Public Service Post: The Bishop Score

The Choosing Wisely campaign was begun in order to reduce unnecessary use of medicine and medical procedures.  Non-medically indicated use is unsafe for patients as well as being expensive.  Not only are there costs involved in the medicine or procedure itself, but there are also costs in treating side effects and other health consequences.

The American College of Obstetricians and Gynecologists (ACOG) has a list they made for the Choosing Wisely campaign, “Five Things Physicians and Patients Should Question.”  The top two items on the list are about elective induction of labor (these two items also made the American Academy of Family Physicians list).  The first warns against scheduling a delivery (cesarean or induction) before 39 weeks unless there is a clear medical indication.  Here is the text of the second:

Don’t schedule elective, non-medically indicated inductions of labor between 39 weeks 0 days and 41 weeks 0 days unless the cervix is deemed favorable:  Ideally, labor should start on its own initiative whenever possible. Higher Cesarean delivery rates result from inductions of labor when the cervix is unfavorable. Health care practitioners should discuss the risks and benefits with their patients before considering inductions of labor without medical indications.

This is similar to the information I provided in my posts on Pitocin and elective inductions.  Before 41 weeks, unless there is a clear medical indication, labor should begin on its own.  Note the caveat that if an elective induction is to occur, the cervix should be “favorable.”  A laywoman might ask what this means.  A favorable cervix is soft, effaced and dilated.  But really the standard that physicians use for determining whether a woman’s body is ready to labor is the Bishop score.

In 1955, Dr. Edward Bishop published a paper (subscription needed to get text) on elective induction of labor in which he looked at the likelihood of induction success based on several factors: fetal position, cervical softness, cervical effacement, cervical dilation, and the “station” of the fetus (how far it was engaged in the woman’s pelvis).  We might question the ethics of inducing labor without medical indication, but Dr. Bishop did find that if the baby was anterior and the cervix was soft,  higher levels of effacement, dilation and engagement made elective inductions likely to work and labors were more likely to be shorter.  This chart from Preparing for Birth sums it up:

Bishop’s scoring system is still used and has some accuracy at predicting the likelihood of an induction’s success.  Some doctors use a simplified score that just looks at effacement, dilation, and station.

Here are some graphs from Intermountain Healthcare’s care process model on elective induction:

You can see that higher Bishop scores lead to higher likelihood of a successful induction, and that the higher the score, the shorter the labor.

Nulliparous women (first time mothers) are especially likely to have cesareans when they have lower Bishop scores.  It is important to note, however, that even with a favorable Bishop score, nulliparous women are much more likely to have a cesarean than they would be if labor began on its own, and they are more likely to have operative deliveries (forceps or vacuum).

Dr. Gene Declercq of Boston University and colleagues run a wonderful site call Birth by the Numbers and produced this chart with data from Listening to Mothers III:

This data does not imply that an induction cannot be successful, that no one should have an epidural, or that a cesarean might not be necessary for reasons having nothing to do with inductions or epidurals.  But the data do give credence to the idea of choosing wisely.  Taking Pitocin to start labor in an uncomplicated pregnancy before 41 weeks is akin to taking high blood pressure medicine when your blood pressure is normal (credit Debra Bingham).  The Bishop score may help to determine if the medicine will not hurt you, but why take it in the first place?  If you do want to go the induction route, however, your Bishop score is a tool to let you know how likely an elective induction is to lead to unnecessary major surgery.

All inductions should be done with full informed consent and should not be scheduled around a care provider’s office hours, vacation time, or child’s birthday party.  The well being of the pregnant woman and her fetus and the woman’s informed choice should be the only considerations.  A woman is a human being and not a vessel to be manipulated for the convenience of others.

Avoid an Unnecesarean

It would be hard to find anyone who doesn’t think the cesarean rate is too high.  The World Health Organization says that a 15% rate “is not a target to be achieved but rather a threshold not to be exceeded.”  Healthy People 2020 goals (see section MICH-7) target reductions in primary cesareans and increases in vaginal birth after cesarean (VBAC) as two primary goals in maternity care. In some situations, the benefits of a cesarean far outweigh the risks, but when the surgery is not needed, it has the small but significant potential to cause severe complications for the woman and her baby, and also affects the woman’s subsequent pregnancies.

Cesareans have many advantages for doctors.  The payment for attending a cesarean is equal to or greater than attending a vaginal birth.  While even a fast vaginal birth generally takes at least several hours from the time the woman arrives at the hospital,  performing a cesarean takes about an hour.  Cesareans are not risk-free, but the outcomes are predictable.  And scheduling a cesarean is particularly lucrative and convenient for doctors because they can avoid conflicts with office hours and family/leisure time.

