In other words, some doctors don't wait long enough for labor to progress on its own before declaring that a cesarean is needed.
The problem of "failure to wait" cesareans is often particularly prevalent in women of size and may be one reason for a higher rate of cesareans in "obese" women.
A Lack of Patience for Women of Size
Since "failure to wait" is especially common in induced labors (recent research shows that "half of cesarean[s] for dystocia in induced labor were performed before 6 cm of cervical dilation"), and since women of size are induced at far higher rates than other women, discussions about "failure to wait" cesareans in this group are very important.
Adding into this is the fact that labors tend to be longer in women of size, perhaps reflecting more malpositioned babies or induction for longer gestations (i.e., bodies not quite ready for labor yet).
If labor tends to be longer in women of size and caregivers do not allow for that, more "failure to wait" cesareans are going to occur.
For example, Pevzner 2009 found that induced labors took longer and required more induction drugs in "obese" women. Even when controlled for induction, Nuthalapaty 2004, and Hamon 2005 showed that "obese" women had longer labors, especially in the first stage.
In addition, Vahratian 2004 showed that the slower duration was concentrated around 4-6 cm of dilation, exactly when most "failure to wait" cesareans are performed. They concluded:
Labor progression in overweight and obese women was significantly slower than that of normal-weight women before 6 cm of cervical dilation. Given that nearly one half of women of childbearing age are either overweight or obese, it is critical to consider differences in labor progression by maternal prepregnancy BMI before additional interventions are performed.In other words, doctors need to wait a little longer in women of size to give labor every chance to progress further before performing a cesarean.
Another classic example of "failure to wait" is found in the first VBAC study on "obese" women, which is often cited as a reason not to let very fat women try to VBAC. The study found only a 13% success rate in this group, and so it was widely concluded by many authors that very fat women were not appropriate candidates for VBAC. (Don't worry; later studies have found much higher success rates.)
A closer look at the study reveals that there were only 30 women in the trial of labor (TOL) group, certainly not a large enough sample size on which to make sweeping policy decisions for a whole demographic group. The study also showed that, of these women, 57% had their labors induced, which research clearly shows lowers the rate of VBAC success. (In the 13% VBAC study, none of the women who had their labors induced had a VBAC; all the VBACs went into labor spontaneously.)
Most tellingly, the average dilation at the time of the decision for repeat cesarean during labor was 4.5 cm. This shows that these women of size were not really given an adequate chance at labor, and were sectioned far too early, as is so common in the labor management of "obese" women.
Is it any wonder that the women in this study only had a 13% VBAC success rate? Their doctors clearly did not believe that very fat women could give birth vaginally on their own, and so induced more than half of them, despite all the evidence showing induction lowers VBAC success rates. Furthermore, they gave up on the trial of labor very early, before the women had really even reached the active stage of labor.
Although I'm sure the physicians justified intervening earlier in order to avoid difficult and risky emergency surgery later on, it shows a troubling pattern in not letting fat women even have an adequate trial of labor before jumping to a surgical conclusion.
Yes, surgery in very fat women is harder and takes longer, so it is understandable that doctors don't want to wait until there is an emergent situation before intervening. But more and more, they are moving towards only giving "obese" women a token trial of labor (if they let them labor at all), and moving prematurely to a surgical solution if the baby doesn't practically fall out. This is not a reasonable alternative.
Given the increased risks of surgery in women of size and the long-term implications of surgical births, I would argue that the better solution is not to section fat women prematurely, but instead to give fat women every chance to deliver vaginally by awaiting spontaneous labor whenever possible, and to apply a tincture of patience, knowing that labor may simply take a little longer in women of size.
As long as mother and baby are doing well, a tincture of patience is the best option for long labors in many women, and may be particularly appropriate in women of size.
"Failure To Progress" cesareans are far too often "Failure To Wait" cesareans, and especially so in women of size.
Here's the abstract of that new study:
Zhang J et al. The Consortium on Safe Labor. Contemporary Patterns of Spontaneous Labor With Normal Neonatal Outcomes. Obstet Gynecol. 2010 Dec;116(6):1281-1287.
OBJECTIVE: To use contemporary labor data to examine the labor patterns in a large, modern obstetric population in the United States.
METHODS: Data were from the Consortium on Safe Labor, a multicenter retrospective study that abstracted detailed labor and delivery information from electronic medical records in 19 hospitals across the United States. A total of 62,415 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor, stratified by cervical dilation at admission and centimeter by centimeter.
RESULTS: Labor may take more than 6 hours to progress from 4 to 5 cm and more than 3 hours to progress from 5 to 6 cm of dilation. Nulliparous and multiparous women appeared to progress at a similar pace before 6 cm. However, after 6 cm, labor accelerated much faster in multiparous than in nulliparous women. The 95 percentiles of the second stage of labor in nulliparous women with and without epidural analgesia were 3.6 and 2.8 hours, respectively. A partogram for nulliparous women is proposed.
CONCLUSION: In a large, contemporary population, the rate of cervical dilation accelerated after 6 cm, and progress from 4 cm to 6 cm was far slower than previously described. Allowing labor to continue for a longer period before 6 cm of cervical dilation may reduce the rate of intrapartum and subsequent repeat cesarean deliveries in the United States.