In Induction of Labor

The Stir picks up on a U Penn press release extolling a combo method of inducing labor that decreases labor duration by 4 hours compared with inducing with either of its components alone. I get why this is good for hospitals. Increasing throughput improves their bottom line, a benefit the Stir article and press release frame as reducing costs, although this makes no sense since hospitals don’t charge by the hour. That’s not their main point, though. They’re selling the 4-hour savings as a blessing for women because it enables them to “snuggle with baby sooner rather than later” (the Stir article) and could “spare [U.S.] pregnant women more than 100,000 days of labor annually,” (the press release). Is it?

Ask any mom who’s had a short labor, and she’s likely to tell you having long, hard contractions coming on top of each other right from the start was no boon. And while we can fix the mom’s problem with an epidural—in which case she won’t care about how long the labor is—what about the baby? Babies are designed to tolerate the stress of the normal process; in fact, it’s good for them. But what happens when you’ve forced labor on a cervix that isn’t ready to open and a uterus where the uterine muscle cells haven’t yet linked up to work together effectively? And what happens when you push that process as hard as you can because you’ve decided that faster is a virtue? Let’s look at what did happen.

Investigators randomly allocated 491 women to labor induction using one of four techniques: misoprostol (A.K.A. Cytotec) alone, inserting a balloon catheter into the cervix alone, balloon catheter + misoprostol concurrently, or balloon catheter + oxytocin (Pitocin or “Pit” A.K.A. Syntocinon) concurrently. All women had cervixes that were still long, firm, and closed (Bishop score range 2-4 on a scale of 10). All women could be given oxytocin if needed after labor was initiated, and most were (69-98%, depending on group). The hospital used an Active Management protocol for oxytocin, which meant upping the dose every 15 minutes to a maximum of 40 milliunits/min. For comparison’s sake, the oxytocin package recommends increasing the dose every 30 to 60 minutes and states that rates of 6 milliunits/min are equivalent to what the body produces naturally and that rates exceeding 9-10 milliunits are rarely needed.. Rupturing membranes, another stressor because it removes the cushioning effect of amniotic fluid, was at the discretion of the doctor; however, it was recommended once cervical dilation reached 5 cm. Median induction-to-delivery time (half delivering before and half after) favored the misoprostol-balloon combo (13.1 hrs misoprostol-balloon; 14.5 hrs balloon-oxytocin; 17.6 hrs misoprostol; 17.7 hrs balloon), although the balloon-oxytocin combo ran a close second, and more women delivered before 12 hr (45% vs 26%) and before 24 hr (88% vs. 70%) in the misoprostol-balloon group than in the balloon only group.

As Thornton & Lilford put it back in 1994, “An accelerated labor is as safe as a streamlined parachute. As it turned out, though, assignment to the balloon catheter-misoprostol group didn’t increase occurrence of adverse events compared with the other groups. The study authors take this as vindicating the faster technique (although it may be that more intense labor was more problematic whichever group the women were in), but all it really means is that the groups did equally poorly:

  • One in five women (20%) needed a drug to calm contractions.
  • Approaching half of the 1st-time mothers had a cesarean (40%).
  • Half the cesareans (52%) had “nonreassuring fetal heart rate” listed as a reason. Almost all the rest had some variation on “baby wouldn’t come out in the time we allowed” as a cause.
  • Approaching one in 10 women (7%) experienced one or more of the following: anal sphincter tear; blood transfusion; uterine infection; wound separation or infection requiring re-closure, antibiotics, or both, and some women (3%) needed to be readmitted to the hospital.
  • One in 10 babies (11%) was admitted to intensive care, of whom a third spent more than 48 hr.

Granted, some of this may have been unavoidable because many of the inductions were for medical indications, but you have to wonder how much better off these women and their babies might have been had they been allowed to begin labor and have it proceed on its own or if their doctors had waited for the cervix and uterus to be ready before inducing labor, refrained from rupturing membranes, and used an oxytocin regimen that mimicked physiologic processes—especially considering that the babies were likely to be less resilient. As Tracy Donegan, midwife and founder of Gentle Birth, puts it in the Stir’s “Let’s hear from the other side” section of the article:

It’s . . . worth considering what percentage of the reported 100,000 hours [of labor spared each year . . .] could be reduced by awaiting a spontaneous start to labor whenever possible. . . . Women who have a clinical need for induction should be supported to have the safest and most positive birth possible. This means moms will have an in-depth discussion with full disclosure on the risks/benefits of each method of induction rather than being influenced to choose the option that suits her care provider or hospital due to time and cost savings. Moms would also be informed that induction of labor is not always successful and is associated with increased risk for Cesarean birth and its associated complications for first-time moms.

Amen to that.


Quote Source: Thornton JG, Lilford RJ. Active management of labour: current knowledge and research issues. BMJ 1994;309(6951):366-9.

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