New labor-tracking tool proposed to reduce C-sections in first-time moms

March 14, 2012 by Emily Caldwell

Researchers have designed a new version of a labor-tracking tool for pregnant women that they predict could reduce the use of hormonal intervention during labor and lower the number of cesarean sections performed on low-risk, first-time mothers.

The tool, called a partograph, takes into account the most recent research findings that suggest labor is not a linear process, but is instead slower during earlier labor and accelerates gradually as labor advances. A diagnosis of abnormally slow labor is the No. 1 reason that C-sections are performed in low-risk births by first-time moms.

A partograph is a printed graph on which a clinician can plot cervical dilation and the baby's descent to determine whether labor is progressing normally or if intervention might be needed.

The researchers, lead author Jeremy Neal of Ohio State University and co-author Nancy Lowe of the University of Colorado Denver, hope their partograph could be computerized or designed as a smartphone application.

When labor is considered too slow, often prescribe oxytocin to speed up the process. Oxytocin, known by the brand name Pitocin, is a hormone that stimulates uterine contractions. Research suggests that clinicians use it to speed up labor in about 50 percent of births by first-time mothers.

The term for an abnormally slow labor is dystocia. But no precise definition of dystocia exists, so it means different rates of labor for different clinicians. Though the use of oxytocin in cases of dystocia is intended to reduce the chances for a cesarean section, studies show that the hormone doesn't have that effect.

Neal and Lowe predict that if their partograph were adopted widely in the , dystocia diagnoses would be limited to only the slowest 10 percent of first-stage labors; oxytocin interventions would drop by more than 50 percent; and cesarean sections performed because of dystocia would decrease by more than 50 percent. Currently, more than a quarter of births by low-risk, first-time mothers result in .

"Dystocia is known to be over-diagnosed, which leads to unnecessary intervention, including cesareans," said Neal, an assistant professor of nursing at Ohio State. "We can tackle this issue by giving dystocia a clinically meaningful definition. This would go a long way toward preventing unnecessary cesareans for first-time moms which would, in turn, increase their chances of having successful labors and vaginal births for second, third and fourth deliveries as well."

Neal and Lowe are preparing to lead a pilot study of their partograph's effectiveness. Their proposal was published in a recent issue of the journal Medical Hypotheses.

Of the 4 million births in the United States each year, about 40 percent of babies are born to first-time moms. This partograph is designed for in-hospital labor assessment of first-time mothers with normal pregnancies whose labor has begun spontaneously.

Labor trends have changed since the 1950s, but Neal asserts that studies from that era still influence clinician expectations today. These older studies suggest that in first-time mothers, the cervix should dilate about 1.2 centimeters per hour once it has dilated 4 centimeters and until it has opened to 9 centimeters. Birth takes place at 10 centimeters, when the cervix is considered fully dilated.

"Clinicians tend to have an expectation that change in the cervix during labor is linear, with a dilation rate of 1 centimeter per hour often being considered to be the slowest acceptable rate of cervical change," said Neal, who also is a certified nurse-midwife. "However, these criteria are based on work started in the 1950s and ended in the 1970s that just doesn't fit the labor patterns of women today, for whatever reason. Research from the past two decades shows us that labor is not typically linear and rates of cervical change from one centimeter to the next are commonly much slower than 1 centimeter per hour. Clinging to defunct dilation expectations leads to unnecessary interventions during labor."

Neal said concerns over slow labor represent a "gray area" in labor assessment – some believe prolonged labor can cause distress for the baby, especially in developing countries where sophisticated fetal monitoring is less likely to be available, while others associate the use of oxytocin with adverse effects that include worrisome changes in fetal heart tones.

But what is undisputed is that dystocia, despite its vague definition, is the primary contributor to for low-risk, first-time moms. And with those come typical risks for bleeding and anesthesia complications associated with surgery as well as long-term risks for painful scarring, stillbirths and spontaneous abortions in subsequent pregnancies, future placenta attachment disorders and uterine rupture – and many of these risks are not commonly discussed with patients, Neal said.

Partographs have existed since the 1970s, and they are routinely used in most other countries, but have not taken hold in the United States. Neal describes this proposed partograph as more physiologically based than existing partographs, which continue to describe labor as a linear process.

"Because we don't use partographs in the United States, it will take some work to get this up and running in the U.S., but that is our goal," Neal said. "We want to positively impact birth outcomes for moms and babies as well as long-term health for women in the U.S. If our partograph were to spread to other countries, that would be fantastic, too."

