal Care in Childbirth; The Case for a Physiologic Approach, discusses a just published study on resolving the OP baby during labor through maternal positioning.  Does it matter what position the mother is in?  Can we do anything to help get that baby to turn?  Henci lets us know what the research says in today’s post. – Sharon Muza, Community Manager

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In OP position, the back (occiput) of the fetal head is towards the woman’s back (posterior). Sometimes called “sunny side up,” there is nothing sunny about it. Because the deflexed head presents a wider diameter to the cervix and pelvic opening, progress in dilation and descent tends to be slow with an OP baby, and if OP persists, it greatly increases the likelihood of cesarean or vaginal instrumental delivery and therefore all the ills that follow in their wake.

Does maternal positioning in labor prevent persistent OP?

This month, a study titled “Is maternal posturing during labor efficient in preventing persistent occiput posterior position? A randomized control trial” reported on the use of maternal positioning in labor to rotate OP babies to occiput anterior (OA). Investigators randomly allocated 220 laboring women with OP babies either to assume positions designed to facilitate rotation or to recline on their backs. The positions were devised based on computer modeling of the mechanics of the woman’s pelvis and fetal head according to degree of fetal descent. The position prescribed for station -5 to -3, i.e., 3-5 cm above the ischial spines, a pelvic landmark, had the woman on her knees supporting her head and chest on a yoga ball. At station -2 to 0, i.e., 2 cm above to the level of the ischial spines, she lay on her side on the same side as the fetal spine with the underneath leg bent, and at station > 0, i.e., below the ischial spines, she lay on her side on the same side as the fetal spine with the upper leg bent at a 90 degree angle and supported in an elevated position.

http://flic.kr/p/9Rs7mL

 

The good news is that regardless of group assignment, and despite virtually all women having an epidural (94-96%), 76-78% of the babies eventually rotated to OA. The bad news is that regardless of group assignment, 22-24% of the babies didn’t. As one would predict, 94-97% of women whose babies rotated to OA had spontaneous vaginal births compared with 3-6% of women with persistent OP babies. Because positioning failed to help, investigators concluded: “We believe that no posture should be imposed on women with OP position during labor” (p. e8). 

Leaving aside the connotations of “imposed,” does this disappointing result mean that maternal positioning in labor to correct OP should be abandoned? Maybe not.

Of the 15 women with the fetal head high enough to begin with position 1, no woman used all 3 positions because 100% of them rotated to OA before fetal descent dictated use of position 3. I calculated what percentage of women who began with position 2 or 3, in other words fetal head at -2 station or lower, achieved an OA baby and found it to be 75%—the same percentage as when nothing was done. What could explain this? One explanation is that a position with belly suspended is more efficacious regardless of fetal station, another is that positioning is more likely to succeed before the head engages in the pelvis, and, of course, it may be a combination of both.

Common sense suggests that the baby is better able to maneuver before the head engages in the pelvis. If so, it seem likely that rupturing membranes would contribute to persistent OP by depriving the fetus of the cushion of forewaters and dropping the head into the pelvis prematurely. Research backs this up. A literature search revealed a study, “Associated factors and outcomes of persistent occiput posterior position: A retrospective cohort study from 1976 to 2001” finding that artificially ruptured membranes was an independent risk factor for persistent OP. Returning to the trial, all women had ruptured membranes because it was an inclusion factor. One wonders how much better maternal positioning might have worked had this not been the case, and an earlier trial offers a possible answer.

In the earlier trial, “Randomized control trial of hands-and-knees position for occipitoposterior position in labor,” half the women had intact membranes. Women in the intervention group assumed hands-and-knees for at least 30 minutes during an hour-long period while the control group could labor in any position other than one with a dependent belly. Twelve more women per 100 had an OA baby at delivery, a much bigger difference than the later trial. Before we get too excited, though, the difference did not achieve statistical significance, meaning results could have been due to chance. Still, this may have been because the population was too small (70 intervention-group women vs. 77 control-group women) to reliably detect a difference, but the trial has a bigger problem: fetal head position at delivery wasn’t recorded in 14% of the intervention group and 19% of the control group, which means we don’t know the real proportions of OA to OP between groups.

Take home: It looks like rupturing membranes may predispose to persistent OP and should be avoided for that reason. The jury is still out on whether a posture that suspends the belly is effective, but it is worth trying in any labor that is progressing slowly because it may help and doesn’t hurt.

Does maternal positioning in pregnancy prevent OP labors?

Some have proposed that by avoiding certain postures in late pregnancy, doing certain exercises, or both, women can shift the baby into an OA position and thereby avoid the difficulties of labor with an OP baby. A “randomized controlled trial of effect of hands and knees posturing on incidence of occiput posterior position at birth (2547 women) has tested that theory. Beginning in week 37, women in the intervention group were asked to assume hands-and-knees and do slow pelvic rocking for 10 minutes twice daily while women in the control group were asked to walk daily. Compliance was assessed through keeping a log. Identical percentages (8%) of the groups had an OP baby at delivery.

