Science Based Medicine last covered the increasingly common practice of laboring while immersed in water, in many cases followed by delivering the baby while still submerged, a little over four years ago. In that post, Dr. Amy Tuteur focused primarily on the contamination of the water with a variety of potentially pathogenic bacteria and the associated risk of infection. She also touched on the some of the other risks of giving birth underwater and made some excellent arguments against many of the claims made by proponents. I recommend reading that post and the ensuing comments.

This week, a new joint clinical report from the American Academy of Pediatrics (AAP) and the American College of Obstetricians and Gynecologists (ACOG) on immersion in water during labor and delivery was published in both the April Pediatrics and on the ACOG website. The media has responded with the typical flurry of falsely dichotomous coverage, pitting maternal-fetal medicine experts against midwives and other waterbirth proponents and leaving it up to the reader to decide which side is right. This March 23rd, an NPR article by Nancy Shute is a particularly frustrating example of weak medical reporting. In the article she essentially portrays giving birth underwater as an established and safe practice and medical experts as overly focused on a few flimsy anecdotes and case reports:

“Case reports are the lowest form of evidence,” Shaw-Battista counters. She is completing a study of 1,200 women who labored or birthed in water, and says they did as well or better than women who did not. “Given the bulk of the data, I don’t think we should use case reports to reject options that women are currently enjoying.”

Like many proponents, Shaw-Battista, who is the director of the Nurse-Midwifery Education Program at UCSF, touts unpublished data and subjective claims. About the only thing she says in the article that I can’t argue with is that if a family is going to deliver underwater it should be “conducted with a trained professional, be planned, and follow established guidelines.” I may not support the practice, but there absolutely should be somebody present who knows to get the baby out of the water right away without causing an avulsion of the umbilical cord, to not put the baby back in what amounts to sewer water for any reason, and who can perform neonatal resuscitation if necessary. That’s more likely to happen when a waterbirth takes place at a hospital or birthing center, which many do, but is decidedly less likely to be the case during a home birth, many of which are attended by laypersons with little to no experience in dealing with complications of any kind.

In the article, Shute also significantly misrepresents a 2009 (updated a bit in 2011) Cochrane review of immersion in water in labor and birth, and not just by calling it a 2012 review, which is when it was made available online:

A 2012 Cochrane review found no harm to the baby in 12 randomized controlled trials of water labor or birth involving 3,243 women, and less use of epidural anesthesia.

Yes, the Cochrane review looked at 12 studies, but 9 of them only involved immersion during the first stage of labor, which ends upon complete cervical dilation. The AAP and ACOG aren’t too worried about the first stage of labor other than the possibility that sitting in a tub of water might possibly interfere with providing appropriate emergency medical care in the event of a complication. They also ask nicely that facilities providing water immersion during the first stage of labor to please keep the tubs clean, however.

They admit that there may be some benefit in that there appears to be a little, and I mean a little, less use of spinal/epidural analgesia and that progression to the second stage of labor (delivery of baby but not the placenta) might move a little faster. It is questionable how clinically significant these benefits are however. And there is absolutely no evidence whatsoever that water immersion improves outcomes related to the baby. Only three of the studies used in the Cochrane review looked at the actual delivery, and they were unable to draw any conclusions regarding safety and efficacy.

A fine example of complementary and alternative reality in regards to labor and delivery can be found at Waterbirth International, which is run by >Barbara Harper, a nurse who preaches the benefits of waterbirthing all over the world and who is a proud proponent of rebirthing-breathwork. Rebirthing-breathwork is the concept that suppressed negative emotions can be healed by reliving one’s birth…and breathing a lot. Also there is something in there about cells having feelings. Harper gets the last word in the NPR article:

“I think this is backlash from the gaining popularity of water birth,” says Barbara Harper, founder of Waterbirth International, an advocacy organization…One thing that happens in a water birth, you as the attending physician pretty much have to stand there with your hands in your pockets and let it happen without your participation. That is pretty scary to a physician-oriented institution.”

How’s that for a straw man? Medical experts are apparently only skeptical of waterbirth because we don’t get to participate, which I have little doubt is code for “we don’t like it cause we don’t get paid.” I wonder if she works for free.

I believe that most rational people, even those with no medical experience, intuitively understand that delivering a baby into a body of water, even a sterile one, would be inherently risky. Human newborns, as with all other primates (take that Discovery Institute) breathe almost immediately upon arrival into this world. This helps to initiate a chain of events that assists the neonate in transitioning from fetal to adult circulatory patterns, and there are millions of years of evolutionary momentum behind this process. But besides being a completely unnatural act, something that usually sends proponents of pseudoscience running, there are numerous potential risks involved with giving birth underwater.

