Nitrous Oxide for Laboring Women in the United States

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By Jill

I wrote an article for RH Reality Check last month on the roadblocks faced by those working to make nitrous oxide available to laboring women in the United States. Please click over to read the full story if you haven’t read it already. May this excerpt entice you to do so:

Twenty-five years ago, Evan McAllister tried to bring Entonox, a premixed gas blend consisting of 50 percent nitrous oxide and 50 percent oxygen from the U.K. to the United States under the name Dolonox. McAllister, a respiratory therapist with a background in anesthesiology, hit a roadblock with the Food and Drug Administration, who denied the application for what he calls “compliance reasons.”

The U.S. FDA grandfathered in older medical gases, including nitrous oxide and oxygen shortly after the turn of the century. A blend of these two medical gases is treated as a new drug, which requires extensive (and expensive) research to be approved.

Determined to make nitrous oxide available in the U.S., McAllister designed a device to blend pure oxygen with pure nitrous that could be self-administered by the patient. The device was in production until about 20 years ago, when sales dropped off and McAllister stopped making them.

As a result of recent interest in nitrous oxide as a labor analgesic, McAllister and his company, Nitrox, Inc., designed a more compact version of the decades old blending unit, which they are actively marketing.

Said McAllister, “I’ve had it all shut down for 25 years and it’s all coming back.”


When I posted a link to the article on our Facebook page, it received a mixed reaction, including a handful of people concerned about “more drugs” and the idea that there would be another tool that could be used by hospitals to keep women complacent. Although we did just read that some health care professionals consider one of the advantages of epidural anesthesia to be that it facilitates patient cooperation during delivery, there seems to be an assumption by a few that women never opt for anesthesia or narcotics with full agency. A few thoughts:


It could only be ideologically or symbolically administered without full agency (to answer critics mentioned above), as successful administration of nitrous oxide depends on self-administration.


The 50/50 mixture of N2O with oxygen used in hospitals is eliminated through the lungs, not the liver, making it a safe option for mother and baby if self-administered properly


Women in countries that offer nitrous oxide (“gas and air”) routinely at both hospital and home births find it absolutely bizarre that the option is not available in the United States.


Nitrous oxide is a medical gas that can be discontinued as quickly and easily as it is started. The effects are completely gone within five minutes.


It is an analgesic, not anesthesia. Women for whom it works well report that the pain is still there, but they just don’t care. I made a fresh Wong Baker pain scale to demonstrate.


For women who are planning or open to epidural anesthesia but learn that it is contraindicated due to any number of conditions, such as “active maternal hemorrhage, septicemia, infection at or near the site of needle insertion and clinical signs of coagulopathy,” nitrous oxide is a safe, humane option to take an edge off the pain of labor and any related procedures. It should be one of MANY analgesic and pain-reducing tools (including non-pharmacological options) available to women in U.S. hospitals.

As Judith Rooks wrote in the Journal of Midwifery & Women’s Health in 2007, “[i]t is particularly helpful for women experiencing rapid labor, transition, second-stage labor, and while suturing the perineum. It can be extremely helpful for women who want to avoid an epidural, useful for women who have to wait for an epidural, and a blessing for everyone when there is a sudden, unexpected need for analgesia for an invasive procedure required because of an obstetric emergency.”


Readers of The Unnecesarean who wanted an epidural but couldn’t get one or had an ineffective epidural took a moment to share their experiences.

My second labor advanced so quickly that I narrowly missed delivering at home - arriving at the hospital via ambulance, the L&D staff took one look at me and said, “OK, on the next one you’re going to push.” I thought they were crazy — but those simple words cemented the fact that I was about to have an unmedicated VBAC (it lasted another hour and also included a case of shoulder dystocia relieved by the McRoberts maneuver….. and then manual removal of the placenta another 40 minute later).

Given the unpredictability of labor (how could I have known my second would be a 2-hour labor?!), I would heartily endorse the availability and use of nitrous oxide to expectant women — certainly, in my own condition or precipitous labor, any kind of pain relief would have afforded me some respite - emotionally as well as physically. I wish I had had the option in 2007.




You asked about epidurals… with baby #1, I had an epidural. They later decided I needed a c-section, but they needed to top off the anesthesia. The anesthesiologist was nowhere to be found. I was strapped to the table in the OR, arms out and legs together. The epidural wore off and I had to push. No one was in the room with me that I could see… no one responded to me at all. After about a half hour, they finally found the anesthesiologist to come in and redo the anesthesia so they could do surgery. I am betting at that point, I could have pushed my baby out.

With baby #4, I had little support. Hubby was exhausted and my doula was napping. I was feeling sorry for myself for being on my own, and talked myself into an intrathecal. By the time the anesthesiologist could get to me, however, I was beginning to push, so ended up having nothing at all. It was definitely for the best, but at the time I was really ticked when he turned around and walked back out. 

If nitrous oxide had been available when I had hospital births, I would probably have opted to use it. I’ve had it at the dentist, so I know the effects it has on a person. While I have only read a little bit about nitrous oxide during labor, I would imagine that since it clears from the body so quickly, it might be a very good option for women who need some pain relief. 