Why didn’t this work? The efficacy of positioning and exercise in pregnancy is predicated on the assumption that if the baby is OA at labor onset, it will stay that way. Unfortunately, that isn’t the case. A  study, “Changes in fetal position during labor and their association with epidural anesthesia,” examined the effect of epidural analgesia on persistent OP by performing sonograms on 1562 women at hospital admission, within an hour after epidural administration (or four hours after admission if no epidural had been administered), and after 8 cm dilation. A byproduct was the discovery that babies who were OA at admission rotated to OP as well as vice versa.

Take home: Prenatal positioning and exercises aimed at preventing OP in labor don’t work. Women should not be advised to do them because they may wrongly blame themselves for not practicing or not practicing enough should they end up with a difficult labor or an operative delivery due to persistent OP.

Do we have anything else?

Larry P Howell aafp.org/afp/2007/0601/p1671.html

We do have one ray of sunshine in the midst of this gloom. Three studies of manual rotation (near or after full dilation, the midwife or doctor uses fingers or a hand to turn the fetus to anterior) report high success rates and concomitant major reductions in cesarean rates, if not much effect on instrumental vaginal delivery rates. One study, “Manual rotation in occiput posterior or transverse positions: risk factors and consequences on the cesarean delivery rate,” comparing successful conversion to OA with failures reported an overall institutional success rate of 90% among 796 women. A “before and after” study, “Digital rotation from occipito-posterior to occipito-anterior decreases the need for cesarean section,” reported that before introducing the technique, among 30 women with an OP baby in second stage, 85% of the babies were still OP at delivery compared with 6% of 31 women treated with manual rotation. The cesarean rate was 23% in the “before” group versus 0% in the “after” group. The third study, “Manual rotation to reduce caesarean delivery in persistent occiput posterior or transverse position,” compared 731 women having manual rotation of an OP baby in second stage with 2527 women having expectant management. The success rate of manual rotation was 74% and the overall cesarean rate in treated women was 9% versus 42% in the expectantly managed group.

Manual rotation is confirmed as effective, but is it safe? This last study reported similar rates of acidemia and delivery injury in newborns. As for their mothers, investigators calculated that four manual rotations would prevent one cesarean. The study also found fewer anal sphincter injuries and cases of chorioamnionitis. The only disadvantage was that one more woman per hundred having manual rotation would have a cervical laceration.Take home: Birth attendants should be trained in performing manual rotation, and it should be routine practice in women reaching full dilation with an OP baby.

What has been your experience with the OP baby?  Is what you are teaching and telling mothers in line with the current research?  Will you change what you say now that you have this update?  Share your thoughts in the comment section. – SM

References and resources

Cheng, Y. W., 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 Medicine19(9), 563-568.

Desbriere R, Blanc J, Le Dû R, et al. Is maternal posturing during labor efficient in preventing persistent occiput posterior position? A randomized controlled trial. Am J Obstet Gynecol 2013;208:60.e1-8. PII: S0002-9378(12)02029-7 doi:10.1016/j.ajog.2012.10.882

Kariminia, A., Chamberlain, M. E., Keogh, J., & Shea, A. (2004). Randomised controlled trial of effect of hands and knees posturing on incidence of occiput posterior position at birth. bmj328(7438), 490.

Le Ray, C., Serres, P., Schmitz, T., Cabrol, D., & Goffinet, F. (2007). Manual rotation in occiput posterior or transverse positions: risk factors and consequences on the cesarean delivery rate. Obstetrics & Gynecology110(4), 873-879.

Lieberman, E., Davidson, K., Lee-Parritz, A., & Shearer, E. (2005). Changes in fetal position during labor and their association with epidural analgesia.Obstetrics & Gynecology105(5, Part 1), 974-982.

Reichman, O., Gdansky, E., Latinsky, B., Labi, S., & Samueloff, A. (2008). Digital rotation from occipito-posterior to occipito-anterior decreases the need for cesarean section. European Journal of Obstetrics & Gynecology and Reproductive Biology136(1), 25-28.

Shaffer, B. L., Cheng, Y. W., Vargas, J. E., & Caughey, A. B. (2011). Manual rotation to reduce caesarean delivery in persistent occiput posterior or transverse position. Journal of Maternal-Fetal and Neonatal Medicine24(1), 65-72.

Simkin, P. (2010). The fetal occiput posterior position: state of the science and a new perspective. Birth37(1), 61-71.

Stremler, R., Hodnett, E., Petryshen, P., Stevens, B., Weston, J., & Willan, A. R. (2005). Randomized Controlled Trial of Hands‐and‐Knees Positioning for Occipitoposterior Position in Labor. Birth32(4), 243-251.

Recommended resource: The fetal occiput posterior position: state of the science and a new perspective http://www.ncbi.nlm.nih.gov/pubmed?term=simkin%202010%20posterior by Penny Simkin.