Before I discuss the risks, however, allow me to pass along the proposed benefits so that you might make an informed risk-versus-benefit determination for yourself. The following information comes from a Waterbirth International FAQ on the subject and is fairly representative of what other organizations claim and of the degree of misinformation patients are subjected to. Here is another example of information supportive of waterbirthing available online that goes much further, even implying that premature infants and other babies at high risk of complications, such as large babies at risk of becoming stuck at the shoulders during delivery, are good candidates. There is also a reference to the “aquatic ape” hypothesis hidden in there.

The most common proposed benefit of water labor and birth is less pain, and therefore a better chance of achieving a “natural” childbirth without drugs for maternal comfort. This desire for a drug-free childbirth is based on the naturalistic fallacy, misleading claims of risk by proponents, a large helping of misogyny, and dubious ethics on the part of medical professionals who would otherwise never allow a patient to suffer. Other more objective claims are that it speeds up labor, decreases the need for C-sections, and reduces the number of trauma-requiring interventions. Proponents also claim that decreased maternal stress hormones are better for the baby, and that the newborn transition will be gentler which just has to be a good thing. The rest are entirely subjective, such as increased relaxation, improved sense of well-being and control, or involve how satisfied the mother was with the process.

So what kind of evidence base supports these claims of benefit? According to the recent statement from the AAP and ACOG, and I’m paraphrasing a bit, it ain’t good. The following quote works too:

Most published articles that recommend underwater births are retrospective reviews of a single center experience, observational studies using historical controls, or personal opinions and testimonials, often in publications that are not peer reviewed.

The authors also point out that there is a complete absence of any basic science, in either animals or humans, to support the proposed physiologic benefits of giving birth to a human underwater. Plenty for fish though.

Another huge problem with the evidence for water labor and birthing, whether published in peer reviewed journals or anecdotes on websites and documentaries, is the lack of consistent definitions. What defines water labor and waterbirth varies from situation to situation and between institutions. Timing, temperature, maternal health problems and location can vary significantly. And I’ve already given you an example of a so-called science reporter conflating safety data from just labor with safety of underwater birth, which is at the very least extremely misleading, and potentially dangerous. There is also a complete lack of blinding and virtually no controlling for the other aspects of the birthing environment when comparing standard to underwater deliveries.

What does the available evidence support after taking into account the poor quality of available data? Not a whole lot. As I stated earlier, there appears to be a modest, though perhaps not clinically significant, decrease in the use of pain-reducing procedures. There also appears to be a decrease of about half an hour in the time it takes for labor to progress to full dilation, but again this is hampered by a lack of controlling for potential confounders. There is no good data to support a difference in delivery-associated trauma, the need for vacuum or forceps assistance, or the need for a C-section. There is no evidence to support claims of benefit to the newborn. But it does seems that mothers are more satisfied with delivery underwater, which may only be a result of theatrical placebo employed by waterbirth attendants.

Now that I hope I’ve made it clear just how flimsy the case for giving birth underwater is, it is time to discuss the potential risks. Similar to the data held up by proponents as supportive of their claims of benefit, the risk of underwater birth is largely based on individual case reports and series, although the basic science foundation is solid. This means I can’t tell you how common it is for these complications to arise, but of course the burden of proof does fall on the proponents to show benefit. That being said, the risks that have been reported can be quite serious, even deadly. I’ll just list them:

  1. Increased risk of infection, especially after rupture of the membranes acting as a barrier between baby and the outside world
  2. Problems with temperature regulation in the baby
  3. Damage to the umbilical cord, or pulling of the cord out of the placenta, leading to severe bleeding complications
  4. Respiratory distress, hyponatremia, seizures and asphyxia from fresh water drowning

These risks, although rare, are potentially catastrophic. There are numerous case reports/series of deaths and significant morbidity. One study that was not included in the Cochrane review because it involved a comparison of standard delivery and waterbirth of infants with dystocia (abnormal or difficult childbirth/labor) showed that 12% of the babies born underwater required NICU admission while none of the babies born dry, relatively speaking, did. The only variable in a delivery that can lead to fresh water drowning, for instance, is the choice to have a waterbirth. That alone, in my opinion, is enough to establish that at this time the risk outweighs the benefit. The incidence of these adverse outcomes is likely much higher when an infant with risk factors is born underwater. Essentially the same issues that come up with home births in general are exacerbated by adding water.