Well, I do want to say I was going for a homebirth the first time, but got severe pre-e, had two days of induced labor, and then asked for an epidural. I couldn’t get one because my platelets were too low. So, I had my unnecesarean with general anesthesia. For that particular birth, I would have liked to have that option, and would have used it. I think the option should be available, but I wouldn’t use it unless I found myself in the hospital again with a labor and birth like my first. 




I requested an epidural (was trying for a natural birth, but ended up needing pitocin due to ruptured waters and not going into labor naturally, and I couldn’t deal with those horrible contractions anymore), but the anesthesiologist couldn’t get the catheter in the correct spot. He tried twice. I only went sorta numb on my left side. I sat curled up in the most horrible position imaginable to me for about 40 minutes while he worked, all for nothing. And now I have back problems (don’t know if they’re related or not, but I have read about many women complaining with back pain after). I hope that if there’s a next time, the pain won’t cloud my memories of what a horrible experience that was, and I’ll refrain from requesting one again. Besides, I’d like another water birth!




I actually stated in my birth plan that before anything else (narcotic, epidural) I wanted to try nitrous. I had no idea it wasn’t offered to laboring women in the US, and I was very disappointed when my doctor told me this. I received laughing gas for my dislocated patella (this was the same incident I was describing where I received Demerol, as well) and it controlled my pain pretty well. I would much MUCH prefer having nitrous over narcotic, as I have read it has little to no affect on the baby, and as I said, it works pretty well for pain management. 




With my first baby, I was at the hospital in time, but by the time I thought about anesthesia, it was “too late.”  I had a very fast labor, and I went from 5-7 in a couple hours, but about 15 minutes after I was at 7, I started to panic.  I figured there was no way I could do it.  I asked the nurse, and my hospital doesn’t do anesthesia after 7 cm.  Turns out the reason I was panicked is that I was at 9 with a little lip.  Had I known that I would have not been nearly as panicky or scared, but I assumed I still had a few more hours of the same intensity in order to have my baby.




9 cm when I got to hospital.  Had no idea i was that far along because my bag hadn’t broken so the counter pressure of the fluid against the cx’s kept them manageable (or at least that’s what I attribute it to).  This was well before I was a doula or knew anything about natural childbirth.  However, I had had an epi-free birth 10 years before.  I wasn’t prepared this time and didn’t know that I really had ‘planned’ on anything.  But when my water broke (as the doc was checking to confirm 9cm), he told me it was too late for any pain meds.  I guess I freaked because I had no idea I was that close - I thought I had time.  The panic and the water breaking really intensified the cx’s and I just lost it over not being able to have meds.  Truly didn’t have time though because I was pushing within 10 minutes




With my first, I was induced for pre-eclampsia. The doctor ORDERED an epidural against my request. Once the first epidural was in place, my pitocin was maxed out, about 20 minutes later the epidural wore off, they had put it in the wrong place. I was in an off-the-charts contraction for 45 minutes before they could get another one in place. Epidural #2 worked, and after the threat of a c-section, my son was born after 5 sets of pushes and the stupid doctor barely made it in the room to catch him (literally).  I despised my OB, still do. So, I have a new one! Ha!




My second was an “unnecesarean”. Everything had been fine, except I had some high blood pressures again, ended up with pre-e again. At about 32wks she started measuring large via U/S. They sent me to a specialist, there too she was measuring very large and I had excess amniotic fluid. The specialist attempted to diagnose me with gestational diabetes. My first GTT was slightly elevated, due to eating McDonald’s and having a huge sweet tea a few hours before having to take it. I took another 1hr, then two 3hrs, all normal. (I have since been told by an endocrinologist I was not and have not ever been diabetic, despite the specialists “diagnosis”).  My daughter measured 10lbs 11oz via ultrasound. I knew u/s measurements were inaccurate, as my son was 9lbs 9oz on u/s two days before he was born at 7lbs 8oz. My doctor pushed for a csection, and despite a midwife telling me I could have her vaginally (i didn’t believe her..i mean the doctor was saying I couldn’t…….I know better now). The c-section was scheduled. I went in for my labs and the nurse took my BP, it was crazy, like 160/110, she called the doc and he said I was fine, but she told me to be sure to check it in the am. So, it was Tues, I checked it and got crazy again, 175/125. I went to the office, they took it then quickly shooed me to the hospital “before I had a seizure and became a vegetable in the office” is what I was told…….NICE.  I told them I needed general anesthesia because my last epidural didn’t work, I was extremely afraid that it would wear off. They tried, I don’t know how many times, one time included a medication to see if it was in the proper place that sent me into full body convulsions for 20 minutes. They ended up doing a spinal, which still scared me to death. The doctor pinched me with something and said “Can you feel that? I’m pinching the crap out of you!”  The medication went mostly down, but alot up and I ended up throwing up. That was interesting…… I don’t remember her being born because I was so loopy.



Related reading:

Minimizing the Negative Effects of Epidural Anesthesia

American College of Nurse Midwives Position Paper on Nitrous Oxide for Labor Analgesia