Why We Avoid General Anesthesia for Birth, And When It Becomes the Safest Choice
Anesthesia and Birth: What Actually Happens - Part 3
Throughout my time as a CRNA, the scariest moments have all involved the same thing: not being able to deliver oxygen or secure an airway quickly enough.
One patient still sticks with me. We were trying to intubate a woman who had been laboring for three days. We tried to strengthen her epidural for surgery, but it didn't work, and we had to move quickly to general anesthesia. Her airway was swollen from prolonged labor and fluid shifts. I got the tube in, the baby was delivered, everyone was okay—but it was close.
Labor and delivery is one of the most dynamic areas of anesthesia. And I have so much respect for the anesthesia professionals who do this work.
Even when the plan is a spinal. Even when the epidural should work. Even when the patient is awake, talking, and breathing on their own. We still have to be ready to convert to general anesthesia at any moment.
Most of the time, we will not need to.
But when we do, the situation often changes quickly. And in obstetrics, “quickly” can mean there is very little time to troubleshoot, deliberate, or slowly build a new plan. The team has to move with precision because now we are caring for two patients at once: the person giving birth and the baby who needs to be delivered safely.
For the women I know who have needed general anesthesia for an emergency C-section, it is often frightening and disorienting on top of an already intense experience. One moment they are awake and aware, and then suddenly the room changes. People move faster, and medications are given quickly. We are often literally running down the hall (one of the only times we actually do that, despite how often they show it happening in the TV shows).
The whole experience can be very traumatic, even when it ends with a safe delivery and a healthy baby.
So in this part, I want to explain what general anesthesia for a C-section actually means, why we try to avoid it when we can, and why sometimes it becomes the safest choice.
This is Part 3 of a 4-part series on anesthesia and childbirth. In Part 1, I covered epidurals for labor. In Part 2, spinals for C-sections. Today: general anesthesia for birth—when we use it, why we try to avoid it when we can, and what actually happens when it becomes necessary. If you have questions, drop them in the comments—I’ll answer them in Part 4.
Why We Avoid General Anesthesia When We Can
The simple answer is: because a spinal or epidural usually allows us to avoid the highest-risk parts of general anesthesia in pregnancy.
With a spinal or epidural, you can stay awake, breathe on your own, protect your own airway, and still have complete surgical numbness. That is why neuraxial anesthesia — meaning spinal, epidural, or combined spinal-epidural anesthesia — is the preferred approach for most C-sections. That is also why spinals and epidurals are used for more than 95% of elective and even 80% of emergent C-section deliveries in the US.
That does not mean general anesthesia is wrong. It means we use it when the benefits outweigh the risks.
And in pregnancy, the risks are different.
The First Concern: The Airway
Pregnant patients are not just “regular anesthesia patients who happen to be pregnant.” Pregnancy changes the body in ways that matter deeply for anesthesia, especially when we are talking about general anesthesia and the airway.
By the end of pregnancy, the airway (like most other parts of the body due to the dramatic increase in blood volume) becomes swollen. The tissues in the mouth, nose, throat, and around the vocal cords can also become more vascular, meaning they may bleed more easily if they are irritated. Even small amounts of swelling or bleeding can matter when we are trying to place a breathing tube quickly and safely.
Positioning can also be more difficult. The enlarged abdomen changes how the body lies on the operating room table, and the breasts can make it harder to position the laryngoscope, which is the instrument used to help place the breathing tube. These small details are critical in airway management.
Pregnant patients use more oxygen, but they also have less reserve in their lungs because the enlarged uterus pushes up on the diaphragm and reduces functional residual capacity, which is essentially the amount of air left in the lungs after a normal breath. So once a pregnant patient is asleep and not breathing on their own, oxygen levels can fall faster than if they were not pregnant.
The Second Concern: Aspiration
Aspiration means stomach contents come back up and enter the lungs. This can cause serious lung irritation, difficulty breathing, pneumonia, or even life-threatening lung injury. It is one of the reasons anesthesia providers ask so many questions about when you last ate or drank, whether you feel nauseated, and whether you have reflux.