Dr. Jonathan Weinstein of Frisco Women’s Health, whose cesarean rate is under 15%, offers the helpful list, Top Ten Signs Your Doctor is Planning to Perform an Unnecessary Cesarean Section on You:

1. Arrives to L&D immediately after office hours and says, “I just don’t think this baby is going to fit”
2. Third Trimester, Routine Office Visit, “I think this is going to be a big baby you should just have a C/S” – Did you know? ACOG has very specific guidelines for when it is appropriate to offer a patient an elective C/S for MACROSOMIA (fancy word for large baby). ‘Prophylactic (elective) cesarean delivery may be considered for suspected fetal macrosomia with estimated fetal weights greater than 5,000 gms (11 pounds) in women without diabetes and greater than 4,500 gms (9.9 pounds) in women with diabetes.
3. “We should induce at 39 weeks your baby is getting too big” – Did you know? According to ACOG, ‘Induction of labor at least doubles the risk of cesarean delivery without reducing shoulder dystocia (rare situation where baby’s shoulder can get stuck at delivery) or newborn morbidity(complications). Suspected fetal macrosomia is not an indication for induction of labor, because induction does not improve maternal or fetal outcomes.’
4. Performs routine ultrasounds at end of pregnancy to see how big your baby is. Did you know? Ultrasounds at the end of the pregnancy can be 1-2 pounds off. Ask some VBAC patients who were talked into a C/S for this, then had a vaginal delivery of a bigger baby the next time.
5. “You have a positive herpes titer (or history of herpes); the baby will get it if you deliver vaginally.” Try some Valtrex for the last month of the pregnancy that is pretty much standard of care now. It prevents outbreaks and allows for a normal vaginal delivery.
6. “Your baby is breech you need to have a C/S” Ever heard of or performed an External Cephalic Version? It really does work.
7. “You have pushed for 2 hours” (with an epidural that prevents you from feeling anything so you are probably not pushing effectively; this is evident on exam because the baby’s head is still perfectly round, but you do not need to know that) it’s just not going to come out.”
8. “I scheduled you for an induction at 39 weeks, it is just soooo… much more convenient for you!” (and so much higher risk of ending in a C/S, especially if you are not dilated when you start the induction). At least 80% of my VBAC patients were induced the previous pregnancy. For whose convenience was the induction?
9. First Visit (7 weeks), “Congratulations you are having twins. I will go ahead and schedule your C/S at 38 weeks, but don’t worry if you go in to labor early I will cut you right away!” Translation, “I am scared out of my mind for you to deliver your babies vaginally because I am not trained on what to do when the second baby is coming, plus it pays more to cut you open. Oh yeah, I don’t have that great a rapport with you because I only spend 2 minutes (fundal height, heart beat and ‘I’ll see you next time’) with you each visit, so I am afraid I will be sued for trying to do the right thing.” (note from Human with Uterus: planned cesarean for twins is not evidence based.)
10. First Pelvic Exam in Office (7 weeks), “Hmm, your pelvis is pretty narrow”
11. Bonus Tip: 38-week visit, “Your blood pressure is a little up today you are probably developing preeclampsia or toxemia. That can cause you to have a SEIZURE! The treatment is to deliver the baby. You need a Cesarean Section this is the quickest way to resolve it. Let’s get you up to L&D NOW!” Translation – Preeclampsia or Pregnancy Induced High Blood Pressure is a pain in the butt. If I induce you, it could take 24 hours or more and then I would have to manage your blood pressure, and put you on Magnesium. This is way too inconvenient. Do not worry you can try to have the baby vaginally next time. Yeah right!

For more information on cesarean/induction for “big baby,” see this post from Evidence Based Birth.

Despite reports that cesareans are performed at maternal request, only about 1% of primary cesareans were requested by the woman.  As a woman cannot perform a cesarean on herself, the skyrocketing rate must be driven by providers.  Providers also say that high cesarean rates are driven by liability concerns. A connection between liability environments and cesarean rates exists, but the effects are small.  A natural experiment in Texas, which underwent tort reform, showed that reductions in liability did not lead to corresponding changes in cesarean rates–cesarean rates went up at roughly the same rate as they did in the rest of the country.  Texas cesarean rates are currently 35.3%, higher than the national average.

We might also generally question the ethics of performing a surgery that is in the best interest of the doctor, not the woman and her child.  When a doctor recommends a risky procedure such as major abdominal surgery, women should always ask for references to evidence (meaning documents they can read, not off-the-cuff statistics).  A woman’s care should be a process of shared decision making, not following someone else’s orders.  A woman’s humanity demands nothing less.

Elective Inductions: Be Thankful not to Have One

I have written previously about problems with Pitocin overuse (and about widespread overuse of other medical procedures in birth).  Now that the holidays are almost upon us, it seems wise to revisit the Pitocin issue.

