In the United States, failure to progress is the top reason for unplanned primary cesarean (first c-s delivery).
Failure to progress is a subjective diagnosis, pronounced when a healthcare provider thinks labor is taking longer than it should. It really depends on what the care provider views as normal and abnormal. The couple may or may not feel they have reached their limit of laboring. Sometimes people can feel like it was really a failure to wait, whereas sometimes, it feels like truly something was abnormal. It’s hard to know exactly when something in a labor is normal, or abnormal, plus there are different definitions around the world.
The American Family Physician Journal said that abnormally slow or protracted labor accounts for about 25 to 55% of all cesarean deliveries. This is our best guess in the US. In the UK, it’s the cause of about 34% of cesareans. So about one in three C-sections is due to failure to progress. In Australia, it’s around 42% of cesareans.
HISTORY:
Dr. Emanuel Friedman published a study in 1955 that became the basis for this diagnosis (though he did not intend it to become a “guideline” but rather an observational report). In his most famous study, of first time mothers, he followed the labors of 500 white women giving birth at Sloan Memorial Hospital in New York City. Others had measured the total length of labor, but what Friedman did was to and routinely and repeatedly measure the cervix of everyone in labor so that he could graph how quickly they were dilating.
He plotted their labors on a curve, literally, hand drew a curve in this article, called a partograph, which in the U.S. came to be called Friedman’s Curve. What did Dr. Friedman find? The average length of time it took to get from zero to four centimeters was 8.6 hours.
Once the patients in his study reached 4 centimeters, labor sped up, and they actually dilated on average 3 centimeters per hour. It took around 4.9 hours to get from 4 to 10 centimeters. There was a little bit of a slowing down between 9 and 10. The average length of pushing after 10 centimeters dilation was one hour. This is the study that kind of solidified the definition of active labor as starting at 4 centimeters; once you reach four centimeters, you speed up and you’re considered to be an active labor.
A few things to note. There were 500 women in the study, all-white (segregation was in effect in 1955), at one hospital. Virtually, all of these women were given morphine and scopolamine, and a large percentage of these patients were heavily sedated. (They were not given epidurals, which did not exist at the time.) Our population is older, and heavier, and we have way more use for epidurals.
It is possible that the heavy levels of sedation made labor go quickly because if you remove or reduce anxiety, without paralyzing the pelvic floor muscles (as with epidurals), it can actually help relax the pelvis and improve dilation.
There are huge differences between people giving birth now as compared to the 1950s. In the early 2010s, there was a public health push to lower the cesarean rate, which reached around 33%. The number one reason that unplanned primary or first cesareans were happening was because of failure to progress, so there was a need to revisit that. There was a big study of over 62,000 people that gave birth across 19 different hospitals in the United States. One of the big things that was noted was that unlike what Friedman had cited with labor speeding up around 4 centimeters, more modern labor curves showed that labor was speeding up for most women around 6 centimeters. This was seen in women giving birth for the first time as well as those who had given birth before. Another thing that was important was that before six centimeters, there was this latent period that researchers observed in some people, and so their labor could be slow or they could stall out, not progress at all. There was a push to change the definition of active labor from 4 centimeters to 6 centimeters.
While Friedman’s study showed an average of 3 cm per hour, the 2010 study showed that the dilation from 3 to 4 cm could take up to 7 hours. All babies were born normal and healthy, via vaginal births. Since this group was having these longer labors, giving birth vaginally and to healthy babies, we had to redefine normal and recognize that active labor didn’t start as early as we thought it did. We had to acknowledge that it is okay not to have a lot of progress or to stall out when still in early labor.
So in 2014, the American College of Obstetricians and Gynecologists, along with the Society for Maternal-Fetal Medicine, published this new labor guideline and the goal was safe prevention of the primary cesarean.
Research since that 2014 ACOG guideline came out looked at whether or not that guideline is being followed.
One study in 2018, a review of unplanned cesareans that happened because of a failure to progress or arrest of dilation diagnosis at a single academic medical center, saw that of the cesareans that occurred because of this diagnosis, over half of them did not meet the new guidelines. They also saw that care providers were less likely to follow the new guideline if they were attending a birth on a weekend versus a weekday. They also saw that in the cesarean births where the new definitions were not used, there was no decrease in adverse outcomes for the birthing person or the baby. In other words, there was no major safety issue or negative impact, on the birthing person or the baby, when women labored with the new guidelines that allow for longer labors.
So, the new guidelines are slowly making their way into the mindset of hospital providers, and birth care is still affected (as are most things in life) by the personal lives and belief systems of the professionals in whom we place our care. Any major life undertaking usually requires forethought and research. Every woman can become informed about the evidence, history, context, and physiology of birth practices. Childbirth classes are essential to positive birth outcomes.