Cesareans and chronic childhood disease: Time for a public discussion

From the Ishinhō, Japanese medical text, 1860

From the Ishinhō, Japanese medical text, 1860

In an analysis published in the most recent edition of The BMJ, Drs. Jan Blustein and Jianming Liu examine the evidence that cesarean delivery is associated with an increased risk of chronic childhood diseases like asthma, type 1 diabetes, and obesity. Their conclusion: the bulk of the evidence suggests that the association is real.

The time has come, Blustein and Liu write, for maternity care providers to include the risk of chronic childhood disease in their discussions with women considering a “non-essential” cesarean, such as when the choice is between a VBAC or repeat cesarean, or in the case of a woman choosing a medically unneccessary cesarean in lieu of vaginal birth—the so-called “maternal request” cesarean.

This topic has intrigued me for some time now. As part of my recently completed MPH program at the University of Minnesota, I wrote a paper titled, “Do Cesarean Sections Increase the Risk of Child Asthma? A Systematic Literature Review.”

In writing the paper I read and analyzed every research study on the subject since 2001. Roughly two-thirds of those studies detected a small-to-moderate association between cesarean birth and childhood asthma. (In fact, 90% of the studies detected an association between the two, but not all were statistically significant.) Most of the studies that didn’t find the association were seriously flawed—too few subjects, for example, or ignoring possible confounders, like prematurity or a history of maternal asthma. Three meta-analyses (two in 2008, one in 2014) all reached similar conclusions: cesarean section is associated with about a 20% increase in the risk of child asthma.

My paper was limited to asthma, but as described in the BMJ analysis there’s evidence that cesareans increase the risk of other chronic childhood illnesses, too–type 1 diabetes and obesity. A 2015 study by Sevelsted et. al. analyzed a cohort of two million Danish children and found small-to-moderately increased risks of juvenile rheumatoid arthitis, connective tissue disorders, inflammatory bowel diseases, immune deficiencies, and even leukemia.

Given that body of evidence, you’d think that organizations like ACOG (the American Congress of Obstetricians and Gynecologists) and the U.K.’s National Institute for Health and Care Excellence would be pushing their members to share this information with their pregnant patients. But they’re not. According to Blustein and Liu,

“…knowledge about chronic disease risks could affect decision making in non-essential caesarean. The American College of Obstetrics and Gynecology and the UK’s National Institute for Health and Care Excellence recently issued consensus statements on caesarean delivery at maternal request. Based on evidence about maternal and perinatal outcomes, both groups concluded that a pregnant woman requesting caesarean should have that choice, if she still desires it after discussion of the risks and benefits of the procedure. Importantly, neither group acknowledged the long term risk of chronic disease. [Emphasis mine.]

Critics can (and do) point to the uneven quality and designs of the studies that support such links—it’s association versus causation all over again—but that’s not entirely fair. To prove beyond doubt that cesarean birth increases the risk of child asthma, you’d have to do trials where women are randomly assigned to cesarean or vaginal birth…which, as you can imagine, is a practical and ethical non-starter. That leaves us with observational studies, which can only point out that two things seem to be related, not that they definitely are.

Ah, but there has been a randomized study of the long-term effects of cesareans versus vaginal birth in term, breech deliveries, and at least one research team has made the case that randomized trials of mode of delivery aren’t really unethical. More on those topics soon.

Finally, just to re-re-reiterate: I’m not anti-cesarean. My wife and son are alive and well today thanks to a medically necessary cesarean. But the cesarean rate today is 6 times higher than it was when I was a junior in high school (1970, if you must know…). As Blustein and Liu point out in their analysis:

“We live in a world where caesarean rates cannot be explained by compelling medical indications.”

Perhaps increased awareness of the potentially negative impact of cesareans on child health will help reverse that decades-long trend.

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Filed under Asthma, Cesareans, Diabetes, Obesity, VBAC

Readers respond: Cord clamping around the U.S.

Unknown“Who even does early cord clamping anymore?”