 

Babies, Cesarean Birth, Epidural Analgesia, Guest Posts, Maternity Care, Medical Interventions, Research , , , , , , , ,

Maternity Care On the National Agenda – New Opportunities for Educators and Advocates

January 17th, 2013 by avatar

Today, Amy Romano, CNM, MSN, Associate Director of Programs for Childbirth Connection (and former Community Manager for this blog) follows up last Thursday’s post, Have You Made the Connection with Childbirth Connection? Three Reports You Don’t Want to Miss with her professional suggestions for educators and advocates to consider using the data and information contained in these reports and offering your students, clients and patients the consumer materials that accompany them.- Sharon Muza, Community Manager.

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As we begin 2013, it is clear from my vantage point at the Transforming Maternity Care Partnership that the transformation is underway. In Childbirth Connection’s nearly century-long history, we’ve never seen so much political will from leaders, so much passion from grassroots advocates, and so much collaboration among clinicians and other stakeholders. This new landscape presents many new opportunities for educators and advocates.

One area of maternity care that has garnered increasing attention is the overuse of cesarean section, especially in low-risk women. Last year, the multi-stakeholder Maternity Action Team at the National Priorities Partnership set goals for the U.S. health care system and identified promising strategies to reach these goals. One of the goals was to reduce the cesarean section rate in low-risk women to 15% or less. This work served as the impetus for Childbirth Connection to revisit and update our Cesarean Alert Initiative. We undertook a best evidence review to compare outcomes of cesarean delivery with those of vaginal birth. Based on the results, we also updated and redesigned our consumer booklet, What Every Pregnant Woman Needs to Know About Cesarean Section. These are powerful new tools to help educators and advocates push for safer care, support shared decision making, and inform and empower women.

Two of the biggest obstacles to change have been persistent liability concerns and the current payment system that rewards care that is fragmented and procedure-intensive. Efforts to make maternity care more evidence-based or woman-centered often run up against policies and attitudes rooted in fear of lawsuits or increasing malpractice premiums, or against the reality that clinicians can not get easily reimbursed for doing the right thing. But these barriers are shifting, 

Recently the literature has provided example after example of programs that reduced harm and saw rapid and dramatic drops in liability costs as a result. That’s right – one of the best ways to decrease liability costs is to provide safer care. Rigorous quality and safety programs are the most effective prevention strategy among the ten substantive solutions identified in Childbirth Connections new report, Maternity Care and Liability. The report pulls together the best available evidence and holds potential liability solutions up to a framework that addresses the diverse aims of a high-functioning liability system that serves childbearing women and newborns, maternity care clinicians, and payers.  

The evidence and analysis show that some of the most widely advocated reforms do not stand up to the framework, while quality improvement programs, shared decision making, and medication safety programs, among other interventions, all have potential to be win-win-win solutions for women and newborns, clinicians, and payers. If we are to find our way out of the intractable situation where liability concerns block progress, we must learn to effectively advocate for such win-win-win solutions.  Advocates and educators can better understand these solutions by accessing the 10 fact sheets and other related resources on our Maternity Care and Liability page.

Evidence also shows that improving the quality of care reduces costs to payers. As payment reforms roll out, there will be many more opportunities to realize these cost savings. To predict potential cost savings, however, it is necessary to know how much payers are currently paying for maternity care. Surprising, this information has been largely unavailable, and as a result we have had to settle for using facility charges as a proxy. This is a poor proxy because payers negotiate large discounts, and because charges data do not capture professional fees, lab and ultrasound costs, and other services. Childbirth Connection, along with our partners at Catalyst for Payment Reform and the Center for Healthcare Quality and Payment Reform, recently commissioned the most comprehensive available analysis of maternity care costs. The report, The Cost of Having a Baby in the United States shows wide variation across states, high costs for cesarean deliveries, and rapid growth in costs in the last decade. It also shows the sky-high costs uninsured women must pay – costs that can easily bankrupt a growing family. Even insured women face significant out-of-pocket costs that have increased nearly four-fold over six years. Fortunately, health care reform legislation has made out-of-pocket costs for maternity care more transparent by requiring a simple cost sample to each person choosing an individual or employer-sponsored health plan.

Educators and advocates have to be able to help women be savvy consumers of health care. That means being informed about their options and also being able to identify and work around barriers to high quality, safe, affordable care. Childbirth Connection produced this trio of reports to provide a well of data and analysis to help all stakeholders work toward a high-quality, high-value maternity care system.

How Childbirth Educators and Consumer Advocates Can Help

 What is the first thing that you are going to do to join this maternity care transformation? Can you share your ideas for using this information in your classroom or with clients or patients.  Can you bring others on board to help with this much needed transformation?- SM

Childbirth Education, Evidence Based Medicine, Guest Posts, Healthcare Reform, Maternal Quality Improvement, Maternity Care, Patient Advocacy, Research, Research for Advocacy, Transforming Maternity Care , , , , , , , , , ,

It Takes a Professional Village! A Study Looks At Collaborative Interdisciplinary Maternity Care Programs on Perinatal Outcomes

September 19th, 2012 by avatar

The  Canadian Medical Association Journal, published in their September 12, 2012 issue a very interesting study examining how a team approach to maternity care might improve maternal and neonat aloutcomes.  The study, Effect of a collaborative interdisciplinary maternity care program on perinatal outcomes  is reviewed here.

