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)


Evidence-Based Medicine: Are Inductions Safe?

A couple weeks back, I researched the necessity of labor induction.  I learned that, according to the Listening to Mothers Survey from 2005, about 40% of all labors are medically induced.  I also learned that, according to birth experts Ina May Gaskin and Marsden Wagner, induction is only medically indicated in about 10% of births.  This means that about three-quarters of all women who are induced are doing so without medical indication.  If induction is perfectly safe, there would be no concern — so what does the research say?

The stats…

80% of medical inductions were done using a drug called Pitocin, a synthetic oxytocin, which causes the uterus to contract.  Other methods of induction include prostaglandin medications applied to ripen the cervix, stripping/sweeping the membranes, and “breaking the water”  (artificial rupture of membranes (AROM)).  Most mothers included in the survey were subject to 2 or more methods of induction, the most common combination being Pitocin and AROM.

Not only are many labors medically induced, but many are also augmented using the same methods listed above.  When these numbers are included, about 50% of women are given artificial oxytocin to either induce or augment labor, and 65% have their water broken.

The risks…

  • More painful labor — Common induction methods such as artificial oxytocin can lead to longer and stronger contractions that are closer together.  This means more pain for the mother during contractions, as well as a shorter period of time between contractions to recuperate.  This can quickly exhaust a laboring woman, not to mention tarnish her birth experience.  Many women whose labors are induced or augmented find an epidural to be a necessity.

“I went into labor on my own with my daughter, but was induced with my son.  With my daughter, I found that sitting in a warm bath made the pain very manageable, and I didn’t get the epidural until very late — 7 cm, I think.  With my son, I got an epidural at 3 cm — I just couldn’t stand the pain.”  — Annie, 31

  • Prematurity — Miscalculation of due dates can lead to a woman being induced before her baby is mature.  Iatrogenic (doctor-caused) prematurity is on the rise, and with it comes all the risks commonly associated with prematurity, such as breathing problems.  New research shows that the production of fetal lung proteins trigger labor — meaning that the baby triggers spontaneous labor when its lungs are ready to breathe.  Inducing without medical indication means your baby may not be totally ready to breath independently.  Labor should NEVER be induced before 39 weeks for this reason, and should ideally be around 42 weeks as long as the baby shows no signs of distress.
  • Fetal Brain Damage or Death —  The only time a fetus can get oxygen is during the rest period between contractions, so when those periods are shorter, the fetus gets less oxygen.  Lack of oxygen is associated with an increased risk of brain damage.
  • Maternal death —  According to Marsden Wagner’s book Creating Your Birth Plan, induction of labor is linked to higher rates of uterine rupture and amniotic fluid embolism (AFE), both of which are rare but usually fatal (80% of AFEs are fatal — 50% within the first hour after symptoms appear).  C-Section dramatically increases the incidence of both.  Many women who survive uterine rupture undergo hysterectomies and are unable to have any more children, and most that survive AFEs are severely brain damaged.  Fetal death is also common with both of these complications.
  • “Cascade of Interventions”A woman who is either induced or has her labor augmented artificially is at an increased risk of instrumental (forceps and vacuum-assisted) and surgical (c-section) interventions.  So even if the induction drug itself is considered safe (which Pitocin is), the risks associated with all other forms of intervention must be calculated as well.  While the more severe risks (uterine rupture, AFE, fetal brain damage) are relatively rare, the so-called “cascade of interventions” is fairly common.  A woman who is induced more than doubles her riskof having a C-Section.  A woman who goes in to be induced may find her plans for a low-intervention birth go awry very quickly.

 “I got induced at 41 weeks because they thought she was going to be too big too birth otherwise.  First came the Pitocin, then the epidural for the increased pain, which meant I was tethered to the bed with IVs, so I couldn’t move around.  Then my labor slowed down, and they broke my water to speed things up.  I went into labor thinking that I could manage an induction naturally, but instead I ended up with a C-Section because of failure to progress.”— Silvia, 26 

  • Interferes with Bonding/BreastfeedingArtificial oxytocin alters the mother’s natural hormones during and after birth, potentially affecting her ability to bond with or breastfeed her baby.  Any other interventions she experiences (such as cesarean) can also interfere.  

“When my son was born, I felt like he belonged to someone else.  I kept waiting for that overwhelming feeling of attachment I knew I was supposed to feel, but it just didn’t come — I felt like I was just going through the motions for weeks.” — Patty, 29

What is the alternative?