This question was raised recently by a young doctor at the family medicine residency program where I teach. She and her residency colleagues had been taught in their OB rotation that delayed cord clamping is the childbirth standard of care. The benefits are proven, the resident said, and early clamping doesn’t do anything for anybody.

“So why would anyone do it?”

Good question. Yet judging from the emails I received after my last post, DCC is far from the standard of care around the country:

  • An East Coast doula wrote that her clients can have DCC performed at birth “if they request it.” (If they request it?? That’s a bit like saying, “There’s this thing called oxygen, and if it looks like your baby’s at risk of brain damage from a lack of it, we can give him some. If you ask us to, that is.”)

  • A California midwife wrote that the obstetricians at her hospital are adamant that DCC is “too risky” for newborns. Despite the evidence she presented to them, they’re sticking with ECC.

  • A Midwestern family physician reported that the DCC/ECC debate has split the medical staff where she practices. Although there’s some overlap, the family docs are largely pro-DCC, while the OB staff is in favor of ECC.

Clinging to interventions that have been shown to be useless and even harmful is, unfortunately, nothing new in the history of medicine.

Poor Ignaz...

Poor Ignaz…

Perhaps the most infamous example in the maternity care world is that of Dr. Ignaz Semmelweis (1818-1865), a Hungarian-Austrian obstetrician who clearly demonstrated that simple handwashing could greatly reduce maternal deaths from puerperal fever—a virulent infection that plagued crowded maternity wards in the 19th century. Everybody ignored him, his career crashed, and he died in an asylum…and a few decades later everyone was washing their hands. (A brief synopsis of his story is attached below, excerpted from my book, Birth Day: A Pediatrician Explores the Science, the History, and the Wonder of Childbirth.)*

I’m encouraged that the young doctors I work with see DCC as a no-brainer (or a pro-brainer, if you’ll pardon the pun.) But too many doctors don’t see the timing of cord clamping as the important issue it is. For them, it will probably take the Invisible Hand of the Market, in the form of pressure from pregnant clients, to change minds and practices, if not hearts.Adam Smith, Invisible Hand-8x6

So tell me, what’s the DCC/ECC environment where you live? Email me or (better still) add a comment on the blog!

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*(Shameless self-promotion: Birth Day—a ripping good yarn—is available in paperback or Kindle from Amazon, or you can order it from me directly at www.marksloanmd.com).

Excerpt from Birth Day: A Pediatrician Explores the Science, the History, and the Wonder of Childbirth (Copyright 2009, Mark Sloan M.D.)

“In 1844, Dr. Ignaz Semmelweis, an assistant lecturer in the First Obstetric Division of the Vienna Lying-in Hospital, began to make the same connection [as Dr. Oliver Wendell Holmes]. Semmelweis noticed that women who gave birth in his First Division, which was staffed by doctors and medical students, had eight times the risk of contracting puerperal fever than those who were delivered by midwives in a distant part of the hospital. Of the many differences in patient care between the two divisions, Semmelweis saw one that stood out. Doctors did autopsies on women who had died of puerperal fever. Midwives did not.

With no access to Holmes’s still obscure paper, it took three years and a number of failed hypotheses for Semmelweis to put it all together. The final piece of the puzzle fell into place when, like Holmes, he was struck by the similarities between puerperal fever and the death of a colleague from an infection incurred during an autopsy. “Suddenly a thought crossed my mind,” he wrote. “The fingers and hands of students and doctors, soiled by recent dissections, carry those death-dealing cadavers’ poisons into the genital organs of women in childbirth.”

Semmelweis immediately ordered all doctors and students in the First Division to wash their hands in a chlorinated lime solution before attending to patients. The results were startling: mortality rates from puerperal fever fell from 18 percent in the first half of 1847 to less than 3 percent by that November. But like Holmes’s in America, Semmelweis’s breakthrough was dismissed by his colleagues, including Friedrich Scanzoni, the most prominent obstetrician in Vienna.

