Cesarean Delivery

December 14, 2007

Why C-sections are done

An excellent second choice in how to have a baby...The thing that you have to know about C-sections is that when it comes to having a baby, it's second choice. Vaginal delivery is the natural way for which we were designed. There is a way out, and a normal vaginal delivery makes use of that route. However...

There are times when it is prudent to resort to second choice. Obstetrics is very easy at a certain point, that point being delivery. The reason for this is that while expecting a vaginal delivery, time and the laws of physics will allow it to happen...or not. Things become pretty obvious when there's a problem with the expected progress.

A Dr. Friedman years ago described the expected progress of two variables over time: dilation of the cervix and descent of the baby. Today we know it as the Friedman's Curve. When there is a slow-down of the slope of these curves, then the labor is called dysfunctional. There are two general types of dysfunction: The cervix can stop dilating, or the baby's head will descend no farther. Or both. It is generally felt that when there is a plateau of Friedman's curve (stopping of progress) of two hours while in active labor, or of three hours in active labor with an epidural, then "failure to progress" is the diagnosis and C-section is indicated.

Of course, appraisal of the "3 Ps" must be made to see if there's a correctable measure. Simple things such as changing the expectant mother's position repeatedly can use gravity to guide a baby into a less obstructed descent through her pelvis.  Gentle rotation of a baby's head by a vaginal exam, when the hang-up is near enough to the vaginal opening to allow this, may re-establish a course such that the natural flexion of the baby's neck can pivot him or her back on the original course.  Appraisal of the effectiveness of the contractions can be made accurately by measuring the actual pressure withing the uterus during labor. Such measurement involves wires, tubes, and similar attachments which will interfere with a mother's natural movement (she can't go walking the halls), but this is a welcome trade-off if it's important to her that she avoid an avoidable C-section.

But when the facts of "failure to progress" are irrefutable and unchangeable, then there may begin danger in forcing a baby's head against the mother's bones any longer. This may be seen as the vaguely termed "fetal distress." The fetal heart tones may go down with each contraction ("decelerations") or drop sharply and recover just as quickly ("variable decelerations").  This distress is for the most part a reflex and not dangerous; however, it can progress to true fetal compromise and will eventually show signs of metabolic malfunction (fetal acidosis). In the academic world of debatable significance of this type of distress or that type of distress, fetal acidosis is the one bad thing everyone can agree upon is dangerous to the unborn baby. The window of opportunity between these two manisfestations of "fetal distress," the reflex and the eventual acidosis, is different for each pregnancy, baby, and labor, but generally it's considerably long enough to effect delivery by second choice (C-section) before things get very scary.

Another development of allowing labor to progress with obvious jamming up is the significant molding of the fetal skull that can take place. Molding is the play between the skull plates that aren't fused together in the baby.  The space between these plates is most famously demonstrated by the "soft spot" of the baby's head.  In fact, all of the spaces between the skull bones are soft spots, and this slack allows the bones to shift around much like the tectonic plates of continents shift during earthquakes. (Labor likened to an earthquake?  I suppose there are worse metaphors, right?) The result of prolonged molding is a misshapen head, which after delivery again uses the unfused skull bones to reverse this change within a few days. So molding isn't dangerous. But when a C-section delivers a baby whose head is shaped just like the inside of his or her Mom's pelvis, the decision for C-section was not a bad decision.

True, you can get a misshapen head with vaginal delivery, too, the molding changing the shape of the head with the descent through the pelvis. This is a good thing, for a rigid sphere with no "play" would have doomed our species from the very beginning. This play of the molding allows for on-going adjustments of the geometry to allow for passage through the maternal pelvis. Since it can be just as pronounced as that seen with a failure-to-progress, C-section baby, molding itself isn't something you can use all by itself to indicate the need for C-section. It's a natural safeguard and, I reemphasize again, isn't dangerous. Even the harsh medical slang, "banana-head" baby, will sport a beautifully round globe of a head that any parent will gloat over--but the gloating may take a week.

The dreaded C-section rate

What should the C-section rate be for a doctor? Well, if you need one, 100%. If you don't, 0%.

