Physiologic Labor

Timing Labor

I am currently preparing to take the midwifery certification exam.  Today I was reviewing intrapartum and was struck with the strange realization that I was on the “other” side of the fence.

When I first trained as a childbirth educator, I had it drilled into me that time limits in labor were arbitrary. Because they were arbitrary, they were useless.  Story after story in the natural birth web sphere seemed to prove this philosophy. Doula’s and childbirth educators shared tips on how to know if the time limit you were given was real, or just or convenience. Friedman was blamed for the problem with his 1 cm per hour average, and his theories were thrown out as invalid.

As I reviewed today, I came to the data on Friedman. I realized I’ve grown to respect his philosophy, even if I want better data to make final labor cut-offs.  While I was trained to see the Friedman curve as the way hospitals and doctors get patients to do what they really want, I have come to understand the usefulness of a tool to help me ensure labor is progressing.  But I didn’t get there immediately, I had some learning to do first. Part of that learning was the importance of the Partogram in global public health efforts.  The other part was that I didn’t have the full story on Friedman.

For example, Friedman’s active stage didn’t start until at least 3-4 cm, and it ended at 8-9 cm. which means the 11.7 hours as the upper end of normal active phase for nullipara’s wasn’t the whole picture – in other words, he wasn’t saying 12 hours for labor. The latent phase wasn’t prolonged for nulliparas until it reached 20 hours.  8-10 cm was called the deceleration phase, which wasn’t “prolonged” in a nullipara until 3 hours. Second stage began at 10 cm.  So if you do all that math, contractions can start at midnight, and I can reach 10 cm at midnight the next day (24 hours later) and Friedman wouldn’t necessarily call my labor disordered. Second stage had it’s own timing and its own method of assessing progress with fetal descent – a baby that had no descent in one hour needed attention.

The second thing I had to learn was that Friedman was interested in identifying women who were having problems with labor – which I think is a pretty good thing to want to know how to do.  While no one wants to say labor has to fit a particular schedule, labor not really progressing well can be an alert mechanism to look more closely at what is happening.  Friedman defined several ways a labor may not be progressing well, it may be  protracted, or arrested.  Each of these had their own timing cut-offs.  And the biggest thing they didn’t teach me as a childbirth educator, “falling off the curve” is not an instant intervention as far as Friedman is concerned.  There is a four hour wait time before intervening.  On the partogram the woman “falls off the curve” at the alert line, then intervention begins at the “action” line.

What is even more interesting to me now is that I realize the response to the “slow” labor is not something arbitrarily chosen.  As a midwife, the slower labor alerts me that the patient may have a problem and I assess the situation.  Depending on my assessment (is she having regular contractions? are the contractions strong? what position is the baby? ) I will make decisions about most appropriate course of action. Now that I am on this side of midwifery school, I understand why physicians and midwives do not always make the same suggestion. And that even though it looked like it to me before, the management (at least in the cases I’ve been with) is not arbitrary.

So overall, I think I like Friedman’s idea to identify and evaluate women who are far enough away from an average to warrant a high suspicion   Now if we could just get some great data on what these averages and upper limits are in natural, epidural and induced or augmented labors.




Jennifer Vanderlaan (Author)