Semmelweis’s discovery ultimately led to the ruin of his own career and health. He was dismissed from the Vienna Lying-in Hospital in 1849, in large part because of his increasingly strident arguments with colleagues. Despondent, he spent a few unproductive years at a hospital in his native Hungary before returning to Vienna. There he wrote articles and letters blasting his former colleagues. He even accused them of murder, calling them, among other things, “medical Neros” for ignoring his advice while women died. Disabled by severe depression, Semmelweis died in a mental hospital in 1865—ironically, from an infection that started in a cut on his finger.”

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Filed under Cord clamping, Doulas, History of Medicine, Iron deficiency

The benefits of delayed cord clamping: New evidence

Hold on a minute (or three)!

Hold on a minute (or three)!

Something about the cord clamping debate has troubled me for quite some time now. Long after early cord clamping (ECC) was shown to be of no benefit to either mother or baby, and in fact may harm the baby through loss of iron during a critical period of brain development, some in the obstetrics community wanted to see more evidence before endorsing delayed cord clamping (DCC) for healthy term babies. The pro-DCC evidence was theoretical, they claimed; before they agreed to wait a couple of extra minutes to clamp the cord, they wanted hard proof that DCC actually helps babies.

The logic behind this foot-dragging—“We’re not abandoning a pointless practice without a darned good reason,” more or lessescapes me. After all, this isn’t like switching from one way of transplanting hearts to another. DCC doesn’t require new equipment or extensive training, and it’s not a budget-buster, either. You simply wait 2 or 3 minutes to clamp the cord, instead of doing it right at birth. It’s not brain surgery.

Well, there’s finally some solid evidence for the hard-to-convince, pro-ECC crowd. In a recently published randomized clinical trial, a Swedish research team led by Dr. Ola Andersson discovered that a group of healthy children who had been randomized to receive DCC (3 minutes after birth) had significantly better personal-social and fine-motor functioning at 4 years of age than did those who were randomized to receive ECC (< 10 seconds after birth). The effect was more marked in boys than in girls.

Andersson and colleagues checked the children’s iron stores at several points and found that, while DCC babies had more total body iron at 4 months of age, the ECC/DCC difference disappeared by 12 months of age. Looking at neurodevelopment, they found no differences between ECC and DCC babies at 12 months, but by 4 years the DCC children showed significant developmental advantages over the ECC group. It seems like an odd finding: how could a DCC-related “bump” in iron stores in early infancy cause developmental differences at 4 years but not at 12 months?

It likely comes down to an inadequate supply of iron at a critical time in neurodevelopment—those first few months, when many of the brain’s critical neural pathways are established. The resulting delays weren’t detectable with the kind of screening that can be done on a 12-month old, but by 4 years of age more extensive testing could pick it up.

The most important thing about this study is that it was a randomized clinical trial, a study design that can show that “a” is directly connected to “b”. The researchers in this case took two evenly matched groups of infants, randomly assigned them to different treatments (DCC or ECC), and then measured the relevant outcomes (iron stores + developmental differences). While there are some shortcomings to the study—the number of kids involved isn’t huge, for example—the findings fit with what’s currently known about the effects of iron deficiency in early childhood.

This study presents a solid argument in favor of DCC. And if that’s not enough to sway ECC advocates, what is?

More on iron metabolism (and why boys are affected more than girls) in upcoming posts…

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Filed under Cord clamping, Development, Iron deficiency

School’s out! Now, where was I??

Graduation day!

Graduation day!

Astute readers of this blog may have noted that I apparently fell off the planet a few months back. Not so! The explanation for my writerly absence is pretty straightforward–I was working on my Masters in Public Health from the University of Minnesota (Go Gophers!) and using up all my writing energy on reports, papers, and online class posts. Given the fact that I last attended college in 1975, it was a bit of a slog at first.

But, huzzah! I finish up tomorrow, and will now re-grace the World Wide Web with my opinions on a range of maternal-child health issues (and anything else I feel like writing about). There’s new research on cesareans, cord clamping and breastfeeding, among other topics, and I’ve gotten interested in the role of ACEs (Adverse Childhood Experiences) and toxic stress on child neurodevelopment. So many things!

