Rewriting the Rules of ‘Normal Labor’: What Does This Mean for Mothers?

One of the popular claims circulating on some parent forums is that medical professionals aren’t giving women enough time to labor before moving to deliver a baby. Many claim that doctors do this because they are motivated by time pressures, financial incentives, and organizational pressures. Relatively recently, changes to clinical guidelines have increased labor times – but with the secondary effect of increased birth trauma rates.

Rewriting the Rules of 'Normal Labor' - Birth Trauma and Lowering Rates of C-Section Intervention In 2014, the American Congress of Obstetricians and Gynecologists (ACOG) changed one of the standard technical charts used by practicing OB/GYNs commonly known as a “labor curve,” which defined what normal vs. arrested labor looked like. This chart help doctors understand how long women can labor for before interventions are necessary for the health of both mother and child. If labor stalls for too long, it puts both at risk for injury.

Although swapping one reference chart out for another might sound like a small difference, what it means for laboring mothers is highly significant. Changing the labor curve may mean a lower C-section rate. However, this lowered C-section rate corresponds with an increase in birth trauma rates. Such a trade-off is unacceptable, as it puts babies at risk in the pursuit of lower intervention rates.

Replacing the Gold Standard with Unproven Guidelines

Landmark researcher Emanuel A. Friedman, M.D. introduced the Friedman labor curve in 1955. It was used as the gold standard for figuring out whether labor was progressing or stalled until 2014, when ACOG developed a new set of guidelines. This new set of standards lengthened labor and allowed fewer diagnoses of ‘arrested labor.’ The problem with this is that a decreased diagnosis rate does not change the reality of when a C-section may be needed. As a result, the risk of traumatic injury has gone up significantly.

The Friedman curve was designed to identify which laboring mothers had a ‘reduced likelihood of a safe vaginal delivery’ by identifying which mothers had an ‘arrested labor.’ Arrested labor is associated with a bigger risk of neonatal morbidity and mortality, while a labor progressing normally had a much lower risk of adverse outcomes. The curve helps guide decision-making – if a mother’s cervix was not dilating progressively in the active phase of labor 1.2 cm/hr (for women with no prior childbirths) or 1.5cm/hr (for women who have had children before), C-sections were recommended to help prevent adverse outcomes like respiratory depression and issues stemming from oxygen deprivation.

In contrast, the new, unproven curve concluded that dilation in the active phase was more than twice as slow as the recommendation in the Friedman curve, and follow-up articles to this new curve further added that active labor began at 6 cm dilation (not 3 cm dilation, as Friedman had described). Under this new curve, 1.2cm/hr was considered the average rate at which dilation occurred, reframing the numbers in a near-reversal of Friedman’s conclusions: what Friedman found was ‘slow labor’ was re-labeled ‘normal’ by this new curve.

An Unfounded ‘New Normal’

In 2012, ACOG, the Society for Maternal Fetal Medicine, and the National Institute for Maternal and Child Health held a meeting where they endorsed this new definition of normal labor and arrested labor, under the premise that women were being unduly diagnosed with failure to progress. This led to the publication in 2014 of the Obstetric Care Consensus, “Safe Prevention of the Primary Cesarean Section Delivery.” This document replaced the Friedman curve and 60+ years of supportive evidence with a new and dangerously flawed methodology.

The new guidelines stated that C-sections for active phase arrest in the 1st stage of labor was only really needed for women dilated more than 6 cm with ruptured membranes who fail to progress over 4 hours, or for women who have had 6 hours of Oxytocin drip with low uterine activity and no cervical changes. On top of this, the standards also changed what a ‘prolonged latent phase’ meant: a labor longer than 20 hours for women who haven’t had children before (or 14 hours for those who have) still was not a reason to consider C-section.