Why don’t babies breathe when they are born underwater? According to Barbara Harper, there are many reasons, including that God doesn’t want them to, but four that stand out:

1. Prostaglandin E2 levels from the placenta which cause a slowing down or stopping of the fetal breathing movements. When the baby is born and the Prostaglandin level is still high, the baby’s muscles for breathing simply don’t work, thus engaging the first inhibitory response.

Healthy babies born without difficulty typically breathe within ten seconds of birth, but many breathe right away. The likely reason that there isn’t a higher incidence of aspiration of water after delivery is that the standard approach is for the attendant to remove the baby from the water right away, though with care to not damage the umbilical cord. A sick baby may have already begun gasping breaths while still in the womb, and they often pass stool prior to delivery which can be aspirated and cause a great deal of morbidity and mortality. If a sick baby were to be born into water, they are almost certainly at increased risk of drowning.

2. All babies are born experiencing mild hypoxia or lack of oxygen. Hypoxia causes apnea and swallowing, not breathing or gasping.

This demonstrates a complete misunderstanding of newborn physiology around the time of birth. Yes, oxygen saturation levels in newborn babies are not 100%. They slowly rise over the first several minutes of life to normal levels. So this is true in that sense. In regards to apnea, I can only assume that she means primary apnea. This occurs when an infant is unable to achieve adequate oxygenation through breathing once the placental supply of oxygen is diminished. It is never normal for a newborn to be apneic, but it is somewhat common.

Primary apnea, when it occurs, often responds to simple stimulation to breathe as occurs during drying and providing a clear airway, while secondary apnea, which occurs after a prolonged lack of oxygen delivery to the brain, requires more aggressive resuscitation. Again, babies typically breathe within a few seconds of birth. So the attendant at a water delivery must quickly retrieve them from the water. I’m sure they make it seem like a gentle and loving thing, but as soon as the kid hits the water, the clock is ticking and such a nonchalant reference to apneic newborns is frightening.

3. Fetal lungs are already filled with fluid. That fluid is there to protect the lungs, and keep the spaces open that will eventually exchange carbon dioxide and oxygen. It is very difficult, if not improbable, for fluids from the birth tub to pass into those spaces that are already filled with fluid. One physiologist states that “the viscosity of the fluid naturally occurring in the lungs is so thick that it would be nearly impossible for any other fluids to enter.

This is true, prenatally. But the onset of labor signals a surge of chemicals called catecholamines that signal the lungs to quickly reabsorb fluid. This is why babies that are born without labor, such as via a scheduled C-section, often have a transient period of fast breathing related to some retained fluid in the lungs. The lungs are not “filled with fluid” at the time of delivery however, and will readily accept a bolus of fresh water as has been reported many times. In fact, premature infants, and sometimes even those delivered at term, often have medicines purposefully squirted into the lungs via an endotrachial tube right after birth. They get in there just fine.

4. The last important inhibitory factor is the Dive Reflex and revolves around the larynx. The larynx is covered all over with chemoreceptors or taste buds. The larynx has five times as many as [sic] taste buds as the whole surface of the tongue. So, when a solution hits the back of the throat, passing the larynx, the taste buds interprets [sic] what substance it is and the glottis automatically closes and the solution is then swallowed, not inhaled.

The dive reflex occurs in aquatic mammals primarily but there is a weaker version in humans. It involves a reduction in heart rate and a shunting of blood from the peripheral vasculature to the vital organs, primarily the heart and brain, allowing for an extended duration of breath holding. This reduction in heart rate can actually sometimes be put to medical use in young patients presenting with one type of arrhythmia called supraventricular tachycardia. We hold a bag of ice water over the entirety of their face. Strange but true.

The dive reflex only occurs when the face is submerged in very cold water. Breath holding associated with submersion in cold water is an involuntary process where breathing is centrally inhibited. What waterbirth proponents are confusing the dive reflex with here is drowning. During drowning, when water hits the airway there is spasm of the surrounding musculature and closure of the epiglottis. This prevents aspiration and forces swallowing of the water, which is why there is risk of hyponatremia in fresh water drowning. Eventually the spasm will relax and water will be taken into the lungs.

These are the people delivering our babies. When waterbirths take place in cold water, which they never do because that would interfere with the pleasurable experience of the mother, they can talk about the diving reflex. Or if they are delivering a seal. You know what really interferes with the pleasurable experience of the mother? A dead baby.

