Effects of Epidurals on the Second Stage of Labor
- How epidurals could potentially slow the pushing phase of labor
- What randomized, controlled trials and large observational studies have found about the effects of epidurals on the second stage of labor
- If turning off a mother’s low-dose epidural at the start of the second stage makes a difference in labor duration or other health outcomes
- American College of Obstetricians and Gynecologists (ACOG), Society for Maternal-Fetal Medicine (SMFM), Caughey, A. B., et al. (2014). “Safe prevention of the primary cesarean delivery.” Am J Obstet Gynecol 210:179- 193.
- Anim-Somuah, M., Smyth, R. M. and Jones, L. (2011). “Epidural versus non-epidural or no analgesia in labour.” Cochrane Database Syst Rev (12): CD000331.
- Cheng, Y. W., Shaffer, B. L., Nicholson, J. M., et al. (2014). Second stage of labor and epidural use: a larger effect than previously suggested. Obstet Gynecol;123:527–35.
- Shen, X., Li, Y., Xu, S., et al. (2017). Epidural Analgesia During the Second Stage of Labor: A Randomized Controlled Trial. Obstet Gynecol.
- Zhang, J., Landy, H. L., Branch, D. W., et al. and the Consortium on Safe Labor (2010). “Contemporary patterns of spontaneous labor with normal neonatal outcomes.” Obstet Gynecol 116(6): 1281-1287.
View the transcript
Hi everyone, my name’s Rebecca Dekker and I’m a nurse with my PhD and the founder of Evidence Based Birth®.
In this video we’re going to talk about the effects of epidurals on the second stage of labor. In past videos we talked about the benefits and risks of epidurals and we also talked about potential effects of high dose epidurals on breastfeeding. In this video we’re going to focus in on the potential effects of epidurals on the second stage of labor.
The second stage of labor begins when the cervix is fully dilated, includes the pushing phase, and ends when the baby is born. This is an important topic about the length of the second stage of labor because longer second stages have been linked with worse health outcomes for the mother, including a higher risk of infection, a higher risk of having a severe tear, a higher risk of post partum hemorrhage, and a higher risk of needing forceps/vacuum or Cesarean.
Concerns About the Effects of Epidurals on the Second Stage of Labor
Researches have suggested that epidurals could potentially decrease the mothers pushing efforts by reducing the effectiveness of the uterine contractions during the pushing phase. And possibly, they might relax the pelvic floor, which would affect the baby as it is rotating and coming out.
What Have Studies Found About the Effects of Epidurals on the Second Stage of Labor?
A large body of research evidence has shown that epidurals are linked to a longer second stage of labor. This has been demonstrated in large observational studies as well as in randomized control trials.
One large study was led by Zhang and was published in 2010. These researchers looked at more than 62,000 people that gave birth across the United States. About 80% of the people in the study had an epidural. They found that the average length of the second stage of labor was one-hour-and-six-minutes for first time mothers with an epidural and 36-minutes for first-time mothers without an epidural.
People who had given birth before, and this was a subsequent vaginal birth, had faster second stages than the first time moms. If you’d given birth vaginally before and you were in this study, you spent an average of about 30-minutes pushing with epidural and 15-minutes pushing if you did not have an epidural.
Another study looked at 42,000 people giving birth in California. When they looked at first-time mothers who were giving birth with an epidural, about half of them gave birth within two hours, and the other half took longer. When they looked at first-time mothers giving birth without an epidural, about half of them had given birth within 47-minutes, and the other half took longer. In other words, epidural use added about 73-minutes to the second stage of labor for these first-time moms.
We can also look at the Cochrane review of more than 38 randomized control trials that had nearly 10,000 participants total. They found that second stages of labor were, on average, about 14-minutes longer with an epidural.
Did the Recent Study by Shen et al. (2017) Find That Epidurals Do Not Lengthen the Second Stage of Labor?
Recently there’s been a lot of news headlines about a new study that came out claiming that epidurals do not lengthen the second stage of labor. I had a lot of people reach out to me with questions about that study and concerns. What does this mean? For example, an article in the Huffington Post had the headline that said “Epidurals Don’t Necessarily Slow Labor, Study Finds.” Well, the study that they were talking about took place in China in the year 2015, and was published in 2017 in the Journal of Obstetrics and Gynecology. People in the study were first-time mothers giving birth at term to a single baby. They all went into labor spontaneously and they all requested epidurals.
Everyone received a very low-dose of medication in their epidurals, so these are considered what we call low-dose epidurals. At the start of the pushing phase of labor, they’d already been receiving the epidural all the way through the first part of labor. At the start of the second stage 178 mothers were randomly assigned to receive saline or salt water placebo through their epidural. And 171 mothers were randomly assigned to continue receiving the low-dose epidural solution with epidural medications. Both the patients and the care providers were blinded, so they didn’t know what type of solution the mothers were receiving.
What Did They Really Find?
They found that the length of the pushing phase was similar in both groups. It was about, on average, 51 to 52 minutes of pushing. Also, rates of vaginal birth were similar between the two groups, about 97 to 99%.
It’s also interesting to note that the pain scores were similar between the two groups. What this means is that both groups were still being effected by the epidural medications they’d received during the first stage of labor. Ropivacaine is the drug that they had been receiving all throughout the first stage. This is a long acting drug that lasts about, on average, four hours in your body. Even though they had turned the epidural off for half of the people in the study, the medications were still in their system. This particular study was not comparing epidural versus no epidural, it was looking at the effects of turning off the epidural at the start of the second stage. And basically, they found that because the medications remain in the mothers body, turning off the epidural at the start of the second stage probably doesn’t have any effect on the length of the second stage.
It’s Important to Be a Critical Reader
I want to encourage you to be weary of news headlines that say things like “New Study Proves.” It’s important to consider the overall body of evidence. What has all the research shown up until this point? Also, if you can, it’s important to find the study for yourself and look at it or ask somebody else to look at it with you, like a trusted healthcare provider. You need to look at the methods of how they actually carried out the study, including the limitations of the study. A lot of people are tricked by these headlines. They thought this one meant that epidurals don’t lengthen the second stage. And that’s not what the study was looking at at all, so it’s not what they found.
I hope this was helpful for you, and hopefully it was a good lesson in making sure you look at the details of the studies before you take their summaries to heart. That’s it for this video, thanks and bye. To learn more and subscribe to our newsletters for useful information, please visit evidencebasedbith.com.
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