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So what about VBAC after more than 2 cesareans? Is that a reasonable choice? This is more difficult to say because there is so little data available on VBA3+C. Women HAVE had VBACs after 3 or more cesareans, but most documentation of this comes from anecdotal birth stories on the internet and in the lay VBAC literature like Silent Knife, Natural Childbirth After Cesarean, The Vaginal Birth After Cesarean Experience, etc. (See VBA2C Stories for exact references.) Unfortunately, although many women have had VBACs after 3 or more cesareans, documentations of this in the medical literature are harder to find. Although the sample sizes are generally extremely small, some cases can be gleaned from the VBAC literature. The following are some of the studies that report on a trial of labor in women with 3 or more previous cesareans.
Some studies did have passing mention of women with 3 or more previous cesareans in their research group, but did not specify outcome for them separately (i.e., Granovsky 1994). Therefore, their stats could not be figured into the totals here. The only studies listed here specify at least partially the outcome of the group with 3 or more previous cesareans. Also, studies before 1979 were omitted because the laboring conditions and protocols were so different then that comparisons are difficult. Too many of those studies involve women with classical cesareans (which have a higher rupture rate), heavy use of drugs, forceps, and other highly interventive protocols which obscure the risk.
The following studies did specify trials of labor with women with 3 or more previous cesareans, and did document at least partially their outcomes:
Saldana 1979 - Notes 38 TOLs in women with 2+ cesareans, and 22 had VBACs for a rate of 58%. Of the 22 VBACs, the authors note that 4 were VBA3Cs. There were 0 ruptures or dehiscences in the TOL group.
Martin 1983 - Notes 19 TOLs in women with 2+ cesareans, including 6 trials of labor in women with >2 cesareans. 3/6 had a VBA3+C (50% VBA3C rate). There were no ruptures or dehiscences in any of the multiple cesarean mothers who had a TOL; one was found in a woman in the ERCS group.
Tahilramaney 1984 - This study showed an increased rate of dehiscences with an increasing number of uterine incisions, but the difference did not reach statistical significance. There was a rate of 2.6% after 1 c/s, 3.0% after 2 c/s, and 7.5% after 3 cesareans. However, again, these did not reach statistical significance, nor did it appear that these dehiscences were clinically relevant (i.e. true ruptures) although more information is needed to know for sure. Distinctions between dehiscences and ruptures were not clearly made at all; the summary reads as though there were 5 ruptures out of 836 total patients in the study; most of these appear to be in the elective repeat cesarean arm of the study and if they appeared in any of the multiple c/s patients, it was not specified. So the exact status of rupture rates in multiple cesarean mothers cannot be determined, but the authors do conclude at the end that "the number of previous C/Ss...appear to have little, if any, prognostic significance for uterine rupture."
Farmakides 1987 - There were 57 TOLs in women with 2 or more cesareans. 39 of these were in women were 2 previous cesareans, and 18 were in women with 3 previous cesareans. Of the 57 in the total group, 77% had a VBA2+C, but there's no way to tell what the VBAC rate was in the 3 previous c/s group. However, there was only one dehiscence and no ruptures at all in the overall TOL group, which means that there were no ruptures in the 3 cesarean group. It is unknown how many previous cesareans the woman with the dehiscence had.
Stovall 1987 - There were 6 VBA3Cs in women with low transverse scars in this study (plus 1 in a woman with 3 low vertical scars) for a 100% VBA3C rate. There were no ruptures in the multiple previous c/s TOL group.
Phelan 1987 - There were 1796 women who underwent a trial of labor in this study; 10 of them had had 3 previous cesareans. 9/10 had a VBA3C for a success rate of 90%. The overall rupture rate was 0.3% for all TOLs, and the authors did not specify the rupture rate by amount of previous cesareans. However, they did state that ruptures were not increased in the group with multiple previous cesareans.
Pruett 1988 - 55 TOL after 2+C; 51 after 2 c/s and 4 after 3 c/s. 2/4 women with 3 previous cesareans had a VBAC, for a success rate of 50%. One of them did have a scar dehiscence, but she was in her 7th pregnancy (grand multips are known to be more at-risk for rupture) and the type of incisions she had were unknown. She had had erratic prenatal care, and pitocin was also used in her labor. Baby was born vaginally and was fine; the scar dehiscence was only noted afterwards with manual exploration after bleeding. She choose to have a hysterectomy anyhow for sterilization. Because the mother was a grand multip and had also had oxytocin for her labor, this dehiscence cannot be said reliably to have been due to 3 previous scars, but neither can it (or a combination of the 3 factors) be ruled out.
Flamm 1988 - As part of a much larger study, 89 women had a TOL after 2 previous c/s. Of these, 7 women had a TOL after 3 previous cesareans. 5 had a VBAC (71% VBA3C). None had any ruptures.
Veridiano 1989 - Although the concentration was mostly on VBA1C, this study did document successful VBACs in women with multiple previous cesareans---14 VBA2Cs, 4 VBA3Cs, 2 VBA4Cs, and 1 VBA5C. Success rates were not given for each category separately; the overall VBAC rate for all VBA2+Cs was 84%. Authors state there were 'no complications' for the multiple cesarean TOL group, so presumably there were no ruptures or dehiscences in this group.