The Challenge

Photo Source: http://www.flickr.com/photos/jstownsley/28337593/

The number of physicians in Canada who provide obstetric care has declined in past years for reasons that include increasing physician retirement, closure of rural hospitals, liability concerns, dissatisfaction with the lifestyle and a difficulty in accessing maternity care in a variety of settings.  While registered midwife attended births may be on the rise, midwives in Canada attend less than 10% of all births nationwide.   At the same time as the number of doctors willing or able to attend births decline, cesarean rates are on the rise,  causing pressure on the maternity care system, including longer hospital stays both intrapartum and postpartum, which brings with it the associated costs and resources needed to accommodate this increase.

The diversity of the population having babies in many provinces is increasing, presenting additional challenges in meeting the non-French/English speaking population, who are more at risk for increased obstetrical interventions and are less likely to breastfeed.

The Study

In response to these challenges, the South Community Birth Program was established to provide care from a consortium of providers, including family practice physicians, community health nurses, doulas, midwives and others, who would work together to serve the multiethnic, low income communities that may be most at risk for interventions and surgery.

The retrospective cohort study examined outcomes between two matched groups of healthy women receiving maternity care in an ethically diverse region of South Vancouver, BC, Canada that has upwards of 45% immigrant families, 18% of them arriving in Canada in the past 5 years.  One group participated in the South Community Birth Program and the other received standard care in community based practices.

The South Community Birth Program offers maternity care in a team-based shared-care model, with the family practice doctors, midwives, nurses and doulas working together .  Women could be referred to the program by the health care provider or self refer.  After a few initial standard obstetrical appointments with a family practice doctor or midwife occur to determine medical history, physical examination, genetic history, necessary labs and other prenatal testing, the women and their partners are invited to join group prenatal care, based on the Centering Pregnancy Model.  Approximately 20% of the first time mothers choose to remain in the traditional obstetric care model.  10-12  families are grouped by their expected due date, and meet for 10 scheduled sessions, facilitated by either a family physician or midwife and a community nurse.  Each session has a carefully designed curriculum that covers nutrition, exercise, labor, birth and newborn care, among other topics.  Monthly meetings to discuss individual situations and access to comprehensive electronic medical records enhanced the collaboration between the team. Trained doulas, who speak 25 different languages, also meet with the family once prenatally and provide one on one continuous labor support during labor and birth. The admitting midwife or physician remains in the hospital during the patient’s labor and attends the birth.

After a hospital stay of 24-48 hours, the family receives a home visit from a family practice physician or midwife the day after discharge. Clinic breastfeeding and postpartum support is provided by a Master’s level clinical nurse specialist who is also a board certified lactation consultant.  At six weeks, the mother is discharged back to her physician, and a weekly drop in clinic is offered through 6 months postpartum.

The outcomes of the women in the South Community Birth Program were compared to women who received standard care from their midwives or family practice physicians.  Similar cohorts were established of women carrying a single baby of like ages, parity, and geographic region, and all the mothers were considered low risk and of normal body mass index.

The primary outcome measured was the proportion of women who underwent cesarean delivery.  The secondary outcomes measured were obstetrical interventions and maternal outcomes (method of fetal assessment during labor, use of analgesia during labor, augmentation or induction of labor, length of labor, perineal tramau, blood transfusion and length of stay) and neonatal outcomes (stillbirth, death before discharge, Apgar score less than 7, preterm delivery, small or large for gestational age, length of hospital stay, readmission, admission to neonatal intensive care unit for more than 24 hours and method of feeding at discharge).

Results

There was more incidence of diabetes and previous cesareans in the comparison group but the level of alcohol and substance use was the same in both groups.  Midwives delivered 41.9% of the babies in the birth program and 7.4% of babies in the comparison group.

When the rate of cesarean delivery was examined for both nullips and multips, the birth group women were at significantly reduced risk of cesarean delivery and were not at increased risk of assisted vaginal delivery with forceps or vacuum.

Interestingly, the birth program women who received care from an obstetrician were significantly more likely to have a cesarean than those receiving in the standard program who also received care from an obstetrician.  More women in the birth program with a prior cesarean delivery planned a vaginal birth in this pregnancy, though the proportion of successful vaginal births after cesareans dd not differ between the two groups.

The women in the community birth program experienced more intermittent auscultation vs electronic fetal monitoring and were more likely to use nitrous oxide and oxygen alone for pain relief and less likely to use epidural analgesia (Table 3).  Though indications for inductions did not differ, the birth program women were less likely to be induced.  More third degree perineal tears were observed in the birth program group but less episiotomies were performed.  Hospital stays were shorter for both mothers and newborns in the community program.

When you look at the newborns in the birth program, they were at marginally increased risk of being large for gestational age and were readmitted to the hospital in the first 28 days after birth at a higher rate, the majority of readmissions in the community and standard care group were due to jaundice. Exclusive breastfeeding in the birth program group was higher than in the standard group.

