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Nitrous Oxide in Labor and the Precautionary Principle

An increasing number of hospitals in the United States have begun offering nitrous oxide to women in labor since the FDA approved new equipment for use in labor in 2011. In the Boston area where I am, Brigham and Women’s Hospital started offering it nearly two years ago, and then other hospitals, including South Shore, Emerson, Wentworth-Douglas, Exeter, St. Joseph, and Newton Wellesley, scrambled to offer it as well. Among other things, a hospital is a business competing with neighboring hospitals for customers. If they get you to come there to birth, you could become a lifelong customer. You’ll know when nitrous comes to a hospital near you because your local paper will feature an article about it, prompted by a hospital press release, in which smiling women hold their babies and rave about how much they enjoyed using it in labor.

Doulas and childbirth educators who are seeking answers to their clients and students questions, are looking for information on Facebook. The attitude towards nitrous is overwhelmingly positive in the discussions I’ve seen. Most seem to be comparing it favorably to epidurals. But if we don’t ask the right questions, we won’t get the right answers. If we ask does nitrous oxide cause epidural fever, a drop in blood pressure, or the need for urinary catheterization, and then go away satisfied because the answers to the questions are no, we have failed the families who depend on us for information and support. It is impossible for them to make informed decisions in the absence of information. In this pro-nitrous piece, Judith Rook sums it up when she says, “The major benefits (of nitrous) are mainly lack of disadvantages associated with relying on epidurals, opioids and nonpharmacologic methods to relieve and help women cope with pain during labor.”

Women and their birth partners need a toolkit filled with contraction rituals and support techniques as they prepare for labor. If we describe these skills by labeling them as what they are not, as Judith does above (they are not pharmacologic) we are revealing our bias. Just as if we say un-circumcised we show that we our starting point is the circumcised penis, or if we say out of hospital births, we are showing that we see hospital birth as the norm. It is important to remember that when we look at these issues globally or historically we see that hospital birth, circumcision, and pain meds in labor are in fact not the norm. The healthiest birth for mother and baby is usually the one in which no medications are used. This is made more achievable when birthing women educate themselves prenatally about techniques for labor, and surround themselves with supporters who know and trust normal birth, and are skilled in labor support techniques. It is easier when women are eating and drinking in labor, can move to follow their bodies’ cues, have the option of laboring in water, are not continuously monitored, etc.

It’s not a perfect analogy, but please bear with me. Your teenager is invited to a party where you know there will be drinking. You discuss the risks of drinking with him or her. Then your kid discovers there’s an alternative to drinking at this party, some kids will be smoking cigarettes instead! So you compare drinking with smoking. The risk of alcohol poisoning is zero when smoking cigarettes! Smoking cigarettes does not increase the risk of being sexually assaulted! Driving after smoking cigarettes is not illegal! Would you therefore conclude that your child should start smoking? If we don’t ask the right questions, we will not get the right answers.

Now is a time for first do no harm, critical thinking, and the precautionary principle. Remember the precautionary principle? It’s the idea that new drugs, food additives, cleaning chemicals, fire retardants on children’s sleepwear, baby powder, plastics in baby bottles, etc., should be treated as guilty (unsafe) until proven innocent (safe). This idea is echoed in the “First do no harm” oath that doctors take. When I’ve raised the precautionary principle in Facebook discussions about nitrous, my concerns are dismissed because they’ve been using it for generations in Europe. Nitrous is the gas and air you see moms inhaling in 1950s London on the tv show Call the Midwife. Does that prove that it’s safe?

One of the known risks of nitrous oxide is that it depletes the body of vitamin B12. Hospital policy will usually say that its use is contraindicated in mothers with low B12. However, health care providers are not routinely testing B12 levels of pregnant women, nor are labor and delivery nurses required to ask if women know if they have low levels of B12. I talked with a women who gave birth to a baby in Europe. Afterwards, she suffered from depression and her baby was failure to thrive. When she weaned her baby to formula, he improved. Eventually her low B12 levels were discovered and she was able to be treated and feel better. She had nitrous in her labor, but had never connected the dots. What if instead of asking does nitrous cause epidural fever, we ask does it increase the risk of postpartum depression or failure to thrive in breastfed babies? Have you read Kelly Brogan’s new book, A Mind of Your Own? She describes a case of severe depression that was cured by remedying the B12 deficiency.

Who is at risk for low B12? Vegetarians and vegans without proper supplementation are, and that is widely known. Stress depletes B vitamins. So does impaired digestion, so anyone with leaky gut, a history of antibiotic, antacid or NSAID use, Chrohn’s disease, diabetes, pernicious anemia, gastric bypass surgery, a diet high in GMOs, or a thyroid disorder is at risk. It also includes anyone with impaired methylation. About 40% of the population has one or more mutations of their MTHFR gene, a gene involved with methylation, which may put them at increased risk for low B12. When my childbirth students ask about nitrous, I ask them what their vitamin B levels are and if they have a MTHFR mutation. I am usually met with a quizzical expression. Most providers are not explaining this in prenatal appointments.

I would suggest that many, perhaps most, pregnant women in the United States have at least one of the risk factors above. We know that pregnancy is a risk factor for thyroid disorders and stress. I see some of my pregnant childbirth students taking Tums like candy and eating packaged foods out of the vending machine. And 30% of them will test positive for beta strep and receive iv antibiotics in labor. That is because in the United States doctors take a universal approach, and recommend antibiotics for all women who are GBS. In the United Kingdom, doctors take a risk-based approach, and recommend antibiotics for GBS women only when they have specific risk factors such as premature labor, a fever, prolonged rupture of membranes, a previous baby with GBS, or GBS in their urine. So while women in the UK have been using nitrous for generations, they don’t use antibiotics in labor as often, which would be an additional risk factor. Additionally, there are no GMO crops grown in the UK. While GMO food is imported, British women are likely eating less GMOs than American women. Most British women not drinking fluoridated water, while most American women are. Are there other differences as well that would also help them to have higher B12 levels going into their labors, and a greater ability to restore proper levels after nitrous use?

If you want to learn more about the effects of nitrous on the 40% of the population with MTHFR mutations, check out this study. Please note that for ethical and legal reasons, pregnant women were specifically excluded. It’s not considered ethical to enroll them in a study on the effects of nitrous, but it is legal to encourage them to use it in labor. Dr. Ben Lynch, an expert on MTHFR, considers all women who are pregnant or breastfeeding to be at risk for B12 deficiency, even when they have no other risk factors. Read his informative article about nitrous.

As a childbirth educator and doula I see a large part of my job to be providing my families with accurate information so they can do their job, make informed decisions. Without information, informed decisions are impossible. Studies on the use of nitrous on laboring women may be years away. But t is vital that we educate ourselves about what is currently known about nitrous as it becomes increasing available to the women we serve. And in the absence of adequate information, let’s start with the precautionary principle.

Julie Brill, CCCE, CLD has taught childbirth education to thousands of families over the last twenty-four years and has mentored hundreds of doulas and childbirth educators since 2003. She is the mother of two teenage girls, a La Leche League Leader, and the author of the doula anthology Round the Circle: Doulas Share Their Experiences.