Cohen and Friedman, the researchers who developed the Friedman curve, examined the new guidelines and found serious cause for concern, finding that the new guidelines had substantially mischaracterized their work and used ‘curve-cutting techniques which miss[ed] the entire point of using labor curves rather than the clock to assess the normality of progress in cervical dilatation and fetal descent.” They further cautioned that these new standards were not evidence-based, as they could not be ‘reconciled with data from direct observation of dilatation and descent or with data from several dozens of publications from investigators around the world…”

The Friedman curve was a simple and effective method for helping doctors make clinical recommendations, allowing them to recognize and quantify the effects of parity, analgesia, obesity, prior C-section effects, maternal age, fetal position and presentation over 60 years – things the new, unvalidated methods could not do. Despite this, ACOG continued disseminating unsound replacement guidelines to artificially force down C-section rates.

Unintended Effects: Forcing Down C-section Rates Increases Birth Trauma Risk

The new guidelines did have the effect of lowering the C-section rate a few percentage points. Unfortunately, this came at the expense of neonatal health, with a more than two-fold increase in very low APGAR scores, a common indicator that a baby is not doing well after birth. Further, the new guidelines elicited concern that the best interests of mother and child were being sacrificed in the name of C-section reduction:

“[W]e believe our specialty has too hastily adopted wholly new guidelines for the assessment and management of labor, and has used a reduction in the cesarean rate, rather than optimization of maternal and neonatal outcomes, as the grail to be sought.  The long labors endorsed by the new guidelines…would result in gratuitous exposure of fetus and mother to potentially injurious forces of labor…That is not a trade-off with which we or the women who entrust themselves to our care should be comfortable…There is a great deal at stake for the well-being of women and children in adopting labor management guidelines. It is essential that we do so thoughtfully and judiciously.”

Head Compression and Prolonged Labor: The Result of a New ‘Wait and See’ Approach

We know that hypoxia-ischemia causes HIE, and that this is directly caused by excessive head or umbilical cord compression, whether it is due to the forces exerted by forceps, vacuum extraction, dysfunctional labor,  uterine hypercontractility or other factors. Babies have compensation mechanisms to help protect the brain from intermittent decreased blood flow during labor, but in prolonged labor these mechanisms can fail, causing injury.

We also know that prolonged labor causes more cerebral compression (head squeezing) than normal labor, causing traumatic HIE. In a prolonged labor, babies’ heads can be repeatedly compressed by excessive uterine activity, marked molding, malposition and other factors. This compression can increase the pressure in the baby’s brain, collapsing the delicate network of cerebral arteries that supply much-needed oxygen. Landmark medical texts acknowledge the role that mechanical forces have on a baby’s brain, resulting in inadequate blood flow to the brain during labor, even if there is no obvious head trauma, bleeding or blood acidity.

Excessive head molding is one factor by which babies can have a brain injury, especially under circumstances of prolonged abnormal labor progress, high uterine activity, and ruptured membranes, and infants born with Oxytocin stimulation have much higher head molding than those without.

Rewriting the Rules of ‘Normal Labor’

A Misguided Attempt to Lower C-Section Rate Raised the Incidence of HIE and Birth Injury

We know that C-sections can decrease the risk of neurological harm to infants, especially if there is a prolonged or traumatic labor. ACOG’s new guidelines delay the point at which arrested labor is diagnosed and raises the threshold at which medical staff will consider a C-section, at which point it may already be too late to prevent neurological damage.

Waiting and taking a hands-off approach by rewriting the rules about what is a normal vs. a dysfunctional labor pattern does a grave disservice to mothers and children by exposing them to greater risk to injury. As a result of these changed labor guidelines, our firm has seen a huge increase in the number of HIE cases where babies have had significant head molding injuries resulting in catastrophic brain damage, but they do not meet the criteria for head cooling because they have apparently normal blood gas results. We’ve seen cases with prolonged or arrested labors where OBs do not move to a C-section, even with abnormal labor patterns.

These cases are preventable, and perpetuated by a careless, hands-off approach encouraged by a misguided attempt at lowering C-section rate. No child should suffer HIE, brain bleeds, strokes or brain trauma due to untested clinical guidelines. Lowering the C-section rate in general is an admirable goal in the abstract – but not at the expense of the infant’s and mother’s health and safety.

Video: Abnormal Labor Patterns

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