It is also one of the reasons many hospitals limit what you can eat during labor.
The concern is what might happen if labor suddenly becomes an urgent C-section and general anesthesia is needed. Once someone is under general anesthesia, they lose the normal protective reflexes that help keep stomach contents out of the lungs.
Pregnancy and labor increase this risk. The enlarged uterus pushes up on the stomach. Labor pain, stress, and opioid medications can slow stomach emptying even further.
This is why anesthesia guidance generally allows modest amounts of clear liquids for uncomplicated laboring patients, but recommends avoiding solid foods during labor. For scheduled C-sections, patients are typically asked to fast from solid foods for 6–8 hours, depending on the type of food, and clear liquids may usually be allowed until about 2 hours before anesthesia.
The Third Concern: The Baby
General anesthesia medications can cross the placenta. The longer the time between starting general anesthesia and delivery, the more the baby is exposed to those medications.
Recent research shows that babies born by C-section under spinal or epidural anesthesia, or combined spinal-epidural anesthesia, tend to do slightly better in the first few minutes after birth compared to babies born under general anesthesia.
A recent meta-analysis found that spinal or epidural anesthesia was associated with slightly higher Apgar Scores1 (a measure of how well the baby is doing right after birth) and less need for breathing support right away. However, the rates of babies needing NICU admission were about the same.
General anesthesia is often used in the sickest, fastest-moving, most urgent cases. It may be used when there is fetal distress, severe bleeding, maternal instability, a failed epidural or spinal, or simply not enough time to safely place neuraxial anesthesia.
So, when we see a study on worse neonatal outcomes associated with general anesthesia, we should be mindful of a hidden variable: part of the retrospective relationship may be related to anesthesia exposure, but there may also be other causes, like the reasons the general anesthesia was needed in the first place.
When we can safely avoid it, we usually prefer to. Regional anesthesia lets us avoid airway manipulation, reduce aspiration risk, keep the mother awake and breathing on her own, and may also be associated with a modestly better early newborn transition.
The Fourth Concern: The Birth Experience
When you have a spinal or epidural for a C-section, you are awake. You may feel pressure, pulling, tugging, and movement, but you are present. You can hear the baby cry. You can usually have a support person in the room. You can remember the birth.
With general anesthesia, that changes.
You are unconscious. A breathing tube is placed. Your support person may not be allowed in the operating room, depending on the urgency and hospital policy. Your first memory may be waking up in recovery and being told the baby has already been born.
For some people, especially when general anesthesia happens during an emergency, that can be emotionally difficult. A recent review found that general-anesthetic cesarean birth can affect maternal mental health, childbirth experience, and bonding, although the research base is still limited.
We need to be doing more research on these experiences and developing interventions to help women through these types of experiences.
Why We Prepare So Carefully
Every C-section has an anesthesia plan. But it also has a backup plan. And a backup plan to the backup plan. That is especially true in pregnancy because things can change quickly.
And that is what I wish more people understood about anesthesia for birth. It is not just about being awake or asleep. It is not just about spinal versus epidural versus general anesthesia. It is about constantly balancing risks in real time while caring for two patients at once.
The best anesthetic is not always the one we hoped to use when the day started.
The best anesthetic is the one that keeps a patient and her baby safe when the moment changes.
Next week: Part 4 of Anesthesia and Birth—Your questions answered. Hot topics, complications, and everything else you’ve been wondering about.
Got questions about general anesthesia, spinals, epidurals, or anything else in this series? Drop them in the comments. I’ll answer them in Part 4.
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For an interesting read on Apgar Scores, check out the relevant chapter in Atul Gawande’s modern classic The Checklist Manifesto (2009)! For a book about this topic, Virginia Apgar’s Is My Baby Alright? (1972) is also an incredible read.
Great overview of airway management in pregnancy!
The physiology is always interesting and challenging.
An added layer I try to impress on my residents- in pregnancy the goal oxygen saturation > 95% to avoid any fetal hypoxia, as opposed to most adults we are ok with 89%+.