Novas 1989 - 36 TOLs in women with 2+ c/s, including 9 TOLs in women with 3 or more previous c/s. 8/9 had a VBA3+C for a success rate of 89%. This compared to a success rate of 78% for VBA2C. There were no ruptures in any of the multiple cesareans group.
Hansell 1990 - 35 TOLs in women with 2+ c/s, including 6 TOLs in women with more than 2 c/s. 5 women with 3 previous c/s had a TOL; 3/5 or 60% had a VBA3C. 1 woman with 4 previous c/s had a TOL, she had a VBA4C (success rate of 100%). In the TOL group, there were 2 asymptomatic windows or 'thinning' of scars with no complications or problems; there were NO ruptures in the TOL group (the elective repeat cesarean group had a rupture before term).
Cowan 1994 - 75 TOLs in women with 2+ c/s, including 3 TOLs in women with 3 prior c/s. All three women had a VBAC, for a 100% VBA3C rate. There were no ruptures in the 3 c/s group.
Miller 1994 - The largest study of VBA2+C rates around. There were 1827 TOLs in women with more than one previous c/s, including 1586 in women with 2 previous c/s and 241 in women with 3 or more previous c/s. These offer some substantial study sizes to evaluate. In this the rupture rate (1.7%) does appear to go up as uterine incisions go up when averaged; when separated out, the rupture rate was 1.8% for VBA2C and 1.2% for VBA3+C, so it does not continue to go up as the number of previous c/s got higher, which weakens the conclusion that it must be due to the number of previous incisions. That rate is double that of the 0.6% rate for VBA1C; the overall averaged rate is ~3x higher. However, no attempt was made to control for oxytocin use; if more VBA2+C moms were induced or heavily augmented, that could explain a higher rate of rupture for them. This is a major weakness in the study. The authors do conclude lukewarmly that offering a TOL to women with 2 or more previous cesareans is a 'reasonable option' but that it is best kept only for 'motivated' patients. They also emphasize the decreased VBAC success rate among those with multiple cesareans, but this is greatly overstated, given that 75% still achieved VBA2Cs (79% of those with 3 or more c/s!), a rate higher than many VBA1C studies.
Table VII: Miller, 1994 "Vaginal Birth After Cesarean: A 10-Year Experience"
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# of previous c/s
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number of TOL
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VBAC success rate
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rupture rate
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VBA1C
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n = 10, 880
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83%
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0.6%
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VBA2C
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n = 1586
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75%
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1.8%
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VBA3+C
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n = 241
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79%
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1.2%
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|
VBA2+C (averaged)
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n = 1827 total
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75% averaged
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1.7% averaged
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Summary of VBA3+C Studies
Of all of the studies listed above, there were 239 VBA3+Cs. Unfortunately, only a few studies specify the exact VBAC success rate among those with 3 previous cesareans. Of these, most had excellent success rates, although in all but one of the studies the numbers were quite small, which limits the power of the conclusions that can be drawn. The success rates follow.
Table VIII: VBA3+C Success Rates
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Study/Year
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VBA3+C Success Rates
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VBACs/TOLs
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Martin, 1983
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50% VBA3+C
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n=3/6
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Stovall, 1987
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100% VBA3+C
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n=7/7
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Phelan 1987
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90% VBA3+C
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n=9/10
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|
Pruett, 1988
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50% VBA3+C
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n=2/4
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Flamm, 1988
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71% VBA3+C
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n=5/7
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Novas, 1989
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89% VBA3+C
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n=8/9
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Hansell, 1990
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67% VBA3+C
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n=4/6
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Cowan, 1994
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100% VBA3C
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n=3/3
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Miller 1994
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79% VBA3+C
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n=190/241
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If you add up the numbers of all the VBA3C studies for which we have specific success rate data, there was a total of 231 out of 293 VBA3+Cs. That averages out to a total VBA3+C success rate of 79%, which is pretty darn good! In fact, that is a higher rate of success than many VBA1C studies and even much VBA2C data.
This good success rate probably reflects that women who go for a VBAC after this many cesareans are probably carefully selected by their providers, carefully select their providers, are probably highly motivated, and probably prepare very carefully, four things which might well lead to a higher success rate. It's possible that the numbers could be skewed because they are so small, but even so, a 79% success rate is excellent.
Some women are still told that VBAC after 3 or more cesareans is impossible, that the rupture rate would be too high, or that there is NO data on this situation and therefore it would be too risky to try. It is simply not true that VBA3+C is impossible; it has been documented at least 231 times, and the number is certainly higher since other studies mention VBACs with 3+ previous cesareans but don't stratify results more specifically to enable us to add them to the success rate totals.