So let me take this opportunity to welcome myself back, and to vow that–although I am eternally grateful to the U of M for an enjoyable learning experience–I am also eternally done with getting degrees.

I look forward to hearing from you as the blog posts re-accumulate. Onward!

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Epidurals: Do they prevent postpartum depression?

Leonardo da Vinci

Leonardo da Vinci

Do epidurals prevent postpartum depression? That’s the intriguing conclusion some people are drawing from a study published in this month’s issue of Anesthesia and Analgesia. But is that conclusion correct?

In a study of 214 women at Peking First University Hospital in Beijing, researchers found that 14% of women who received epidural analgesia during labor reported symptoms of postpartum depression (PPD) six weeks later, compared with 34.6% of women who refused epidurals. The authors point out that their findings don’t necessarily prove that epidurals can prevent PPD, but the language in the discussion sure sounds like that’s what they believe.

But…the premise of this study is flawed from the start, because the investigators compared epidural analgesia to, well, nothing:

“Each parturient made a decision by herself to have epidural labor analgesia or no pain relief at all. Other forms of analgesia are not available at our hospital.”

What does “no pain relief at all” mean at Peking First University Hospital?  Were spouses/doulas/other support people allowed in the room? Did the mothers labor alone? Does “no pain relief at all” mean no freedom to move about, no bath/massage/music/visualization exercises/birth balls, none of the myriad other comfort measures that can reduce pain during labor? It obviously means no nitrous oxide, and I presume no tylenol or ibuprofen, either. In this particular hospital it seems, the choice is pretty stark: you get an epidural or you tough it out.

Which means we’re left with a study of unaddressed labor pain and postpartum depression, not the benefits of epidurals.

Karl Gauss, inventor of Twilight Sleep

Not exactly “new news”: Dr. Karl Gauss, inventor of Twilight Sleep

It’s hardly news that uncontrolled pain can lead to postpartum depression. One of the main drivers in the “painless childbirth” movement of the mid-19th century and the development of Twilight Sleep in the early 20th century was the prevention of neurasthenia—a debilitating combination of anxiety and depression that haunted many postpartum women.* 

This study would be more compelling if the authors had compared epidurals with other pain relief modalities in the setting of a well-supported labor. Otherwise we’re left with the conclusion that uncontrolled labor pain can make women miserable, and medically obliterated pain makes them less so. 

I can’t think of any other form of human pain that would be studied in such an all-or-none way.

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* Department of Shameless Self-Promotion: You can read more about the history of painless childbirth, as well as what a lousy labor coach I was, in my book, Birth Day: A Pediatrician Explores the Science, the History, and the Wonders of Childbirth.  

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Filed under Birth Day, Labor pain, Maternal-child health, Natural childbirth

Is it the cesarean, or the absence of labor?

Stem cells, pondering the future

Stem cells, pondering the future

I’ve written a fair amount about the association between cesarean birth and the increased risk of immune-related diseases like asthma, diabetes, celiac disease, and even obesity. Most of the research out there has focused on the newborn gut microbiota—the collection of bacteria that colonize a baby’s intestines at birth and play a key role in the development of the immune system. These bacteria are primarily acquired from the mother’s birth canal and rectum during a vaginal birth, but for cesarean-born babies those “pioneer” bacteria are often derived from the hospital environment. Such “wrong” bacteria in the bowel early on can lead to inflammation and, the theories go, to immune-related diseases later in life.

But is the cesarean per se at the root of all this? Or might the absence of labor (or an incomplete labor) have something to do with it? Childbirth is, after all, a fabulously complicated dance of maternal and fetal hormones, anti-oxidants, and other chemicals that are known to influence the immune system. What happens to the newborn’s immune system development when that dance is cut short, or never starts in the first place?

A study from Sweden’s Karolinska Institutet published in the current issue of the American Journal of Obstetrics and Gynecology has me wondering about the “absent-labor” scenario again. The study’s authors compared cord blood samples from babies born by elective cesarean section (ECS) with those who were vaginally born (VB). They looked specifically at hematopoietic stem cells—the precursor cells that go on to become, among other things, the white blood cells that play a critical role in the human immune system.