Discussion

The mothers and the babies in the community birth program were offered collaborative, multidisciplinary, community based care and this resulted in a lower cesarean rate, shorter hospital stays, experienced less interventions and they left the hospital more likely to be exclusively breastfeeding. Many of the outcomes observed in this study, especially for the families participating in the South Birth Community Program are in line with Lamaze International’s Healthy Birth Practices.  There are many questions that can be raised, and some of them are are discussed by the authors.

Was it the collaborative care from an interdisciplinary team result in better outcomes?  Was there a self-selection by the women themselves for the low intervention route that resulted in the observed differences?  Are the care providers themselves who are more likely to support normal birth self-selecting to work in the community birth program? Did the fact that the geographic area of the study had been underserved by maternity providers before the study play a role in the outcomes? Did the emotional and social support provided by the prenatal and postpartum group meetings facilitate a more informed or engaged group of families?

I also wonder how childbirth educators, added to such a model program, might also offer opportunity to reduce interventions and improve outcomes  Could childbirth educators in your community partner with other maternity care providers to work collaboratively to meet the perinatal needs of expectant families?  Would bringing health care providers interested in supporting physiologic birth in to share their knowledge in YOUR classrooms help to create an environment where families felt supported by an entire skilled team of people helping them to achieve better outcomes.

Would this model be financially and logistically replicable in other underserved communities and help to alleviate some of the concerns of a reduction in obstetrical providers and increased cesareans and interventions without improved maternal and newborn outcomes? And how can you, the childbirth educator, play a role?

References

Azad MB, Korzyrkyj AL. Perinatal programming of asthma: the role of the gut microbiota. Clin Dev Immunol 2012 Nov. 3 [Epub ahead of print].

Canadian Association of Midwives. Annual report 2011. Montréal (QC): The Association; 2011. Available: www .canadianmidwives.org /data/document /agm %202011 %20inal .pdf

Farine D, Gagnon R; Maternal Fetal Medicine Committee of the Society of Obstetricians and Gynaecologists of Canada. Are we facing a crisis in maternal fetal medicine in Canada? J Obstet Gynaecol Can 2008;30:598-9.

Getahun D, Oyelese Y, Hamisu M, et al. Previous cesarean delivery and risks of placenta previa and placental abruption.Obstet Gynecol 2006;107:771-8.

Giving birth in Canada: the costs. Ottawa (ON): Canadian Institute of Health Information; 2006.

Godwin M, Hodgetts G, Seguin R, et al. The Ontario Family Medicine Residents Cohort Study: factors affecting residents’ decisions to practise obstetrics. CMAJ 2002;166:179-84.

Hannah ME. Planned elective cesarean section: A reasonable choice for some women? CMAJ 2004;170:813-4.

Harris, S., Janssen, P., Saxell, L., Carty, E., MacRae, G., & Petersen, K. (2012). Effect of a collaborative interdisciplinary maternity care program on perinatal outcomes. Canadian Medical Association Journal, doi: DOI:10.1503 /cmaj.111753

Ontario Maternity Care Expert Panel. Maternity care in Ontario 2006: emerging crisis, emerging solutions: Ottawa (ON): Ontario Women’s Health Council, Ministry of Health and LongTerm Care; 2006.

Reid AJ, Carroll JC. Choosing to practise obstetrics. What factors influence family practice residents? Can Fam Physician 1991; 37:1859-67.

Thavagnanam S, Fleming J, Bromley A, et al. A meta-analysis of the association between cesarean section and childhood asthma. Clin Exp Allergy 2008;38:629-33.

 

 

Babies, Breastfeeding, Cesarean Birth, Childbirth Education, Evidence Based Medicine, Fetal Monitoring, Healthy Birth Practices, Healthy Care Practices, Maternity Care, Medical Interventions, Midwifery, New Research, Research, Uncategorized , , , , , , , , , , , , , , ,

Unintended Consequences: Cesarean Section, The Gut Microbiota, and Child Health

July 12th, 2012 by avatar

Today’s guest post is written by Dr. Mark Sloan, pediatrician and author of Birth Day: A Pediatrician Explores the Science, the History and the Wonder of Childbirth.  Dr. Sloan takes a look at impact of cesarean birth on normal gut bacteria.  – SM

When I first learned some years ago that cesarean section was associated with an increased risk of childhood asthma and eczema, I eagerly awaited the rest of the story. What could the link possibly be? Epidurals? Anesthetics? Antibiotics? Something strange and exotic was afoot, I was certain.

Imagine my surprise, then, when a growing body of evidence pointed to an unexpected source: the newborn gastrointestinal tract and the microorganisms that live there.

How might intestinal bacteria play such a major role in the health and well-being of newborns and children? The answer lies in an ancient, mutually beneficial relationship between humans and bacteria, one that modern birth technology has dramatically altered.

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Creative Commons photo by Eric Erbe, Colorization by Christopher Pooley. USDA

“Microbiota” is the term used to describe the community of microorganisms—bacteria, viruses, and fungi—that normally live in or on a given organ in the body. There’s a unique microbiota that inhabits the mouth, for example, another that lives on the skin, and still another that populates the intestine, or gut. Given an intestinal surface area of about 2,700 square feet—more or less the size of a tennis court—the microbiota inhabiting the gut is the largest and most diverse in the body.