One final time, the reason why more babies don’t tend to aspirate water after a waterbirth is timing and luck. They are retrieved prior to the first breath, which may be a little delayed because of reduced stimulation to a baby born underwater. It is as simple as that. Some babies will always breathe too soon. Sick babies are more likely to breathe too soon. If a baby develops primary apnea, and stimulation to breathe is delayed because they are underwater, their heart rate will plummet and prolonged lack of oxygen to the brain will lead to them requiring substantial resuscitation.

Final thoughts

The conclusion of the AAP/ACOG statement that has waterbirth proponents so bent out of shape is extremely well-reasoned. They admit that water immersion during the first stage of labor might have some very limited benefit as discussed above. But they stress that there isn’t evidence to support improved perinatal outcomes, and that if a mother chooses to relax in a pool filled with water it shouldn’t get in the way of other aspects of appropriate care. Of course lay midwives attending a home waterbirth might have a different opinion regarding what those are.

In regards to actually delivering in the water, the authors conclude that the safety and efficacy is not established. They state, based on the many case reports of severe complications and lack of quality evidence to support maternal or fetal benefit, that any underwater deliveries should be considered an experimental procedure and take place in the context of a clinical trial with informed consent. And there is the rub. I have grave concerns that appropriate informed consent is currently not being obtained, that the benefits are overhyped and the risks downplayed beyond what is supported by the evidence. A lack of proper informed consent violates one of the four foundational principles of medical ethics, which is a respect for the patient’s personal autonomy.

There are few things as intimate and emotionally powerful as the process of giving birth. The variables inherent in this process range from the fairly minor, such as what music a mother would like to listen to during labor, to the extremely important choices of where and how the baby is to be born and who is to be in attendance at the delivery. Many of these choices have relatively little if any impact on the health of the newborn baby or on the risk of maternal complications, but rather help to mold and shape the overall experience of childbirth to the mother’s liking. Regardless of the importance of each choice, it should come as no surprise that they are as subject to personal biases, logical fallacies, and social and cultural influences as any other decision.

Expectant mothers, and often their families, put a great deal of focus on the subjective experience of childbirth, and this is understandable as the memories being forged will last a lifetime. There is unfortunately, for many families, an idealized perfect labor and delivery experience that often appears to be based more on television and movie portrayals or the anecdotes of friends than on explanations by science-based healthcare professionals. But sometimes this ideal experience is molded and shaped by biased healthcare professionals employing motivated reasoning, or by nonprofessional lay practitioners who hold themselves up as birthing experts.

They all likely mean well and want what is best for the mother and baby, but that is not an excuse. Childbirth is a time of great vulnerability. All parents want their children to enter the world happy and healthy, and to stay that way as they grow. Unfortunately, when this all-too-human desire to have a positive birth experience and a healthy baby is hijacked by excessive worry based on false or misleading information, people can make uninformed and potentially deadly decisions. My provisional conclusion is that choosing to deliver a baby underwater is such a decision. If proponents are at some point able to present good evidence to show that the benefit of waterbirth outweighs the risk, I will gladly change my opinion.

-Here is a nice discussion published in Pediatrics in 2004, titled “Water Births: A Naked Emperor.” Here is the midwife response and subsequent destruction of that response by Dr. Schroeter.

-Dr. Jen Gunter, an evidence-based OB/GYN and pain medicine physician, also recently discussed the AAP/ACOG statement on her website. She agrees that introducing water to the birthing mix shouldn’t get a free ride.

-Finally, here is a satirical look at the extremes people go to in an effort to have a memorable birthing experience.


  • Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.

Posted by Clay Jones

Clay Jones, M.D. is a pediatrician and a regular contributor to the Science-Based Medicine blog. He primarily cares for healthy newborns and hospitalized children, and devotes his full time to educating pediatric residents and medical students. Dr. Jones first became aware of and interested in the incursion of pseudoscience into his chosen profession while completing his pediatric residency at Vanderbilt Children’s Hospital a decade ago. He has since focused his efforts on teaching the application of critical thinking and scientific skepticism to the practice of pediatric medicine. Dr. Jones has no conflicts of interest to disclose and no ties to the pharmaceutical industry. He can be found on Twitter as @SBMPediatrics and is the co-host of The Prism Podcast with fellow SBM contributor Grant Ritchey. The comments expressed by Dr. Jones are his own and do not represent the views or opinions of Newton-Wellesley Hospital or its administration.