Here’s what they found: the DNA in stem cells from ECS babies was significantly different from that of the VB babies, particularly in an area devoted to production of antibodies. The study’s genetic analysis is way above my pay grade, but boiled down to the essentials, the differences are all about epigenetics, which is defined as:

 “…the study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in DNA sequence.”

Ouch!

Plain English version (mine): Epigenetics is the study of how genes are turned on and off, typically by the addition of methyl groups (ouch, again!) to genes. The timing of all this light-switch-like activity, and the potential for permanent change, has big-time implications for health throughout life.

The Swedish researchers found that stem cell DNA methylation (the addition of methyl groups to genes) increased steadily with the duration of labor. So one could conclude, couldn’t one, that normal labor plays an important role in preparing future white blood cells for their task, and, ergo, the absence of labor is why everyone’s so chubby these days? Sure, one could conclude that…but one would be jumping the gun, big time.

Hold that smokin' gun, pardner!

Hold that smokin’ gun, pardner!

Why? Because this was a small, observational study—the kind of study designed to make readers sit up and take notice (Hmm…that’s interesting!”) but that requires much more research before any guns start smoking. The small numbers of subjects in this study makes it easier for error to creep in, for example, and there were significant differences between the mothers as well—the ECS group was significantly older than the VB group, and their babies were born an average of a week and a half earlier, factors which might cause their own epigenetic effects.

It’s going to take much larger studies to see if these findings are in fact true, and if so to tease out how significant such cesarean-related epigenetic changes may be in the grand scheme of childhood immune system diseases. A lot of vaginally born kids end up asthma, after all. Including me.

But still, how fascinating! I’m looking forward to reading more about this.

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Photos courtesy Joseph Elsbernd, Jim Sher

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Filed under Asthma, Cesareans, Gut microbiota, Natural childbirth, Obesity

Shout-out #1: Enlightened Mama in the Twin Cities

Such a place!

Such a place!

I’ve given a couple of talks in the Midwest this month, and I want to give a shout-out to two very worthy organizations: Enlightened Mama in St. Paul, Minnesota (this post) and Southwest Tech in Fennimore, Wisconsin (coming soon).

I first met Liz Abbene, Enlightened Mama’s founder and “Alpha Mama,” a couple of years ago when I was speaking at the 2012 REACHE conference in Seattle. As we chatted about the conference I was impressed by Liz’s ability to carry on a coherent conversation while buried in children (she has four beautiful kids). Anyone who could keep that many balls in the air at one time, I figured, must run a pretty interesting business.

When the conference wound down, Liz extended me an invitation to speak at Enlightened Mama if I was ever in the Twin Cities. Sure, I said, figuring what are the chances of that ever happening? I’d never been to the Twin Cities and didn’t really have any plans to travel there.

Liz Abbene

Liz Abbene

Ah, but life has a way of changing one’s plans. Last year I enrolled in the University of Minnesota’s Masters in Public Health program, which requires online students to spend a couple of weeks on campus during the year. So I came to the Twin Cities for UMN’s Public Health Institute in early June and, as Liz had willed back in Seattle, I wound up at Enlightened Mama talking on the wonders of the newborn microbiome.

Space does not allow me to describe all that Liz does at Enlightened Mama. Suffice it to say that along with doula services she and her staff and partners provide lactation support and breastfeeding classes; massage, acupuncture and chiropractic care; family therapy and career counseling; and a number of other classes and services that promote wellness before, during, and after childbirth. Alas, there is no brewpub or nail salon at Enlightened Mama, but for all I know these are in the works.

Enlightened Mama is a great resource for families in the Minneapolis-St.Paul area. So if you live there and you’re pregnant, give Liz a call!

P.S: When I asked one St. Paul mother how her town differed from Minneapolis, she told me this:

“People from Minneapolis love to tell you how cool it is to live there. People from St. Paul already know we live in a cool town. No need to brag about it.”

I remain neutral in the matter…

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Filed under Breastfeeding, Doulas, Maternal-child health, Natural childbirth