How large and diverse? The gut microbiota contains roughly one quadrillion cells—at least ten times as many cells as does the human body itself. More than 1,000 bacterial species having been identified to date, with unknown numbers yet to be discovered.

How do all those bacteria get there? The fetal intestine, in the absence of congenital infection, is sterile in utero. The bacteria that come to colonize the bowel are acquired during birth and shortly afterwards, a process that is very much influenced by how a baby is born.

The gut microbiota and mode of delivery

In vaginally-born babies, the bacteria destined for the gut microbiota originate primarily in the maternal birth canal and rectum. Once these bacteria are swallowed by the newborn, they travel through the stomach and colonize the upper and lower intestine, a complicated process that evolves rapidly.

Infants born by cesarean section—particularly cesareans performed before labor begins—don’t encounter the bacteria of the birth canal and maternal rectum. (If a cesarean is performed during labor the infant may be exposed to these bacteria, but to a lesser degree than in vaginal birth.) Instead, bacteria from the skin and hospital environment quickly populate the bowel. As a result, the bacteria inhabiting the lower intestine following a cesarean birth can differ significantly from those found in the vaginally-born baby.

Whatever the mode of delivery, a core gut microbiota is well established within a few weeks of life and persists largely intact into adulthood. A less stable peripheral microbiota—one that is more sensitive to changes in diet and environmental factors, like antibiotics—is created as well. Between one and two years of age, when weaning from breast milk typically leads to a diet lower in fat and higher in carbohydrates, the gut microbiota takes on its final, mature profile.

Development of the newborn immune system 

The dramatic first steps in immune system development take place at the same time the core microbiota is being formed, and the gut bacteria play a key role in that process.

In the hours and days following birth, the newly-arrived gut bacteria stimulate the newborn to produce white blood cells and other immune system components, including antibodies directed at unwelcome, disease-causing microorganisms. The bacteria of the microbiota also “teach” the newborn’s immune system to tolerate their own presence—to differentiate bacterial friend from foe, in other words.

In a cesarean birth the fledgling immune system is confronted with unfamiliar, often hostile bacteria—including Clostridium difficile, a particularly troublesome hospital-acquired bug. In addition, the healthy probiotic bacteria associated with vaginal birth (e.g., lactobacillus) arrive later and in lower numbers. These changes in the composition of the normal gut microbiota occur during a critical time in immune system development.

The cesarean-asthma theory (in a nutshell) 

Here’s how cesareans and asthma are likely connected:

Creative Commons photo by hemangi28

Humans evolved right along with the gut microbiota normally acquired during vaginal birth. When the composition of the microbiota is imbalanced, or unusual germs like Clostridium difficile appear, the immune system doesn’t like it. A low-grade, long-lasting inflammatory response directed at these intruders begins at birth, leading to a kind of weakness and “leakiness” of the intestinal lining. Proteins and carbohydrates that normally would not be absorbed from the intestinal contents—including large, incompletely digested food molecules—make their way into the infant’s bloodstream.

To make a very long story short, inflammation and the abnormal processing of food that results appear to increase the risk of asthma and eczema—and diabetes, obesity, and other chronic conditions—later in life.

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Normalizing the post-cesarean gut microbiota

 Reducing the cesarean rate is an obvious best practice in promoting a healthy gut microbiota. But there will always be a need for cesarean section, and so researchers are starting to focus on “normalization” of the gut microbiota of cesarean-born babies. Although there are as yet no proven therapies, here are some possibilities:

  • Probiotics. Though administering healthful probiotic bacteria to correct an imbalanced microbiota makes intuitive sense, studies to date have been disappointing, with only minor, short-lived changes changes to the gut microbiota. However, research into “good” bacteria and how they become established in the intestine is active and ongoing.
  • Direct transfer of maternal secretions. Placing maternal vaginal and rectal material into the newborn’s mouth has been proposed—more or less mimicking natural colonization—but to date there are no published studies to support the practice.
  • Fecal transplantation. Direct transfer of fecal material from healthy adults into the gastrointestinal tracts of people suffering from Clostridium difficile infections has shown promise. Could healthy parents serve as “donors” for their babies? Applying such technology to otherwise healthy newborns is highly impractical at present, to say the least. Still, refinements may someday make this a viable option.

Conclusion

A cesarean section doesn’t automatically condemn a child to a lifetime of asthma or eczema, just as a vaginal birth isn’t a guarantee of perfect health. But cesarean birth, by altering normal gut microbiota and immune system development, does appear to moderately increase the risk of these and other chronic health conditions. A woman who has the option of choosing her mode of delivery should add this to the many other factors she must weigh in deciding how her baby will be born.

Childbirth educators and other birth professionals, when you speak to your classes or clients about the benefits and risks of cesarean section, do you mention this information.  What do you think about this connection?  What should your students know about how to minimize the impact of cesarean on the future potential health of their children?  Please share your thoughts on the comment section,- SM

 Selected references:

1)    Effects of mode of delivery on gut microbiota composition 

Biasucci G, Rubini M, Riboni S, et al (2010). Mode of delivery affects the bacterial community in the newborn gut. Early Human Development 86:S13-S15

Penders J, Tjhijs C, Vink C, et al (2006). Factors influencing the composition of the intestinal microbiota in early infancy. Pediatrics 118(2):511-521.