So if induction carries with it the risks listed above, it could be argued that elective induction is not in the best interest of the mother or baby.  So what’s the alternative?  Well, waiting.  Just remember, every day your baby “cooks,” s/he will be a little bit stronger, a little bit healthier.  As we talked about last week, babies can and have been (vaginally) born past their due dates perfectly healthy.   Trust your baby, and trust your body to go into labor on your own — it’s better for both of you!


Evidence-Based Medicine: Is Induction Necessary?

During my last month of pregnancy, I had a few “false alarms,” where I was convinced I was in labor, but it turned out I wasn’t.  I was so anxious to meet Sweet Pea, a little nervous about what labor would actually feel like, and it started to do weird things to my brain.  After our third false alarm, my husband and I finally sat down and accepted the reality that we had no control, and that Sweet Pea would come when she was ready.  We knew that every day she “cooked,” the healthier she would be.  I went to bed that night at peace, knowing that the best thing I could do for her was to be patient.  The next morning, I woke up in labor – at 39 weeks on the nose.

Many first time mothers experience the same kind of anxiety and anticipation that I did, but the weeks stretch on an on, even surpassing their due date.  And those women and their doctors are talking more and more about artificial induction, using labor-stimulating drugs like Pitocin.  A study from 2006, featured in the New England Journal of Medicine, found that 40% of low-risk, first time mothers were induced into labor.

Induction is definitely a growing trend in America.  But is this trend necessary to improve the outcomes for mothers and babies?  Are there situations where induction is medically indicated?  And how much of this trend is based on convenience — either for the mother or doctor?

When is induction medically necessary, improving the outcomes for mothers and babies?

According to Ina May Gaskin’s Birth Matters, up to 10% of all labors may call for labor induction.  She lists specific circumstances that may call for induction, such as:

  • cancer
  • hypertension
  • diabetes
  • kidney disease
  • IUGR (intrauterine growth restriction)
  • significant decrease in amniotic fluid
  • intrauterine fetal death (followed by a long (weeks, not days) wait for labor to begin)

Marsden Wagner (perinatologist, and author of Born in the USA) adds two other conditions:

  • documented placental malfunction (placenta losing its ability to nourish the fetus)
  • deteriorating preeclampsia (high blood pressure during pregnancy)

According to Gaskin and Wagner (both specialists in their fields), under these conditions, induction actually improves the outcome (as opposed to spontaneous labor).  But they both state that only about 10% of all pregnancies need to be medically induced.  And when you add up the statistics for each of the above circumstances, it comes very close to 10% of pregnancies.  But, according to Childbirth Connection‘s 2005 Listening to Mothers Survey, half of all pregnant women experience induction.  So why the major discrepancy?

You may notice that two of the most commonly-given reasons for induction — postdate (overdue) pregnancy and big babies (macrosomia) — are not listed.  This may explain the difference in recommendation versus reality.  Let’s see what the evidence says about those two reasons.

Induction Due to Post-Dates (Overdue)

This is the normal distribution for gestational age.  Notice when the largest majority of babies are born — 40-41 weeks.  And approximately the same percentage give birth between 41-42 weeks as do 39-40.   And this is all with spontaneous labor!

I think this about says it all.

Normal, low-risk pregnancies go to 40 weeks and beyond quite often.  First time mothers are especially likely,.

What about the risks of going past 42 weeks?  Isn’t there a risk to the baby?

According to Wagner, a study from 1963 found that a slight increase in the number of stillbirths after 42 weeks, with a significant increase after 43 weeks.  This study has been frequently cited as evidence to support induction before 42 weeks.  But Wagner puts the risk to the individual woman into perspective —  as it turns out, only 3 percent of pregnancies even extend beyond 42 weeks, and even after 43 weeks, only 10 percent (of that 3%) have any problems.  So as you can probably deduce, the chances of going so far past your due date that you put your baby at risk is pretty insignificant (about 0.3%).  You have a much greater chance of going into labor spontaneously before you reach 43 weeks, and an even if you don’t, there’s a good chance your baby will still be born healthy.

Another risk in induction due to postdates is the inaccuracy of EDDs (Estimated Due Dates).  Because of normal variations in the menstrual cycle length amongst average women, and the tendency to base due date on the last menstrual period (LMP), a woman’s due date could be off by 2 weeks or more.  So if a woman gets induced at 40 weeks, her baby could actually only be 38 weeks (or less), which is associated with more health problems for the baby.  This is a phenomenon called iatrogenic prematurity (essentially, doctor-caused prematurity), and is a growing portion of the increasing prematurity rates.

So, post-dates is generally NOT a medically indicated reason to be induced.

“Big Babies” or Fetal Macrosomia

First, macrosomia is defined as a baby weighing over 8 lbs 13 oz.  It legitimately effects about 10% of all pregnancies in America.