Pitocin is a synthetic form of oxytocin, a natural hormone that promotes bonding and also causes cervical dilation and labor contractions.  Using Pitocin interferes with the body’s natural output of oxytocin, doesn’t effectively dilate the cervix, and prevents the body’s release of endorphins that naturally alleviate pain.  There are sometimes good reasons for inducing labor with Pitocin (for instance, if the baby must be born right away for health reasons).  In many cases, however, good reasons are not in the equation when the Pitocin comes out.

In 1990, fewer than 10% of women underwent labor induction.  Now, estimates indicate that up to 40% or more of labors may be induced.  As scheduled cesarean rates have also gone up dramatically in that same period (see this graph), we know that the proportion of women planning a vaginal birth who are induced has gone up even more.  If you doubt that large numbers of births are being scheduled, see this graph that shows that births are disproportionately on Tuesday-Friday, with an extraordinary dip on weekends.

Doctors like to indicate that elective inductions are primarily done at maternal request.  While some women definitely do request inductions, pregnant women cannot induce themselves with Pitocin.  Doctors seem to have no problem enforcing non-evidence-based practices that women don’t want, such as not eating in labor, but act as if they are helpless in the face of induction requests.

Some doctors also have selective memory when it comes to their own induction practices.  According to mothers, childbirth educators, and nurses, it is usually doctors who are encouraging inductions.  As one childbirth educator said,

[A]n increasing number [of women] are being encouraged by their physicians to have labor induced. Threats of “your baby is getting too big” or “your blood pressure is a bit high” or “going past your due date is dangerous” and seduction with “your baby is ready, let’s get on with it” are almost routine.

Even some doctors acknowledge that elective induction is often physician driven.  Dr. Vivien von Gruenigen writes,

Health care providers may request a patient to have an elective induction of labor and the “fee for service” model is a factor.  This routine is common for physicians in solo practice with needed time off call or impending vacation.  In addition, many physicians in group practice schedule elective inductions when they are on call for the purpose of financial gain.

Inductions are usually performed without true informed consent.  Pitocin is not FDA approved for elective induction of labor and carries a black box warning because it is a high alert medication (prone to errors in administration that lead to catastrophic consequences).  It appears that very few women are told that they are receiving a high alert medication that is being used “off label.”

One suggested consent form for elective induction includes the following for women to acknowledge:

• An increased risk of the need for cesarean section (surgical abdominal birth)
• I have also discussed the use of cervical “ripening agents” with my physician and I understand their separate risks of: a. Excessive stimulation of the uterus to the point that my fetus may become compromised and require emergency delivery, either vaginally or abdominally. b. I also understand that rarely the uterus may rupture under these circumstances, and cause death of my fetus and severe hemorrhage or death to myself.
• An increased risk that instruments may be used to accomplish a vaginal delivery if necessary.
• I also realize that if I have a cesarean birth, I am likely to require cesarean births for all of the children I may have in the future, and that each of these will incur the usual risks associated with cesarean section that I might have avoided had I had this birth vaginally.
•  I acknowledge that there may be an increased risk for the need of blood transfusion, and I give my full consent to receive blood and blood products as necessary unless specifically stated here:

I have never met a lay woman who was aware of all of these risks, even if she had undergone an elective induction.

Marilyn Curl notes that elective deliveries spike before holidays–but that women do not always realize that the induction is elective:

Few doctors want to be pacing the halls on Thanksgiving or Christmas, waiting for a mother to deliver, so it’s not uncommon to see a surge of women with normal pregnancies being told that there might be an issue and that they should consider scheduling the delivery, coincidentally, right before a holiday.

Jill Arnold has a whole post about the pre-holiday induction phenomenon at The Unnecesarean.

Aside from  the health risks, there are many other disadvantages to a pre-holiday induction, namely that there are so many of them being done that the obstetric wards are likely to be overcrowded.  Robin Elise Weiss notes that

• Trying to schedule an induction just before Christmas ensures a hugely busy and overworked staff because of everyone else doing the same thing.  I’ve personally seen women laboring in the halls or having very long wait for services like epidural anesthesia because of it.
• When you have a baby in the week before Christmas (with lots of other women), you’ve also got a crowded postpartum floor.  This means longer waits for being seen by pediatricians, getting pain medicationss, etc.
• Being in the hospital in a crowded induction season can mean that you have to share resources in the hospitals that are already spread thin, like the lactation consultant, breast pumps, birth certificate clerks, etc.

At a recent PCORI conference, consensus opinion was that elective induction of labor before 41 weeks was one of the most important issues facing perinatal care today.  As Deborah Bingham pointed out, we don’t give people with normal blood pressure medication for high blood pressure, because that would be dangerous; similarly, we should not be giving healthy pregnant women medication designed for rushing a birth in a medically dangerous situation.  And it certainly shouldn’t be done by tricking women into thinking an induction is necessary because of a big baby or other concern that is not an indication for induction.

Not even before Thanksgiving or Christmas.

Update: you may also want to read Public Service Post: The Bishop Score