Salimen S, Gibson GR, McCartney AL (2004). Influence of mode of delivery on gut microbiota in seven year old children. Gut 53:1388-1389.

2)    Development of the newborn immune system

Huurre A, et al (2008). Mode of delivery: Effects on gut microbiota and humoral immunity. Neonatology 93:236-240.

Johnson C, Versalovic J (2012). The human microbiome and its potential importance to pediatrics.  Pediatrics (published online April 2, 2012; DOI: 10.1542/peds2011-2736).

Vael C, Desager, K (2009). The importance of the development of the intestinal microbiota in infancy. Current Opinion in Pediatrics 21(6):794-800

3)    Cesarean birth, gut microbiota, and asthma/atopic disease

Azad M, Korzyrkyj A (2012). Perinatal programming of asthma: The role of the gut microbiota. Clinical and Developmental Immunology Volume 2012; Article ID 932072; doi:10.1155/2012/932072

Thanvagnanam S, Fleming J, Bromley A, et al (2008). A meta-analysis of the association between caesarean section and childhood asthma. Clinical & Experimental Allergy 38(4): 629-633.

van Nimwegen F, Penders J, Stobberingh E, et al (2011). Mode and place of delivery, gastrointestinal microbiota, and their influence on asthma and atopy. Journal of Allergy and Clinical Immunology 128(5):948-955.e3

About Mark Sloan, M.D.

Mark Sloan has been a pediatrician and a Fellow of the American Academy of Pediatrics for more than 25 years. Since 1982, he has practiced with the Permanente Medical Group in Sacramento and Santa Rosa, California, where he was Chief of Pediatrics from 1997 to 2002. He is an Assistant Clinical Professor in the Department of Community and Family Medicine at the University of California, San Francisco. Dr. Sloan’s first book, Birth Day: A Pediatrician Explores the Science, the History and the Wonder of Childbirth was published in 2009 by Ballantine BooksHis writing has appeared in the Chicago Tribune, the San Francisco Chronicle, the San Francisco Examiner, and Notre Dame Magazine, among other publications.  Dr. Sloan can be reached through his blog.

 

 

Babies, Cesarean Birth, Childbirth Education, Evidence Based Medicine, Guest Posts, Healthy Care Practices, informed Consent, Newborns, Practice Guidelines, Push for Your Baby, Research, Uncategorized , , , , , , , ,

Delivery By Cesarean Section And Risk Of Obesity In Preschool Age Children; Research Review

June 21st, 2012 by avatar

Today’s guest post is written by Dr. Mark Sloan, pediatrician and author of Birth Day: A Pediatrician Explores the Science, the History and the Wonder of Childbirth.  Dr. Sloan takes a look at the study released in May, 2012 examing the relationship between Cesarean deliveries and obesity in preschoolers. – SM

I don’t recall learning much about childhood obesity in my early-1980s pediatric residency. This was partly due to the fact that obesity wasn’t all that common—only about 7% of kids fell into that category at the time—and partly because the solution seemed obvious, and not quite worthy of medical attention. “Join a baseball team, kid,” my senior resident once told an overweight boy with asthma. “And you,” he said, pointing an accusatory finger at the boy’s mother. “Stop buying cookies, okay?”

Creative Commons photo by LouLou-Nico

One thing I did learn a lot about in residency, though, was cesarean section. The U.S. cesarean rate topped 20% for the first time, up from 6% just a decade earlier.  I spent a steadily increasing amount of time in operating rooms, waiting for an obstetrician to hand me a baby.

We all thought the rise in cesareans was a good thing—think of the lives saved, the brain damage avoided, we told ourselves.  If anyone had suggested cesarean birth might be creating long-term health problems for those “saved” babies, we would have scoffed. And had anyone suggested that it might lead to a lifetime of obesity, we’d have laughed them right out of the hospital.

But here we have it: The cesarean rate is now 50% higher than it was in 1980. (Hamilton BE, Martin JA, & Ventura SJ. 2011)  The rate of childhood obesity has tripled. (Ogden C. & Carroll M., 2010) Is this just a coincidence?

Theories abound as to the cause of the childhood obesity epidemic. It’s all those sodas and sports drinks laden with high fructose corn syrup. Or it’s sugary, fatty, super-sized fast food. Or video games, the loss of Physical Education at school, bad parenting, unsafe neighborhoods, too little sleep, too much schoolwork, or all of the above. Just about any variable you can think of has been scrutinized for obesogenic potential.

And now, thanks to Dr. Susanna Huh and her research team at Harvard University, we can add cesarean section to the list of suspects.

Creative Commons photo

Huh’s team studied 1,255 mother-child pairs recruited between 1999 and 2002 as part of Project Viva, a longitudinal prebirth cohort of mothers and babies in eastern Massachusetts. A trained research assistant conducted in-person visits with the mothers during pregnancy, and with mothers and babies shortly after delivery, and at 6 months and 3 years after birth. At each visit the children’s length, weight and skin-fold thicknesses were assessed.

