Are Epidurals Really So Bad?

Health and medicine explained.
Jan. 11 2012 3:28 PM

The Truth About Epidurals

Are they really so bad?

Labour - breathing exercises
Does "natural birth" have significant benefits over using an epidural?

© Leah-Anne Thompson

Every pregnant woman who plans a vaginal birth has to contend with the fact that she will have to squeeze a head the size of a grapefruit through her much-smaller-than-a-grapefruit-sized vagina. In other words, that shit is gonna hurt. But if she considers getting an epidural, as 60 to 80 percent of first-time pregnant American women do, there’s a good chance she will hear that this form of pain relief—in which anesthesiologists administer a low-dose anesthetic and narcotic through a catheter into the epidural space surrounding her spinal cord—will degrade the birth experience and potentially harm both mother and baby.

To proponents of natural childbirth, epidurals (and other pain-relieving drugs—epidurals being the most common and effective) contribute to the over-medicalization of motherhood. Such treatments create a snowball effect, they argue, necessitating additional interventions and intrusions: IVs (which sometimes deliver synthetic oxytocin to speed up the labor process), catheters, blood pressure monitors, and electronic fetal monitors.

When I was pregnant last year, I didn’t mind the thought of giving birth in a hospital surrounded by machines. But I did worry about the direct health effects that epidurals might have on my labor and my baby. The popular pregnancy book The Birth Partner, which two friends had independently given me, notes that epidurals make it more difficult for women to push when it comes time to deliver. The nonprofit Childbirth Connection explains on its website that epidurals lengthen labor. Midwifery Today magazine warns that epidurals’ numbing effects on pelvic muscles ultimately increase the risk of cesarean section, a surgery entailing a long recovery, risk for post-op infection or hernia, and future pregnancy complications. And La Leche League International, a nonprofit organization that promotes breastfeeding, warns that epidurals prevent newborns from suckling properly, which could impair nursing success. Counter all this with the reassuring words of obstetricians and anesthesiologists who tout epidurals as being completely safe.

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So what was I to believe?

To find answers, I dug into the dozens of studies that doctors have published on epidurals. What I discovered is that there aren’t many clear answers—epidural research has been fraught with methodological problems—but in sum, the concerns voiced by natural birthers are exaggerated.

Take the claim that epidurals impede a woman’s ability to push. Before the mid-1990s, this was almost certainly true. But back then, epidurals were different. They contained a concentration of 0.25 percent local anesthetic, which blocks the channels on nerve membranes that are necessary for propagating pain signals to the brain. At high enough concentrations, anesthetics can also affect motor neurons, preventing communication between muscles and the brain and making it difficult for women to push. Today, epidurals provide a quarter to half that concentration of local anesthetic, plus a very low dose of narcotics—which have no effect on motor neurons—to take the edge off. In a double-blinded study published in 2001, researchers gave women in early labor a dose of narcotics through an epidural catheter and then split them into two groups, providing half with the current epidural regimen and the other half with no additional pain medication. The women who had the epidurals were equally as able to lift their knees, wiggle their toes, and walk as those who had no additional meds.

Next there is the argument that epidurals increase C-section risk. The studies that have suggested this effect have been observational, reporting that women who choose epidurals are more likely to have C-sections than women who don’t. But the women who requested epidurals in these studies tended to be different from the ones who had natural childbirths: For example, they were more likely to have had painful, difficult labors—on account of carrying large babies or those in abnormal positions, or because their labors were induced. One study reported that women who request the drugs have smaller pelvises than women who do not, a characteristic that makes labor more of an ordeal and independently increases the chance that a doctor will have to operate. So just because epidurals are associated with C-sections does not mean that they cause them. Taking Excedrin is associated with crankiness, but last night’s open bar is your culprit, not your pain reliever.

(In the interest of full disclosure, I had an epidural and an emergency C-section, but I blame my surgery on the fact that I was induced for medical reasons at 39 weeks.)

How can scientists tease out the cause-and-effect here? Ideally, they would split laboring women into two groups at random, giving one epidurals and the other no pain medication, and then watch what happens. But most doctors agree that it would be unethical to withhold medication from laboring women in the name of science.

To get around this dilemma, doctors have designed clinical trials comparing the effects of epidurals with those of IV narcotics. But these studies suffer from a major flaw in that they are comparing epidurals with other medicines that might affect labor. They also aren’t “double-blinded,” because the doctors and patients both know which form of pain relief is being administered—and doctors who believe that epidurals impede labor might be more likely to call for C-sections.