This week's blog post explores the concept of "failure to progress" during labor and is based on a recent article at Evidence Based Birth. Please visit their website for more details and a full list of references.
C-Sections and Friedman's Curve
As most supporters of Lamaze childbirth preparation know, the C-section rate in the United States is among the highest in the world. About 30% of first time moms end up having C-sections, and about 35% of those C-sections were performed due to a diagnosis of "failure to progress."
Recent research, however, has shown that the standard measure of labor progress--Friedman's Curve--is outdated, and that following this standard may result in unnecessary interventions, including C-sections. Friedman's Curve, published in 1955, describes the average length of time it took for women in Friedman's study to dilate each centimeter. Friedman found that the average time to get from 0-4cm dilation was 8.6 hours, the average length of time to get from 4-10 cm was 4.9 hours, and the average length of "pushing" was 1 hour. Friedman's data showed that labor sped up once women entered the active labor phase (about 4 cm) until they reached about 9cm dilation.Until recently, women whose labors did not follow Friedman's standards often had their labors induced or augmented (generally by use of pitocin).
Changes in Labor Since 1955
Although based on data from 500 first time mothers, labor conditions in 1955 were much different than today. In 1955 most women were moderately to heavily sedated during labor (Twilight Sleep was still common). Maternal demographics have changed greatly over the years as well, so today's moms are more likely to be older, overweight, etc .
In order to see whether Friedman's curve was still useful, a 2010 research study examined labor records from more than 62,000 women across the US. This study found that for women who go into labor on their own, labors tend to be much slower than in 1955. Most women do not start dilating rapidly at 3cm as Friedman had found, and many women went for long periods of time without any dilation. In and of themselves, today's longer labors have not been shown to generate increased risk of harm to baby or mother. However, if labor progress is measured by old standards, today's women are more at risk for medical interventions aimed at speeding up labor.
New Standards
In 2013 the definitions of normal labor and arrested labor were updated to reflect recent research. It is recognized that active labor may not begin until 6cm dilation, and the new definitions make it more difficult to diagnose arrested labor. It is hoped that these new definitions will decrease the rate of preventable C-sections.
The new standards make it more likely that families will be able to follow the Healthy Birth Practices promoted by Lamaze International, in particular Healthy Birth Practice 1: Let Labor Begin On Its Own and Healthy Birth Practice 4: Avoid Interventions that Are Not Medically Necessary.
Most importantly, the new standards do a better job of recognizing that every woman is different, and that labor does not progress in the same way or at the same speed for everyone. Women's bodies are uniquely designed to undergo the process of pregnancy and labor, and in most cases can get the job done well without much intervention.
C-Sections and Friedman's Curve
As most supporters of Lamaze childbirth preparation know, the C-section rate in the United States is among the highest in the world. About 30% of first time moms end up having C-sections, and about 35% of those C-sections were performed due to a diagnosis of "failure to progress."
Recent research, however, has shown that the standard measure of labor progress--Friedman's Curve--is outdated, and that following this standard may result in unnecessary interventions, including C-sections. Friedman's Curve, published in 1955, describes the average length of time it took for women in Friedman's study to dilate each centimeter. Friedman found that the average time to get from 0-4cm dilation was 8.6 hours, the average length of time to get from 4-10 cm was 4.9 hours, and the average length of "pushing" was 1 hour. Friedman's data showed that labor sped up once women entered the active labor phase (about 4 cm) until they reached about 9cm dilation.Until recently, women whose labors did not follow Friedman's standards often had their labors induced or augmented (generally by use of pitocin).
Changes in Labor Since 1955
Although based on data from 500 first time mothers, labor conditions in 1955 were much different than today. In 1955 most women were moderately to heavily sedated during labor (Twilight Sleep was still common). Maternal demographics have changed greatly over the years as well, so today's moms are more likely to be older, overweight, etc .
In order to see whether Friedman's curve was still useful, a 2010 research study examined labor records from more than 62,000 women across the US. This study found that for women who go into labor on their own, labors tend to be much slower than in 1955. Most women do not start dilating rapidly at 3cm as Friedman had found, and many women went for long periods of time without any dilation. In and of themselves, today's longer labors have not been shown to generate increased risk of harm to baby or mother. However, if labor progress is measured by old standards, today's women are more at risk for medical interventions aimed at speeding up labor.
New Standards
In 2013 the definitions of normal labor and arrested labor were updated to reflect recent research. It is recognized that active labor may not begin until 6cm dilation, and the new definitions make it more difficult to diagnose arrested labor. It is hoped that these new definitions will decrease the rate of preventable C-sections.
The new standards make it more likely that families will be able to follow the Healthy Birth Practices promoted by Lamaze International, in particular Healthy Birth Practice 1: Let Labor Begin On Its Own and Healthy Birth Practice 4: Avoid Interventions that Are Not Medically Necessary.
Most importantly, the new standards do a better job of recognizing that every woman is different, and that labor does not progress in the same way or at the same speed for everyone. Women's bodies are uniquely designed to undergo the process of pregnancy and labor, and in most cases can get the job done well without much intervention.
