Do Epidurals Always Work?

If you are pregnant and approaching your due date, then you may be wondering about your options for pain control during labor. For pain relief during labor, many choose to get an epidural, or spinal anesthesia. But you may know someone who didn’t get adequate pain relief with their epidural or had other issues with it. Here we'll review how epidurals work, why sometimes they might not, and other options for pain management during labor.

How does an epidural work?

An epidural is the most common type of pain control used during labor. It involves placing a needle into your lower back to guide a small tube, called a “catheter,” into the epidural space.  This is the area around the lower part of your spinal cord. The next step is to remove the needle while leaving the catheter in the epidural space. Pain medication is then injected through the catheter to numb you from the waist down.  

Once the medication takes effect, it will take away your contraction pain. The catheter is left in place so you can get more pain medication when the first dose wears off. Though an epidural relieves your pain, you will still be able to feel pressure. This is important because feeling pressure will help you push when it's time to do so. 

Are there any risks to getting an epidural?

Epidurals are safe for you and your baby. The amount of medication that reaches the baby from the epidural is very small. There’s no evidence to suggest it can harm the baby. 

But there are some side effects and risks that may occur when getting an epidural. Some of the more common ones include:

• Drop in blood pressure: The medication used in the epidural may lower your blood pressure. This can lead to a decrease in your baby’s heart rate. These are usually temporary side effects that extra intravenous (IV) fluids can quickly correct. If IV fluids aren’t enough to fix the problem, your provider can use other medications to help bring your pressure back up.  

• Headache: You might get a headache if some of the fluid from your spine leaks out when you get an epidural. These types of headaches usually last for a few days after delivery.

• Difficulty urinating: Sometimes it takes a while to be able to urinate on your own after getting an epidural. This happens because the epidural also numbs the muscles in your bladder, so you don’t feel the urge to go. This is also a temporary side effect that often corrects within a few hours after the epidural wears off.

• Back pain: The area where the catheter was inserted may be sore for a few days after your epidural.  

Will it slow down my labor or lead to a cesarean?

No. There’s no evidence that an epidural will slow your labor progress or increase your chance for a cesarean delivery (C-section). It may actually speed up your labor because it relaxes you.

How common are epidural failures, and what causes them to fail?

Sometimes, despite best efforts, an epidural might not work. This means you will still feel pain after it’s placed. Epidurals don’t fail very often. Almost 90% are successful, with a failure rate of a little over 10%. There are several reasons why an epidural might fail:

• The catheter may not be in the right place for the medication to numb you appropriately. 

• Your catheter could move out of place, causing your epidural to stop working.

• The amount of medication given through the catheter may not be enough to numb you completely.

• You may get patchy pain relief — good relief on one side but not the other. This might be due to a combination of placement and dosage. 

• It may be difficult to access the correct area of your back to place the epidural.

Are some people more at risk of an epidural failure?

If you have certain back problems, like scoliosis (abnormal curving of your spine), your provider may not be able to place the epidural at all. If you have had back surgery in the past, this may also affect proper catheter placement. Epidural placement may also be difficult in people with larger body size.

If an epidural fails, can I try another one?

Depending on why your epidural fails, you may have the option of trying again. For example, if the catheter moves out of place, your provider may recommend trying to place it again. Or if you’re only numb on one side and still have pain somewhere else, they may recommend redoing it. But if the initial failure was due to poor access, then trying again might not be an option. 

Are there other options for pain management if the epidural fails?

Yes, there are other methods for pain control during labor.

You can get medication through your IV that can help with the pain. But most IV medications can pass through your blood to the baby and affect their breathing rate. This will limit at what point in labor you may be able to get these IV medications. If given too close to delivery, then the baby may not be able to breathe well on their own after birth.

If you are too close to delivery for IV medication, you may still have the option of local anesthesia. Your provider can give you an injection to numb the nerves in your vaginal canal so you feel less pain during delivery.  

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Written by:

Andrea Kemp, MD, MPH

Dr. Kemp is an accomplished board-certified physician with over 25 years of clinical experience. She completed medical school and residency training in obstetrics and gynecology in Cincinnati, Ohio.

Edited by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined her interests in clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

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