Perhaps the one of the most prominent concerns about big babies is a complication called “shoulder dystocia,” where the baby’s shoulders get stuck on the mother’s pelvic bone.  The risks of this complication include paralysis, Erb’s palsy, and fetal hypoxia (baby doesn’t get enough oxygen). Sounds scary, doesn’t it?  And if you are of the unfortunate 1% of women who experience it, it will definitely be treated as scary in the typical US hospital.

So what happens when a woman experiences shoulder dystocia?  Just think ALARMER.

  • Ask for help. This involves requesting the help of an obstetrician, anesthesia and pediatrics for subsequent resuscitation of the infant.
  • Leg hyperflexion (McRoberts’ maneuver)
  • Anterior shoulder disimpaction (suprapubic pressure)
  • Rubin maneuver
  • Manual delivery of posterior arm
  • Episiotomy (Does anybody else wonder how cutting open the perineum has any impact on a baby who is stuck on the pelvic bone?  Okay good, me either.)
  • Roll over on all fours

According to Wikipedia, the advantage to this mnemonic is that it goes from least invasive to most invasive.  That sounded all fine and good, until I got to the last method — roll over on all fours.  Wait, what??  How is rolling over on all fours less invasive than say, an episiotomy (you know, where they cut your perineum)?

Turns out “Roll over on all fours” has a name — Gaskin’s maneuver, and was discovered by midwife Ina May Gaskin (yes, the same one mentioned earlier).  This maneuver opens the pelvis (wider than lying on her back) , allowing the shoulders to slide through. Sounds pretty non-invasive.  In one study, the Gaskin maneuver had the following results:

“Half of the eighty-two babies weighed more than 4000 grams (about 8.5 pounds); 17 or 21 percent weighed more than 4500 grams (about 8 pounds, 10 ounces); thirty of the 1-minute Apgar scores were less than or equal to 6, and two were less than or equal to 3; only one of the 5-minute Apgar scores was less than or equal to 6, which is 1.2 percent; forty-nine of the women or 60 percent delivered over an intact perineum, and there were no third- or fourth-degree lacerations; one woman had postpartum hemorrhage not requiring transfusion; and one infant had a fractured humerus.

That sounds a heck of a lot better than an episiotomy to me.  So why aren’t more hospitals using this technique?  Probably the biggest reason is that movement during labor is limited by current birth practices, such as epidurals and electronic fetal monitoring, which generally require the mother to lay on her back.

Another issue with justifying induction because of macrosomia is the accuracy of the diagnosis.  Macrosomia is generally diagnosed using an ultrasound, which has been found to be inaccurate in nearly two-thirds of cases.

And according to Wagner, while macrosomia has been used to justify induction, evidence does not support this practice.  In fact, C-Section rates increase with induction due to macrosomia, with NO improvement in outcomes.  As he puts it in Born in the USA, “trying to hammer out too large a baby can harm the baby.”

Conclusion:

  • Evidence suggests that induction rates of less around 10% are essential to optimal outcomes for mothers and babies.
  • About 50% of pregnant women experience induction in the US.
  • Gestational ages range, and 42+ weeks pregnancies can still be healthy and deliver spontaneously.
  • Due dates can be up to 2 weeks off.
  • Big babies have a higher risk (1%) of developing “shoulder dystocia,” which has serious complications.
  • Diagnoses of macrosomia can be inaccurate up to two-thirds of the time.
  • If you induce due to macrosomia, you have a greater risk of undergoing a C-section

Oh, and:

  • Episiotomies widen your vagina (skin/muscle), not your pelvis (bone).  Just say “no” to episiotomy.
  • Patience is key.

With all that I’ve read, I have to say I come down on the side of “very wary” of induction.  Unless you are in the 10% whose medical condition requires it (see above), it’s probably better for you to wait until your baby is good and ready to come out.

Here are some more natural ideas for inducing labor:

  • Walk.  A lot.  — I walked more in the last month of my pregnancy than I did in the previous 8 months combined.  Which was nice, since I couldn’t walk farther than 4 feet without pain for about a week after she was born.
  • Have sex.  A lot. — As awkward as it sounds, the prostaglandins in semen help soften the cervix.  And it might sound a little dirty, but let’s admit it, that’s how we all got into this predicament to start with.
  • Start a lengthy project.  — Not only does this fill your time, but you are almost guaranteed that your baby will come before you can finish it.
  • Buy expensive concert tickets for right around your due date.  — Along the same vein, it’s likely that you won’t get a chance to use them.

HAPPY WAITING!