How often it happens

This is not a rare complaint, and the Obstetric Anaesthetists' Association does not treat it as one. Its published figures, out of every 100 people who had an epidural during labour: "About 10 needed additional pain relief, as well as the epidural — 90 did not. About 5 had to have the epidural re-sited — 95 did not."

The OAA also states the timings people are rarely told: an epidural "takes about 20 minutes to set up and up to 30 minutes before you feel the full effect". A good deal of the distress about an epidural "not working" belongs to those first thirty minutes.

Why it might not take at all

The OAA gives four explanations, and only one of them is about the anaesthetist getting it wrong.

The first is spread. A soft tube sits in your back and medicine is given through it. "Sometimes, even if it's done properly, the medicine doesn't spread well in the space around the nerves." The response is to adjust the tube or give more medicine, and if that does not help, to replace the tube.

The second is timing. "If your baby is nearly ready to be born when the epidural is given, there might not be enough time for the medicine to work fully."

The third is a partial block by region. An epidural can take away abdominal pain and do much less for back or vaginal pain. The OAA asks you to say so, because "more medicine or changes in position might help".

The fourth is not a failure at all. Late in labour you may feel strong pressure in your bottom or vagina, which the OAA describes as feeling "like needing to poo". Even a working epidural can struggle to remove that pressure entirely.

Why one side only

The OAA's explanation is mechanical: "The tube in your back might have ended up more on one side than the other. This means the medicine can go to one side more than the other."

What can be done: more medicine, adjusting the tube, or re-siting it. The OAA also makes a point worth holding onto — "even if one side stays more numb than the other, it may still give enough pain relief". A one-sided block is not automatically a block that has to be redone. That is your judgement to make, not something to be decided for you.

If it happened in a previous labour, tell the anaesthetist next time so they can plan ahead.

Why it worked and then stopped

Three reasons, from the OAA. The tube may have moved or fallen out, "though this is rare", and the epidural can be redone. Labour may simply have become stronger — "it's common to need extra medicine later on". Or the baby has moved down into the vagina, involving new nerves that may need extra medicine.

Back pain in labour, particularly with a baby in certain positions, is singled out as hard to treat with an epidural. The OAA does not pretend otherwise, but asks you to say so anyway.

The four things that can be tried

The OAA lists them in order, and they are worth knowing so you can ask for the next one rather than waiting:

Give more anaesthetic through the tube.
Ask you to change position.
Move the catheter to a different place in your back — re-siting it.
Suggest a different type of anaesthetic altogether.

The NHS lists the ordinary side effects that can accompany all of this, including low blood pressure, temporary loss of bladder control, itchy skin, feeling sick and headache, so that a change after a top-up is not a surprise.

Asking, and being heard

NICE writes two short recommendations into intrapartum care that matter here. "Encourage the woman to say if she needs more analgesia at any point during labour." And earlier: give "ongoing consideration to the woman's emotional and psychological needs, including her desire for pain relief".

Birthrights sets out the legal frame around requesting: "if you ask for pain relief or for your pain relief to be topped up, it should be given unless there are good reasons against providing it. If there is a medical reason for refusing pain relief ... then your doctor or midwife should explain this to you and document the discussion." It adds that healthcare professionals "must not refuse you pain relief or other support simply because of a hospital guideline or policy".

The HSE adds two things worth knowing before the day. Ask during pregnancy what your unit can offer, because midwives "can tell you if your maternity unit, hospital or home birth midwife can accommodate your choice". And expect the plan to move: "during labour you may need less or more pain relief than you had planned."

Afterwards

If an epidural did not work and it has stayed with you, the OAA runs its answers under the heading "birth afterthoughts", which is the same language many maternity units use for their birth reflections services. Its position on the next pregnancy is reassuring and specific: "Just because the epidural didn't work well last time doesn't mean it won't work next time. You can ask to meet with an anaesthetist before your next labour."

That appointment is a reasonable thing to ask for at any point in a subsequent pregnancy, and it is the single most useful thing you can do with a bad experience of one.

What it is not

An epidural that gives incomplete relief is not evidence that you have a high pain threshold, an unusual spine, or a mind that is somehow resisting it. The OAA's explanations are all physical: where the tube ended up, how far labour had progressed, which nerves were involved by the time it was placed.

It is also not a reason to be told to wait and see how you get on. The recognised responses exist precisely because incomplete blocks are expected, and asking for the next one is a normal part of using an epidural rather than a complaint about your care.

Epidural Not Working