Their results: Children born by cesarean section were twice as likely to be obese at 3 years of age than those born vaginally. (Huh, SY, Rifas-Shiman, SI, Zera, CA, Edwards, JWR, Oken, E, Weiss, ST, & Gillman, MW, 2012) This relationship held up even after adjusting for factors like the mother’s weight, ethnicity, age, education, and parity, and the baby’s gender, gestational age, and birth weight.

The Huh study wasn’t designed to look at the reasons for the increased risk of obesity associated with cesarean birth, but the Harvard team suggested several possibilities:

  1. The most likely culprit is the known alteration of the gut microbiota—the sum total of all the micro-organisms found in the healthy human bowel—caused by cesarean birth. The microbiota of vaginally-born babies is populated by bacteria acquired from the birth canal and maternal rectum. In cesarean-born babies, who do not traverse the birth canal, the microbiota is dominated by bacteria from the skin and the hospital environment. In general, cesarean-born babies have an abnormal gut microbiota: too many carbohydrate-loving Firmicutes bacteria and too few obesity-preventing Bacteroidetes species, compared with the microbiota found in vaginally-born babies. This same gut microbiota profile is associated with obesity in adults; the link between the two appears to be low-level bowel inflammation triggered by the abnormal microbiota, which alters how food is absorbed  from the gut and processed within the body.
  2. The second possibility is that cesarean birth is just a stand-in for something else that’s happening at the same time. In discussing their findings, Huh and colleagues speculate about antibiotics routinely given to women during the course of a cesarean. Antibiotics given during pregnancy may temporarily alter the newborn gut microbiota, but research results are mixed as to whether this is a significant, lasting effect.
  3.  It’s possible that all of this has nothing to do with the gut microbiota. There are maternal and placental hormones, and immune and inflammatory factors, surging in a mother’s (and baby’s) bloodstream during labor. These, obviously, are missing to some extent if she never completes labor, and are largely absent if a cesarean is performed before labor starts. The lack of a normal maternal stress response to labor could adversely impact the development of the newborn immune system, theoretically leading to the gut inflammation associated with obesity.
  4.  Differences in mode of feeding may be involved as well. The study’s cesarean babies breast-fed for a significantly shorter time than did the vaginally-born babies. Though the authors don’t comment on this, early weaning is also associated with alterations of the infant gut microbiota.

My best guess: the cesarean-obesity link is likely a big mash-up of all of these, plus other factors no one has yet even dreamed of. Further research by Dr. Huh’s team and many others in the coming months and years will hopefully clarify the picture.

In the meantime, the risk of future obesity is one more factor maternity care providers and their pregnant clients should weigh before deciding on how a baby will be born.

Would you be likely to share this connection between mode of delivery and childhood obesity with  your students when teaching about benefits and risks of cesarean section?  Do you think if more families knew about this connection, they might make different choices surrounding the labor and birth of their baby and avoid interventions likely to increase their risk of a cesarean birth.  Is this information just one more thing that blames mothers for things that are out of their control?  Please share your thoughts in our comment section. -SM

References

Hamilton BE, Martin JA, Ventura SJ. Births: Preliminary data for 2010. National vital statistics reports; vol 60 no 2. Hyattsville, MD: National Center for Health Statistics. 2011.

 Huh, Susanna Y, Rifas-Shiman, Sheryl L, Zera, Chloe A, Edwards, Janet W Rich, Oken, Emily, Weiss, Scott T, & Gillman, Matthew W. (2012). Delivery by caesarean section and risk of obesity in preschool age children: a prospective cohort study. Archives of Disease in Childhood. doi: 10.1136/archdischild-2011-301141

Ogden Cynthia, & Carroll Margaret, U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, Division of Health and Nutrition Examination Surveys (2010). Prevalence of obesity among children and adolescents: United states, trends 1963-1965 through 2007-2008. Retrieved from CDC/National Center for Health Statistics website: http://www.cdc.gov/nchs/data/hestat/obesity_child_07_08/obesity_child_07_08.htm

About Mark Sloan

Mark Sloan has been a pediatrician and a Fellow of the American Academy of Pediatrics for more than 25 years. Dr. Sloan graduated from the University of Notre Dame in 1975, received his medical degree from the University of Illinois, Chicago, in 1979, and completed his pediatric training at the University of Michigan. Since 1982 he has practiced with the Permanente Medical Group in Sacramento and Santa Rosa, California, where he was Chief of Pediatrics from 1997 to 2002. He is an Assistant Clinical Professor in the Department of Community and Family Medicine at the University of California, San Francisco. Dr. Sloan’s first book, Birth Day: A Pediatrician Explores the Science, the History and the Wonder of Childbirth was published in 2009 by Ballantine Books. His writing has appeared in the Chicago Tribune, the San Francisco Chronicle, the San Francisco Examiner, and Notre Dame Magazine, among other publications. Dr. Sloan can be reached through his blog.

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