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.

Nevertheless, these trials suggest that epidurals are, at the very least, no worse than other drugs given for comfort. A 2011 analysis of six randomized controlled trials published since 1995 and involving more than 15,000 women concluded that even when given early in labor (before the cervix is 4 centimeters dilated), epidurals do not increase the risk of C-section compared with other pain medications. A similar study published in December 2011 looked at 38 randomized controlled trials and concluded the same thing.

There is one study that did break with convention—and conventional ethics—to compare women who received epidurals with those who received no drugs at all in a randomized and controlled manner. This trial, published in 1999 by researchers in Mexico, gave epidurals to one-half of a group of 129 women who were in labor, while leaving the other half unmedicated. Then the doctors recorded how long it took for their patients to dilate and deliver, what type of delivery they had, and how much pain they said they experienced. The women with epidurals did, in fact, dilate more slowly and take longer to deliver, but they were no more likely to undergo C-sections than women who did not have drugs. And unsurprisingly, 100 percent of the women who had no drugs described their labors as “very painful,” compared with just 9 percent of the women with epidurals. But U.S. researchers know very little about this study other than the details described in its abstract, and it is rarely referenced in literature reviews.

Based on all of this evidence—which, of course, is far from perfect—the American Congress of Obstetricians and Gynecologists published a position statement in 2006 concluding that “the fear of unnecessary cesarean delivery should not influence the method of pain relief that women can choose during labor.”

There are other factors to consider when pondering epidurals, too. Some (but not all) research suggests that they, more than other drugs, increase the risk that a doctor will use forceps or a vacuum extractor to pull the baby out of the birth canal, which can cause bruising and jaundice in the baby as well as vaginal injury. But newer epidurals reduce this risk: In 2001, researchers randomly assigned women requesting epidurals to receive either the “old” 0.25 percent local anesthetic infusion or the new low-dose formulation and found that the women with the newer epidurals were 9 percent less likely to have instrumental deliveries. And since epidurals minimize pain, they keep the mother from hyperventilating, which is thought to improve oxygen availability to the fetus. Epidurals may also have subtle effects on a woman’s physiology, lowering her blood pressure (which can be a benefit or a drawback depending on her blood pressure status in labor) and inducing a mild fever 10 to 15 percent of the time. Finally, epidurals do seem to lengthen the final stages of labor by about 15 minutes.

What about breastfeeding? Natural birthers claim that epidurals impede post-birth breastfeeding because they make babies drowsy. But again, based on the science, it is unclear whether epidurals actually cause breastfeeding problems or are just associated with them. C-sections and other complicated deliveries often require epidurals, and these types of births do impair breastfeeding—but that could be because recoveries from such deliveries are long and painful, not because of direct effects from the epidural. A 2010 study published in the International Journal of Obstetric Anesthesia followed 87 women who had epidurals during labor and reported that 95 percent of them were successfully nursing six weeks after delivery. As for whether epidurals make newborns sleepy: A 2011 study published by nurses at the University of Illinois at Chicago reported that women who received epidurals had similar levels of the stress hormone cortisol in their umbilical cord blood immediately after birth as women who had no drugs. Since cord blood cortisol is a good proxy for newborn alertness, the findings suggest that epidurals probably have no effect.

All in all, then, how dangerous are epidurals? One could make the case that it’s silly to experience such agony on account of putative risks that don’t concern the clinicians who deliver dozens of babies each week. At the same time, these doctors may be biased, and the science on epidurals will never be 100 percent certain. To confuse things further, the issue is growing more polarized. Celebrities including Ricki Lake and Gisele Bündchen have gone public about why they chose natural births; anesthesiologists have published books about why women should embrace epidurals, arguing that they might even be beneficial because they reduce the baby’s exposure to labor-pain-induced stress hormones.

Women shouldn’t cave to pressure from either side. They should make informed decisions based on their goals and priorities. I aspired to have a comfortable birth even if it meant being surrounded by nurses and doctors and tubes and incessant beeps; other women may trade pain for a more intimate birthing experience. Each choice comes with its own benefits and unpleasantries. My unnatural childbirth left me with a memory that does not involve intolerable pain, and that’s exactly what I wanted.

Melinda Wenner Moyer is a science writer based in Cold Spring, New York, and is DoubleX’s parenting advice columnist. Follow her on Twitter.

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