Many expecting mothers wonder if getting an epidural during labor will prolong the birthing process. An epidural is a form of pain relief that blocks sensation in the lower part of the body. While epidurals are very effective at reducing pain, some studies suggest they could potentially lengthen the second stage of labor. However, the overall impact on total labor duration is small and other factors play a larger role.
What is an Epidural?
An epidural is a procedure where anesthesia is injected into the epidural space surrounding the spinal cord. This numbs the nerves that transmit pain signals from the uterus and birth canal. Epidurals contain low doses of local anesthetics like bupivacaine combined with opioids like fentanyl. The medications diffuse into the spinal fluid and nerves, blocking pain sensation.
The amount of numbness depends on the drug dosage, with higher doses providing more complete pain relief. Lower dose “walking” epidurals allow some mobility while still easing pain. Epidurals can be given at any point during labor and provide effective pain relief within 10-20 minutes. The pain relief lasts 1-2 hours, after which the epidural can be topped up to maintain the effect.
Does Epidural Use Lengthen Labor Stages?
Labor is divided into three stages:
Stage 1: Early, Active Labor
Stage 1 involves the early contractions that cause the cervix to thin out (efface) and open up (dilate). This stage ends when the cervix is fully dilated at 10 cm.
Most studies show epidurals do not significantly prolong the first stage of labor. A major review covering over 15,000 women found that epidurals only increased first stage labor by 42 minutes on average compared to unmedicated births. Other analyses have found even smaller differences of 14-20 minutes.
This minor impact is likely because an epidural does not remove contractions needed for cervical dilation. It only blocks the pain of the contractions. Early epidural use also limits release of labor-slowing stress hormones like epinephrine.
Stage 2: Pushing and Birth
Stage 2 starts when the cervix is fully dilated and ends with the birth of the baby. This part involves “pushing” – using abdominal muscle contractions to expel the baby.
Some evidence suggests epidurals may somewhat prolong the second stage of labor. However, the effect size varies between studies:
| Study | Increase in Stage 2 Length with Epidural |
| Camann et al. (2020) | No significant difference |
| Wassen et al. (2011) | 8 minutes longer |
| Anim-Somuah et al. (2018) | 15 minutes longer |
| Alexander et al. (2002) | 26 minutes longer |
The average appears to be around 15 minutes longer for stage 2 in epidural recipients. However, some analyses find no difference.
There are a few reasons an epidural may prolong pushing:
– It relaxes the pelvic muscles, possibly hampering rotation of the baby through the birth canal.
– Numbness in the lower body reduces the mother’s ability to effectively push.
– It makes it harder for the mother to move into optimal birthing positions or use techniques like squatting.
However, any elongation of the second stage with epidurals is relatively small. Other factors likely play a bigger role in determining this labor stage’s duration. For example, first-time mothers have an average second stage of 54 minutes versus 18 minutes in moms who have given birth before. The baby’s size and position can also significantly impact the length of pushing.
Stage 3: Delivery of the Placenta
The third stage starts after birth and ends once the placenta detaches from the uterine wall and is expelled. Studies show epidurals do not appear to prolong the third stage of labor at all compared to unmedicated birth.
Does Epidural Use Increase Total Labor Duration?
The most important question for mothers is whether getting an epidural will significantly lengthen their total time in labor.
Based on the current evidence, any increase in total labor duration associated with epidural use is likely 30 minutes or less on average:
| Study | Average Total Increase in Labor Length with Epidural |
| Sharma et al. (2016) | No significant difference |
| Sng et al. (2018) | 17 minutes longer |
| Segal et al. (2012) | 26 minutes longer |
| Halpern et al. (2004) | 27 minutes longer |
While reaching 30 minutes longer may seem concerning, total labor duration has high natural variability between women. It ranges from 3 hours to more than 20 hours among healthy first-time mothers. The minor increase associated with epidurals is relatively small in context of this wide range.
Other maternal health factors like age, weight, pregnancy history and cervical ripeness have a more substantial impact on labor duration. Induction methods and use of oxytocin also lengthen labor more significantly than epidurals.
Do Epidurals Increase the Risk of C-Section?
Some mothers worry that epidurals could raise the risk for cesarean delivery. However, studies consistently show epidurals have no effect on a woman’s chance of C-section when controlled for other factors.
In a major review, epidurals increased the C-section risk by only 0.4% compared to unmedicated birth when adjusted for pregnancy and delivery variables. Other large studies found no difference in cesarean rates with epidural usage.
The minor second stage labor prolongation seen with epidurals does not appear to impair vaginal delivery. For the majority of women, labor still remains within the normal range needed for spontaneous vaginal birth.
Do Lower Dose “Mobile” Epidurals Have Less Impact?
In recent years, lower dose “walking” epidurals have become more popular. These lighter epidurals use lower medication amounts, allowing more mobility during labor.
A few studies suggest walking epidurals may have less impact on labor duration compared to traditional epidurals:
– Capogna et al. found no difference in first or second stage labor length with low dose epidurals.
– Comparisons by Wang et al. and Halpern et al. found walking epidurals increased labor by 8-14 minutes versus 27-28 minutes with regular epidurals.
The ability to change positions and walk around provided by lighter epidurals may facilitate labor progress and descent of the baby. However, more research is needed to clarify if low dose epidurals conclusively mitigate labor prolongation.
Other Potential Effects on Labor
While minimal, epidurals may have other small impacts on the birthing process:
– They may slightly increase use of oxytocin and other labor augmentations. This is likely due to the slight first stage prolongation.
– Instrumental vaginal delivery rates may be higher with epidurals, possibly due to poorer pushing. However, effect sizes are inconsistent between studies.
– Epidurals provide very effective pain relief but may reduce satisfaction from the subjective “childbirth experience” for some women.
However, these effects are minor and do not strongly deter from the overall safety profile and labor outcomes with epidural usage.
Conclusion
Overall, research suggests epidurals may modestly prolong the second stage of labor by about 15 minutes on average. However, they have little impact on first stage or total labor duration. While epidurals can provide profound pain relief, their impact on the actual birthing process appears relatively minimal. Factors like the baby’s size and position as well as the mother’s parity play a larger role. When considering an epidural, mothers can be reassured any effects on labor are likely to be small. While each woman’s preferences and values differ, epidurals remain an effective option for pain management in most cases.