The partograph is not intended for use until a woman is in active labor – which also can be difficult to define. In general, active labor begins when uterine contractions cause the cervix to be dilated to between 3 and 5 centimeters. Women admitted to hospitals before active labor has begun are almost twice as likely to receive oxytocin than are women admitted in active labor.

The tool consists of a chart featuring time passed on the x axis and cervical dilatation and the baby's descent on dual y axes. The most distinctive feature of this new partograph, however, is that it takes into account the hyperbolic curve that typifies most labors. Previous partographs have predicted that labor progress will be plotted in a straight line.

The proposed partograph features a dystocia line, indicating that when plot points appear to the right of that line, a dystocia diagnosis and associated interventions are appropriate.

"Our 'dystocia line' is not meant to indicate increased risk of adverse outcomes for women who cross to the right of it. Instead, it is designed to improve the safety of those who do not cross this line by decreasing unnecessary use and cesarean sections," Neal said. "Cesarean sections are clearly indicated for some women, but if we're doing a high volume of unnecessary cesareans on first-time moms, then we are simultaneously affecting the future obstetrical course for those women since a primary cesarean is most commonly followed by repeat cesareans in subsequent pregnancies. Long-term health risks go up with each subsequent cesarean."

In addition to their pilot study, Neal and Lowe recommend that a large, multicenter clinical trial is needed to test whether their predictions about the partograph's effectiveness are supported by actual childbirth outcomes.

Explore further: Drug speeds up slow labor but doesn’t prevent C-sections

Related Stories

Drug speeds up slow labor but doesn’t prevent C-sections

July 15, 2011
A new Cochrane review says that oxytocin, a medication often used to quicken slow-paced labor in its early stages, doesn’t boost the prospects for normal births. Riskier births that required cesarean section or the use ...

Unnecessary induction of labor increases risk of cesarean section and other complications

March 6, 2012
A new study published in the journal Acta Obstetricia et Gynecologica Scandinavica reveals that induction of labor at term in the absence of maternal or fetal indications increases the risk of cesarean section and other postpartum ...

Study finds pregnant women with prior cesarean choose the delivery method preferred by their doctor

February 9, 2012
In a study to be presented today at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting, in Dallas, Texas, researchers will report findings that women who have undergone one prior delivery via ...

Inducing labor is not associated with higher rates of cesarean sections

June 20, 2011
A new study published in the international Nordic journal Acta Obstetricia et Gynecologica Scandinavica (AOGS) reveals that inducing labor in the weeks around term, or from week 39 to week 41, is not connected with higher ...

Researchers pinpoint reasons for dramatic rise in C-sections

June 22, 2011
(Medical Xpress) -- In one of the first studies to examine the reasons for the rising number of women delivering their babies by cesarean section, Yale School of Medicine researchers found that while half of the increase ...

Recommended for you

Women exposed to smoke while in womb more likely to miscarry

July 13, 2017
Women exposed to cigarette smoke while in their mothers' wombs are more likely to experience miscarriage as adults, according to new research from the University of Aberdeen.

Lack of a hormone in pregnant mice linked to preeclampsia

June 30, 2017
(Medical Xpress)—A team of researchers from Singapore, the Netherlands and Turkey has isolated a hormone in pregnant mice that appears to be associated with preeclampsia—a pregnancy-related condition characterized by ...

Aspirin reduces risk of pre-eclampsia in pregnant women

June 28, 2017
Taking a low-dose aspirin before bed can reduce the risk of pre-eclampsia, which can cause premature birth and, in extreme cases, maternal and foetal death.

The biology of uterine fluid: How it informs the fetus of mom's world

June 22, 2017
A developing fetus bathes in a mixture of cellular secretions and proteins unique to its mother's uterus. Before fertilization, the pH of uterine fluid helps create a conducive environment for sperm migration, and afterward, ...

New clues in puzzle over pre-eclampsia and cholesterol regulation

June 21, 2017
Scientists studying a mystery link between the dangerous pregnancy complication pre-eclampsia and an increased risk of heart disease in later life for both mother and child have uncovered important new clues.

Are maternal hormones different when carrying a boy or a girl?

June 15, 2017
With advances in prenatal testing it's now possible to find out whether a pregnancy will result in a male or female baby as early as eight weeks' gestation.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.