Pain during childbirth: Medications and epidurals

Pain during childbirth: Medications and epidurals
Hospitals use various means of pharmacological pain relief. Learn about the pros and cons of each method.

Hospitals usually have a variety of medications on hand to relieve pain during childbirth. These include narcotic analgesics, nitrous oxide, and epidural analgesia.

Choosing a method of pain relief

Barring medical contraindications, you have the right to choose which available pain relief method to use. It’s important to do your homework so you can make an informed decision. Make sure to consult trustworthy and verifiable sources. If you intend to give birth without medication, our article Non-pharmacological pain relief during childbirth may be of interest to you.

Do you have a birth plan? A birth plan lets you indicate your preferences for labour and delivery.

Your health care provider can tell you about the types of pain relief available at your hospital, as they vary from one facility to the next. Feel free to make whatever decision feels right; most importantly, give yourself the option to change your mind during labour. Remember that you can always speak to your nurse if you have any questions.

Narcotic analgesics

Narcotic analgesics include drugs like morphine, fentanyl, and remifentanil. These medications can be administered by pump. While each has its own particularities, narcotic analgesics are generally of limited use. The more intense the pain, the higher the required dose; however, side effects such as respiratory depression and drowsiness limit how much of the narcotic can be administered, which means the pain is often only partially reduced. In addition, if the mother gives birth while the drug is still active, her baby may also experience temporary drowsiness and decreased muscle tone.

Nitrous oxide (Entonox)

Nitrous oxide is an inhaled gas that offers partial pain relief. It acts quickly and for a very brief period—the mother must breathe it in with each contraction. The main side effects are dizziness and nausea or vomiting. If you feel unwell, simply stop breathing the gas and the effects will disappear.

Epidural analgesia

Epidural analgesia is administered by inserting a small, flexible tube called a catheter into the space around the spinal cord (epidural space) in your lower spine. The catheter is used to inject a solution containing a local anesthetic and a small dose of narcotic.

This solution anesthetizes (“freezes”) the nerves in the abdomen, which, for most women, numbs the pain of labour. It is the most effective way to relieve labour pain.

How is an epidural given?

This medical procedure is performed by an anesthesiologist. A nurse will set up an intravenous solution for you beforehand. The anesthesiologist will start by reviewing your medical records and asking you questions about your health. They will then proceed with the epidural:

  • You can sit upright or lie on your side with your back curved.
  • After applying an antiseptic to your back, the anesthesiologist injects a local anesthetic to numb the area.
  • A needle is inserted into the epidural space.
  • A catheter is passed through the needle, which is then removed, leaving only the catheter in place until delivery.

A patient-controlled device may be attached to the epidural catheter, allowing you to administer the medication yourself. It takes about 30 minutes on average from the start of the procedure to achieve optimal pain relief.

When can I request an epidural?

If labour contractions become too painful, most women can request an epidural at any time, provided the anesthesiologist is available. The cervix does not need to be dilated to a certain size. However, if the baby is about to be born, a faster method of pain relief will be considered.

A very small number of women are strongly recommended to receive an epidural in the early stages of labour due to a particular medical condition. If you’re in this situation, your health care provider will arrange for you to see an anesthesiologist.

Conversely, there are also medical conditions that contraindicate epidural analgesia. These tend to be coagulation abnormalities, serious infections, and rare illnesses. In this case, the anesthesiologist will meet with you to determine whether an epidural is really contraindicated and to evaluate other pain relief options.

What are the possible side effects of an epidural?

  • Heavy legs and difficulty urinating
    Most of the time, an epidural freezes not only the nerves in your stomach, but also those in your legs and bladder. As a result, your legs may feel numb and heavy. This is why women should usually stay in bed after receiving an epidural. If you’re unable to urinate, your nurse may temporarily insert a small tube into your bladder to allow urine to pass (urinary catheterization).
  • Itching
    This side effect can be relieved by modifying your epidural infusion.
  • Decreased blood pressure
    As your blood pressure may drop, it will be checked regularly in the minutes following your epidural.

What are the risks of an epidural for the mother?

  • Partial or no pain relief
    In a small number of patients, the epidural may have no effect or only partially relieve the pain. The anesthesiologist may try to optimize the epidural or, in some cases, redo it. However, when an epidural fails to provide pain relief, it isn’t always possible to determine the cause.
  • Headache
    Epidurals can also lead to headaches following delivery, a condition known as postdural puncture headache. This can occur if the epidural needle accidentally pierces a membrane called the dura mater, causing a headache that characteristically grows worse when you stand and is least painful when you lie down. If you seem to be experiencing this symptom in the days after giving birth, you should speak to your health care provider.
  • Infection
    Any procedure that involves piercing the skin and inserting a foreign object (e.g., a catheter) can cause an infection. To prevent this from happening, the anesthesiologist who performs your epidural will be wearing sterile gloves, a cap, and a mask. Your skin will also be disinfected before the injection to further minimize the risk.
  • Breathing problems
    In very rare cases, an epidural can cause difficulty breathing due to the anesthetic effect extending too high. This usually indicates that the catheter isn’t properly positioned. When this occurs, the procedure is stopped until the breathing issues subside.
  • Numbness or weakness in the legs
    Many women are afraid of becoming paralyzed after an epidural. A very small percentage of women experience numbness or weakness in one leg for a few weeks after giving birth. The symptoms usually go away with time. Leg numbness or weakness can result from poor positioning during labour or a difficult delivery. An epidural reduces the amount of feeling in your legs, making it more likely you’ll adopt positions that compress your leg nerves during labour. That’s why it’s important to follow your nurse’s advice during labour. For example, they might suggest that you change positions every 30 minutes.

    True paralysis with long-term consequences is extremely rare. In medical research, there are very few reports of women becoming paralyzed following an epidural during childbirth. The women in these cases had coagulation problems. For this reason, epidurals are contraindicated in patients with coagulation abnormalities.

What are the disadvantages of an epidural for the baby?

  • Following an epidural, the baby’s heart rate can sometimes slow down for a few minutes. It typically returns to normal with no complications.
  • Epidurals are also associated with a slightly higher use of forceps or vacuum extraction.
  • The second stage (pushing) also lasts slightly longer because some women have more difficulty pushing effectively while under epidural analgesia.

What an epidural does not do

  • An epidural does not increase the risk of having a caesarean section.
  • An epidural does not cause back pain.
  • An epidural does not make the baby groggy or sleepy. The actual amount of medication transmitted to the baby is very small.
  • An epidural does not interfere with breastfeeding.


Things to keep in mind

  • There are many pharmaceutical methods of pain relief.
  • Your health care provider can tell you about the methods available at your hospital.
  • Barring medical contraindications, you have the right to choose which available pain relief method to use.


Naître et grandir

Scientific review: Dr. Sandra Lesage, anesthesiologist, CHU Sainte-Justine
Copywriting: The Naître et grandir team
Updated: October 2020


Photo: iStock/RapidEye



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  • Demers, Stéphanie, and Sandra Lesage. “L’analgésie en salle d’accouchement : dix mythes et réalités.” Le Médecin du Québec, vol. 52, no. 7, July 2017.
  • Hawkins, Joy L. “Epidural Analgesia for Labor and Delivery.” New England Journal of Medicine, vol. 362, 2010, pp. 1,503–1,510.