Evidence-Based Medicine: Labor Induction

What is labor induction?

Artificial induction begins contractions and dilation of the cervix, essentially starting labor before it begins on its own.  Breaking the water, Foley balloons, prostaglandin gels and tablets, and IV synthetic oxytocin (Pitocin) are all methods of labor induction, with Pitocin being the most popular.

Induction was originally used to deliver babies in women with small pelvises (common side effect of Rickets, a Vit D deficiency) and in cases of pre-eclampsia.  Like many medical practices, it was at first very risky, and was only done when it was more dangerous for the woman to remain pregnant than to induce. Now it is relatively safe and quite common, with over a third of all births occurring through artificial beginnings. [1]

What is the current approach to induction?

Once upon a time, obstetricians believed that prophylactic (preventative) inductions should be practiced in all pregnancies.  Instead of being left at the mercy of spontaneous labor, doctors can now schedule it.  And while it is (fortunately) not practiced in all labors, it is a growing trend, and can even be performed without medical indication (elective).  The most common reason given for induction is “post dates,” or overdue, followed by a maternal health problem, a desire to get the pregnancy “over with,” and concern about the baby’s size.  Pitocin is used in 80% of medical inductions, and most women experience more than one induction method, usually breaking the waters. [2] The American College of Obstetrics and Gynecology (ACOG) recommends against induction before 39 weeks in the absence of a medical indication. [3]

What does the evidence suggest about induction?

Pitocin has been approved by the Federal Drug Administration as safe for use, but there is a noted increase in epidural use, interventions, and c-sections when an induction is attempted. [4] [5]  However, inductions are often unsuccessful, even when combined with amniotomy (breaking the water), which may increase a woman’s chance of a cesarean section. The ideal rate, calculated by the World Health Organization (WHO) is 10%.  [6]

One of the most common reasons given by women and obstetricians for inducing is when a woman is overdue or “post-dates.”  Research has shown a VERY slight increase in fetal death after 41 weeks, but the absolute risk is quite low regardless.  This means that the risk of the baby dying without the induction was also quite small, but induction reduced the risk further. [7]  The risk increases even more after 43 weeks, but very few women ever go that long, even without induction. [8]

Another reason some pregnancies are not allowed to go beyond the due date is the fear that the baby will grow too large to fit through the mother’s pelvis.  However, despite this being a common reason given for induction, there has actually been no evidence to suggest that induction due to suspected macrosomia (big baby) has any benefit to mother or baby.  Also, due to the documented inaccuracy of ultrasounds for determining due date and size of the baby [9][10], induction carries the risk of the baby being premature, or at a low birth weight. [11]

What are the risks of labor induction?

Although Pitocin, one of the most common induction drugs, as well as many other methods of induction, have been proven safe to use, the dangers of induction are more about the resulting interventions that may occur as a result.  For example, the stronger and more frequent contractions that happen with artificial induction cause most women to request an epidural, which while relatively safe, does carry it’s own complications.  The contractions themselves may increase “fetal distress,” since the baby does not have the opportunity to recuperate between contractions, and “fetal distress” is more likely to result in an instrumental (forceps or vacuum) or surgical delivery.  Again, it’s not the induction itself that causes the problem, but rather the resulting “cascade of interventions” that can follow. [12]

The unnaturally strong, long, and frequent contractions can put undue stress on the uterus, leading to higher rates of postpartum hemorrhage and uterine hyperstimulation and rupture.  Women attempting a Vaginal Birth After Cesarean (VBAC) should be especially cautious about using any artificial induction methods, as they are at a higher risk of hyperstimulation and rupture [13], which can be fatal.

What is the alternative?

If at all possible, WAIT.  Studies have shown that in the final days of pregnancy, your baby’s brain and lungs are still developing.  Even just one day could make the difference in terms of your child’s long-term health.  One current theory is that, when your baby’s lungs are ready to breathe on their own, they release a protein that triggers labor to begin. [14] Unless it absolutely essential to induce, you should try to give your baby every opportunity to develop.

Natural induction methods would also be an option, such as breast stimulation [15], acupuncture [16], or good-old fashioned nooky[17].

Final Thoughts

I am always just a little bit nervous whenever I know someone who is being induced.  Too many women I’ve known have experienced C-Sections as a result, and too many babies have had complications.  Just because it is possible to plan your baby’s birthday down to the hour doesn’t make it preferable to waiting for natural labor.  The birth process is amazingly complex, and rushing any part of it could have short-term or even long-term consequences that we have yet to understand.  You absolutely have the right to refuse induction if you don’t believe it is in your or your baby’s best interests.

Conspiracy Theory Time:

Inductions are better for business.  Data from the CDC shows an increasing trend toward births occurring during daylight hours Monday through Friday, indicating that inductions are done at least partly for the convenience of the doctor. [18]

Think about it from the physician’s perspective…Let’s say you have a very busy practice, and you’re trying to have a quality of life, maybe you’ve got a young family, you don’t want to be running out every night to deliver a baby, or not coming home in time for dinner, missing everything that your child is doing. So what happens is you try to get all the births in between 9 and 5, and to do that, you have to make sure nobody goes into spontaneous labor; and to make sure of that, you have to induce them all early. Or let’s say this is the day you have to be on call, it’s best then for you to induce three or four people on that day because you can get them all done at once. Those three or four people aren’t going to call you on the weekend, they’re not going to call you in the middle of the night, they’re not going to interrupt your office hours, they’re not going to give birth at any time that’s inconvenient.

Some say scheduling births is all doctors can do to maintain their level of income while larger and larger portions of it are earmarked for malpractice insurance premiums. If a doctor misses a birth, he loses revenue. Even if an induction doesn’t work, a cesarean is waiting. And from incision to sutures, a cesarean takes less than an hour. In addition to time management, the looming fear of lawsuits drives doctors to act rather than to wait. “Doctors are practicing more defensively,” says Bernstein. It’s irrelevant that an induction might lead to a cesarean. “To be blunt, you don’t get sued when you do a cesarean,” he says. “You get sued when there’s a damaged baby. And if they can find any reason that the woman should have been delivered earlier, then it doesn’t matter whether the damage had anything to do with how you managed the baby. All that matters is did you do everything that you could have possibly done? And that causes doctors to say, `Well, it’s got to look like I’ve tried my best. And trying my best would be to deliver the baby.’ So you explain to the mother that the fluid’s a little low.

Jennifer Block. Pushed: The Painful Truth About Childbirth and Modern Maternity Care (pp. 42-43). Kindle Edition. [*]

Resources

Born in the USA: How a Broken Maternity Care System Must Be Fixed to Put Women and Children First (Wagner, 2008)

The Cochrane Library

Listening to Mothers Survey (2005)

Pushed: The Painful Truth About Childbirth and Modern Maternity Care (Block, 2008)

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One Comment on “Evidence-Based Medicine: Labor Induction”

  1. […] often downplayed or left out, especially if it is a repeat surgery.  Other interventions, such as induction/augmentation and epidurals also have risks which are rarely discussed in […]


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