Moms-to-be use less pain medication when they control the dose

There's no doubt about it: epidurals are great at relieving pain during childbirth. But they aren't without drawbacks. They can slow down a woman's labor, for example, and may rapidly decrease her blood pressure, which can affect her baby's heart rate. Also, some women—although grateful for the pain relief— don't much like being numb from the waist down, which can make the pushing stage of labor more difficult.

For these women, an alternative type of epidural called patient-controlled epidural analgesia may be an appealing option, as it allows a woman to control her dose of pain medication. By pushing a button, she can give herself more medicine if she needs it. That way, she can modify her dose in response to her pain and stage of labor. She may decide, for example, that some discomfort is a fair trade-off for not losing as much sensation in her lower body.

Several studies have suggested other benefits as well, including a shorter labor and a drop in how much pain medicine women use. Now, researchers have done a larger, good-quality study to put such benefits to the test. The study hasn't been published yet, but its findings were reported at the annual meeting of the Society for Maternal-Fetal Medicine in San Francisco.

The researchers recruited 270 first-time mothers and randomly assigned them to three groups.

• One group had continuous epidural infusions (CEIs). This is the usual type of epidural. A constant level of pain medicine is infused into the woman's spine through a small tube inserted in her lower back.
• The second group also had CEIs but were able to get an additional dose of medicine every 20 minutes by pushing a button (patient-controlled epidural analgesia, or PCEA for short)
• The third group had PCEA on its own.

Neither the women nor their doctors knew which type of pain relief they were being given, as all the women had buttons to push.

Women in all three groups reported high levels of satisfaction with their pain relief, even though women in the PCEA-only group had more discomfort during the pushing stage.

The researchers didn't find any major differences among the groups in how long the women's labors lasted and their chances of needing an operation to deliver their baby (a caesarean section). However, women in the PCEA-only group were less likely to need a vacuum pump or another instrument to help deliver their baby.

But the biggest difference between the groups related to how much pain medication the women used. Those in the PCEA-only group used 30 percent less pain medicine on average than women in the continuous infusion group, and 45 percent less than women in the combined group. Less pain medication could mean less chance of side effects and a faster recovery from the numbing effects of the drugs.

What you need to know. If you're considering having an epidural, this study suggests you'll be as satisfied with the pain relief provided by the patient-controlled variety as you would be with a standard epidural. A patient-controlled epidural may also provide other advantages, such as more control over your labor, a less medicated delivery, and a lower chance of having an instrument-assisted birth.

—Sophie Ramsey, patient editor, BMJ Group

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