I'm not trying to be coy; in other words, each patient experience is unique and must be taken case-by-case. Each labor is unique and cannot be judged by some homogenized "evidence-based" medicine statistic which, sadly, is what's used as a basis for information in most of the self-help pregnancy books around.  (Not mine, of course.). In other words, the art of medicine will take evidence-based medicine as a guideline and temper it with judgement.  This means that the decision to do a C-section for you and your doctor may not be sqeaky clean from the academic criteria of what's best for a unit population of 100,000 women-births, but it may be what's best for your own baby. If you have a problem with your baby, you're on your own thereafter, not getting any help from those 100,000 women cited in evidence-based medicine.  And the insurance companines, which use evidence based medicine, don't care about the rest of your baby's life, because they figure you'll be with some other insurer soon anyway.

Evidence-based medicine is not a conspiracy of bad ethics. It's how medicine improves and progresses.  But it's up to your doctor to inject a dose of judgement into your individualized care.

See the Point-Counterpoint on C-section rates below.

Indications for C-section

There are many reasons for doing a C-section:

  • Herpes infection could expose the baby to serious illness, and since this virus can be caught by exposure of the baby to the virus in your birth canal, C-section will theoretically (not guaranteed) avoid exposure.
  • A previous C-section with a vertical scar on the uterus (womb) may pose a danger of uterine rupture with a labor.  This type of incision is considered to heal more weakly. The other type of incision, a transverse (horizontal)) incision, heals with greater strength and could make you a candidate for a VBAC (Vaginal Birth After Cesarean) delivery with a subsequent pregnancy (see below).
  • Breech delivery is another problem addressed by C-section. The only allowable vaginal delivery with a breech (any non-head-first--"vertex"--position) is the frank breech, when both legs are flexed straight up (not bent at the knees), such that the buttocks will make an effective dilating "wedge" and the ankle won't jam against the exit (as when the knees are flexed).  The frank breech criteria for vaginal delivery also have to include a baby judged to be smaller than previous babies that were known to negotiate the pelvis before. In other words, you're not going to want to take a chance on a breech baby that is a mother's first, since she has no "proven pelvis" for any size baby yet.  On the other hand, if her biggest baby was, say, 9 pounds, and the frank breech baby is estimated to be only 7 pounds, it can be considered.  Since estimates are fraught with error, many obstetricians feel safest doing C-sections for all breech babies.  This is especially true for those doctors who feel that breech babies, even those meeting all of the vaginal delivery criteria, have an increased chance of "soft" neruological signs, like ADD, hyperactivity, and ADHD.
  • Twins in which one of the babies is breech is the same problem. Although some obstetricians think all twins should be delivered by C-section, since the waiting time for twin #2 to descend could increase the risk of prolapsed cord; and the "soft" neurological signs argument applies here as well.
  • Failure to progress, defined as lack of descent of the baby's head or lack of dilation of your cervix for two hours in active labor, or for three hours in active labor with an epidural.  Failure to progress without real, acitve labor, is not failure to progress.  Real, active labor is generally considered to be at least 3 sufficient contractions over every 10 minutes.
  • Fetal distress obligates an obstetrician to C-section if a vaginal delivery is not imminent. The standard of care is such that a hospital is expected to put together a C-section within 30 minutes, so if vaginal delivery can happen before that, it just might beat out the C-section approach.  Some hospitals can effect C-section in less than 30 minutes, especially those that have 24-hour in-house anesthesia.  This is something to be considered in choosing a place for birth of your baby.
  • Serious bleeding from an abnormally placed or separating placenta elevates C-section to a heroic, life-saving procedure.
  • Maternal disease which may put the mother in danger with labor, e.g., heart disease, can make operative delivery a necessary choice as well.
  • Maternal choice C-section--wherein an expectant couple choose to have an electively scheduled C-section instead of the normal labor and vaginal delivery. Reasons may include timing an exact birth day for help coming in from out of town, a previously unpleasant vaginal delivery experience, a previous severe vaginal tear that took forever to heal, or even personal whim. Lately, studies have implied that the chances of later urinary or fecal incontinence are greater in women who have passed a baby through their birth canal, indicating C-section may be wise now that everyone's living into their 70s and 80s and even beyond.  This is still controversial, but there's enough evidence to make this an important consideration.  Recently, the American College of Obstetricians and Gynecologists (ACOG), sent out a technical bulletin (an official pronouncement) that maternal choice C-section is not unethical, making it a completely legitimate option.  Many people feel that if a woman has a right to terminate her pregnancy, she should also have a right to decide how her baby should be born.

