Friedman’s Curve and Failure to Progress: A Leading Cause of Unplanned C-sections
In 2013, researchers published a report of 38,484 first-time C-sections that occurred among a national sample of women. The overall C-section rate among first-time mothers was 30.8%. More than 1 in 3 (35%) of these Cesareans were due to a diagnosis of “failure to progress,” or slow progress in labor. This means that 10%, or 1 in 10, of all first-time mothers in the U.S. had a Cesarean for failure to progress during the years 2002-2008 (Boyle, Reddy et al. 2013).
More than 4 in 10 of these women who had C-sections for failure to progress had not even reached 5 cm dilation before they were taken to surgery. This means that many of these women were still in very early labor when they were told that they weren’t dilating fast enough (Boyle, Reddy et al. 2013).
Out of women who reach the pushing phase, 1 out of 3 of cesarean deliveries for failure to progress during pushing were performed at less than 3 hours of pushing in first-time mothers, while 1 out of 4 C-sections for failure to progress during pushing were performed at less than 2 hours in experienced mothers. This is of concern because the 2003 ACOG guidelines define “arrest of descent” as greater than 3 hours in first-time mothers with epidurals and greater than 2 hours in experienced mothers with epidurals, and the majority of American women have epidurals during labor– which can lead to a slower pushing phase (Zhang et al. 2010b).
So what’s the bottom line?
The definition of a “normal” length of labor that is currently used by most healthcare providers is obsolete. The new, evidence-based definitions of normal labor, labor arrest, and failed induction should be adopted immediately. As long as mother and baby are both healthy, and as long as the length of labor does not qualify as an arrested labor, laboring women should be treated as if they are progressing normally. Women who are being medically induced should be given more time to complete the early phase of labor. Importantly, six centimeters should be considered the start of the active phase—not four centimeters—and caregivers should keep in mind that normal early labor (before 6 cm) sometimes includes a period in which there is no change in dilation for hours.
In the end, if more care providers begin using evidence-based definitions of labor arrest and failed induction, we will begin to see fewer of these diagnoses, and a simultaneous lowering of the Cesarean rate.