A new study, Effect of Immediate vs Delayed Pushing on Rates of Spontaneous Vaginal Delivery Among Nulliparous Women Receiving Neuraxial Analgesia: A Randomized Clinical Trial was released today in the Journal of the American Medical Association and appears to conclude that there is no difference in cesarean rates or spontaneous delivery between laboring people with an epidural who delayed pushing after full dilation versus those who began to immediately push once the cervix was completely dilated.

This topic was most recently covered in Science & Sensibility in 2017, Laboring Down: Is It a Good Idea? - Henci Goer Provides a Research Update, where, after examining the research Henci concluded that:

"For women with epidurals, waiting to push until either a strong urge develops or the head descends to the perineum appears to do little or no harm and is likely to do some good."

Today's published study hypothesized that "the rate of spontaneous vaginal delivery would increase among nulliparous women with immediate pushing compared with delayed pushing." The researchers ultimately concluded that for laboring people with epidurals, "the timing of second stage pushing efforts did not affect the rate of spontaneous vaginal delivery." Let's take a closer look.

How the study was done

People pregnant and full term (37 weeks or beyond) with their first baby who were admitted either in spontaneous labor or for an induction and had a baby with reassuring heart tones and who also received an epidural were eligible to be included in the study. 2414 people participated in the study. Once the laboring person reached 10 cm of dilation, they were randomized to either begin pushing immediately or to "labor down" for 60 minutes prior to beginning pushing effort.  Laboring down is the process of allowing the uterus to continue to contract without maternal pushing effort even though full dilation has been attained.  This is often much easier with a patient with an epidural, as unmedicated people most often develop the urge to push once fully dilated and are unable to resist bearing. The researchers noted that there were no specific differences in maternal or pregnancy-related characteristics between the two groups. The mean time from complete cervical dilation to pushing was 18.9 minutes for those assigned to the immediate pushing group vs 59.8 minutes for those assigned to the delayed pushing group.

The results

The patients assigned to the immediate pushing group had a spontaneous delivery rate of 85.9 and the delayed pushing group rate was 86.5. When examing secondary outcomes, it was found that the immediate pushing group had a shorter duration of second stage of labor (102.4 minutes) versus 134.2 minutes in the delayed pushing group. The immediate pushing group had a longer duration of active pushing, 83.7 minutes, versus 74.5 minutes for the delayed pushing group. The rates of delivery with forceps or vacuum were low and showed no significance between the groups and the need for cesarean section also showed no significant difference.

The rate of postpartum hemorrhage was significantly lower for the people in the immediate pushing group (2.3%) compared to those in the delayed pushing group (4.0%).  Also, it was noted that the rates of chorioamnionitis during the second stage of labor were significantly lower among those assigned to the immediate pushing group (6.7%) compared with the delayed pushing group (9.1%).  There was no significant difference in neonatal morbidity rates or perineal laceration rates. The babies in the immediate pushing group showed a decreased risk of neonatal acidemia (0.8%) compared to the delayed pushing group (1.2%). There was a higher rate of suspected sepsis in the delayed pushing group, 4.4% vs 3.2%) but a lower rate of third-degree perineal laceration. (4.4% 3 vs 5.3%). Neither group of patients indicated more satisfaction over the experience than the other group. There were also no notable differences in amount of blood loss or in the number of babies admitted to the NICU.

Discussion and Conclusion

The researchers state that immediate pushing after reaching complete dilation should be suggested in laboring people with an epidural as there is no difference in spontaneous vaginal delivery rates but the evidence suggests a decrease in maternal and neonatal complications with immediate pushing over delaying active pushing at full dilation. The researchers suggest that immediate pushing with an epidural mimics the behavior of unmedicated laboring people who reflexively push immediately.  Researchers stated that findings in this study showed delaying pushing resulted in a longer second stage and published observational research suggests that

"every additional hour spent during the second stage of labor compared with the first hour, regardless of an immediate pushing vs delayed pushing management strategy, is associated with an increase in maternal and neonatal morbidity. Specifically, a longer second stage of labor has been associated with an increase in the risks of maternal hemorrhage, infection, severe perineal laceration, as well as neonatal acidemia and neonatal intensive care unit admission. Thus, the current finding that delayed pushing prolonged the second stage of labor without increasing spontaneous vaginal delivery rates further argues against routine use of delayed pushing."

Things to consider and questions raised

Of course, I immediately thought of Lamaze International's Fifth Healthy Birth Practice: Avoid Giving Birth on Your Back and Follow Your Body's Urge to Push.  Nowadays, as I support people in my birth doula work who are birthing with an epidural, I notice that more often than not, they do develop an urge to push as the baby descends through the pelvis after complete dilation. The epidural removes the pain but the pressure is still there. Unmedicated people push when they feel the urge, most often, but not always, after dilating completely.  In this study, I wonder if the delayed pushing group felt the urge to push or began pushing after a one hour delay regardless?

The study did not indicate what positions pushing or birth occurred in, or if it was in the "standard" lithotomy pushing, on the back.  Today's epidurals, at least in my community, provide enough mobility to allow for pushing on hands and knees or in a squat.  These position changes may require a bit more support from the birth team, but people pushing with an epidural can rotate through several positions that support fetal descent and rotation. I question if study participants moved through different positions during the pushing phase.

I was surprised that there was no difference in fetal distress between the groups.  It has always been my understanding that pushing is a time where babies may demonstrate some additional stress as they are moved down and out, but the researchers stated this was not observed.

Does this study raise any questions for you, based on your knowledge and experiences?  Will this change how you discuss pushing with an epidural in your childbirth classes?  Let me know in the comments below.

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