C-Section Rates Will Be Lower

One of the hottest issues in Obstetrics today is the high C- Section rate. Percentages anywhere from 17% to 35% are quoted as the likelihood that an expectant mother may have this route of delivery for her child. Many factors have contributed to this in the United States. Certainly a doctor's legal fears of a bad outcome have made the rates higher. But doctors often misdirect their distrust of lawyers. Upon closer examination, practicing good medicine is really the same thing as practicing defensive medicine, because not having a reason to be legitimately sued means a good outcome, and this is always in the baby's and parents' best interests. What seems like professions at odds is really nothing more than everyone being on the same side. In a way.  Of course, I'm only talking about claims of merit, and reputable attorneys understand this and object to frivolous lawsuits. But while wanting good outcomes has driven the C-Section rate up, there are many factors that can drive it down.

Many women can be offered vaginal birth after Cesarean (or, VBAC), which would lower the repeat-C-Section rate, since the adage, "Once a C- Section, always a C-Section," is no more valid than an old wive's tale. One of the biggest contributors to the overall C-section rate is the population of women with previous C-sections going on to have all their babies that way. VBAC is designed to impact this repeat phenomenon.

Of course, the way to prevent "previous" C-sections of tomorrow is to avoid first C-sections today. Delays in administering epidurals until labor is well established will allow the baby's head to descend into the birth canal at the correct angle, preventing the labor from being "hung up" and make less likely a C-Section for failure of the labor to progress. The field of Anesthsiology has countered the delay in this valuable form of pain relief by developing something called a "walking epidural." This can be given before 5 centimeters dilatation without tripling the risk of ultimate C-section like the standard epidural does if given that early.

Elective inductions, while useful and often indicated, should be carried out with certain guidelines. If the mouth of the womb (cervix) is not inducible, the labor may be unduly drawn out. A C-Section may become necessary, when waiting for a more inducible cervix may have made a vaginal delivery more likely. Of course, some medical complications make induction mandatory before its time, but these are situations that can't be helped (rupture of membranes, for instance).

One of the leading causes of C-sections is the notorious "failure to progress," defined as lack of cervical dilation or descent of the baby's head for two hours (three hours with an epidural). Some physicians are stretching these definitions of ineffective labor. Even when progress stalls, sometimes a gut feeling will allow a doctor to let the labor go on for some time after, as long as the baby's heart rate is excellent. Even the most sluggish progress can sometimes surprise everyone with a vaginal delivery, but such conservatism requires extreme caution and watchfulness for fetal distress.  Certainly a doctor who wants to avoid the stigma of having too high a C-section rate shouldn't put any individual baby at risk for statistics' sake.

C-Section Rates Will Be Higher

It used to be that one out of every 200 women who had a C-section died. With the advances in maternal-fetal medicine, antibiotics, fetal surveillance, and hospital care, this statistic has been erased to the point wherein the dreaded C-secion of yore has now been exonerated as nothing more than a second choice in ways to have a baby.  Also, recovery from surgery--all types of abdominal surgery--is not the ordeal it use to be.  Potent anti-inflammatories given IV before surgery, continuous epidurals into the recovery period--not just for labor anymore--can mask the pain significantly for days until a patient is "over the hump."  The latest generations of antibiotics have done much to eliminate the dangers that contributed to the mortality rate of the past.

Generally, it's much safer than it's ever been, even to the point where in most patients the risk difference between vaginal delivery and Cesarean are almost negligible. (I speak, though, of patients cared for in private practice.  In the training hospitals which get an unwieldy share of the indigent, those without proper prenatal care, those with poor nutrition, and those with high risk behaviors, the complication rate can sometimes match those of yesteryear, since little or no prenatal care isn't any different from the prenatal care offered when the statistics used to be much worse.)

Now that we've beaten out evolution and are living way beyond what we were designed for, new evidence suggests age-related weaknesses like urinary and fecal incontinence can be avoided by not challenging the supportive tissues with passage of a baby. Sphincters need support, and those supports are weakened by that freight train known as vaginal delivery.  When no one lived past 40, things like incontinence wasn't a big deal, eclipsed by the big deal of more than likely being dead by the time such conditions were to develop.  But now that we have malls, no one wants to have an accident in front of T. J. Max.  The jury's still out on a definitive verdict of whether the initial blame on vaginal delivery is correct, but until such time as that's rendered, these conditions may be so distasteful to a woman as to prompt her to be more safe than sorry.  This decision becomes more alluring now that the "more safe" is really becoming safer than every before.

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