It's also notable that the rupture rate in most of these VBA2+C studies was 0.0%, although this is probably partly because of the small sample sizes. In the studies for which we have uterine rupture rates specified in VBA3C TOLs, there were 4 ruptures out of 312 TOLs, for a rupture rate of 1.3%, about the same as the VBA2C rate. (Do note that not all studies specified both success rates and rupture rates for VBA3+C, so numbers are a little different than in the table above). As with VBA2C, it is important to note that this rate reflects the rupture rate when pitocin and other drugs are used quite liberally, and it is impossible to know for sure what the true underlying rupture rate would be without pitocin or other drugs (or very minimal use of them).
Most of the VBA3+C ruptures are from the Miller 1994 study, which does show a higher rate of ruptures (BUT did not control for oxytocin use, which may have increased the rate). A definitive evaluation of the VBA3+C possible risk cannot be done at this point, because the numbers are too small. Although multiple previous cesareans may increase the rupture rate some, it does not appear so far to do so excessively, and is certainly a risk that a mother and her provider might assume with suitable precautions and duly informed consent.
In recent prior practice bulletins on VBAC, ACOG did not rule out a trial of labor after more than 2 prior cesareans. However, in the July 1999 practice bulletin on VBAC, the organization takes a step back. It lists as candidates for a trial of labor women who have had "one or two prior low transverse cesarean deliveries." Citing the Miller 1994 study, it states that "Women who have had two previous low-transverse cesarean deliveries also may be considered for a trial of labor, but the risk of uterine rupture increases with the number of previous uterine incisions," and women should be warned accordingly.
On the other hand, in the section on contraindications for VBAC, women with 3 or more cesareans are not specifically forbidden from a TOL either. ACOG basically hedges its bets by endorsing offering a TOL for women with one prior cesarean, 'allowing' a TOL for women with two prior cesareans (with the proper warnings to the woman), and not taking a specific stand for or against a TOL in women with more than 2 prior cesareans. As noted previously, it states that, "There has been a tendency to expand the list of obstetric circumstances under which VBAC may be appropriate. These include multiple previous cesarean deliveries...Whether trial of labor should be encouraged for patients with these obstetric circumstances...is controversial. Although success has been reported in some series, continuing analysis of the risk of adverse outcome is necessary before VBAC is routinely adopted in these circumstances."
Although data is limited on this issue and some providers still block VBA3Cs by citing lack of data on which to gauge possible risk, there certainly IS some data on this situation. However, the numbers are less than definitive because most major institutions have not 'permitted' trials of labor in women with multiple cesareans, or limited most study to those women with only 2 previous cesareans. Obviously, the only way to GET more data is to study the situation (with informed consent) instead of ignoring it or just declaring it impossible. As long as major research centers refuse to study the issue seriously, definitive data (with enough women studied to give the data sufficient power to be conclusive) will be limited. But that should not prevent strongly motivated women with supportive providers from trying VBA3+C, as long as there is adequate informed consent. Many providers do believe that there IS a place for VBA3+C on a smaller-scale, fully informed basis, although it generally has its strongest support among midwives.
Although the numbers are generally small, VBA3+C has occurred. It is documented in anecdotal and lay VBAC literature, and it is also documented in the medical literature. In fact, there are documented instances in the medical literature not only of VBA3Cs, but also of VBA4Cs, and even a VBA5C. In the lay literature, there are anecdotal accounts of VBA6C as well.
Chances are very good---more than 3 of 4--that VBA3+C will succeed, and the risk of rupture, although perhaps slightly higher than after 1 cesarean, is still lower than many other possible emergency complications in birth. VBAC after more than 2 previous cesareans should not be automatically eliminated from consideration, provided the mother is strongly motivated, well informed of the possible risks, and she and her provider know how to maximize her chances of success and minimize the risks. Many providers DO support VBAC after two OR MORE cesareans as a 'reasonable option' for the most motivated women.
Considering the possibility of uterine rupture can be very scary, and the emphasis on this rare but potentially catastrophic complication tends to frighten many women out of a trial of labor. What doctors 'forget' to mention is that elective cesarean doesn't eliminate the possibility of uterine rupture either, and that elective cesareans carry their own set of significant risks to you and to baby as well. Neither elective repeat cesarean nor a trial of labor are without potential risks.
Uterine Rupture
Many women don't realize that choosing an elective repeat cesarean does NOT eliminate your chances for uterine rupture. Doctors often make it sound like rupture only happens during a TOL, and that by choosing an ERCS, you can eliminate even a small chance of a rupture occurring. Although most studies focus on uterine rupture during TOL, uterine ruptures can and do occur before labor in pregnancy, tend to be more devastating, may result in hysterectomy, and babies have died from it. It is NOT true that deciding against a VBAC means that you won't have any risk of uterine rupture. In fact, occasional studies have even found a higher rate of rupture in the ERCS group! So keep in mind that it is the PREVIOUS CESAREAN that puts you at risk for uterine rupture.
How does rupture risk compare between the two birth modes? It depends on the study you look at. In Rosen's 1991 meta-analysis of morbidity and mortality associated with cesareans, a trial of labor was NOT associated with an increased rate of uterine rupture OR fetal death. However, in Mozurkewich and Hutton's 2000 comparative meta-analysis of data between 1989-1999, a trial of labor was associated with a slightly increased rate of ruptures and therefore fetal death, although the absolute risk still remained small (0.4% rupture, 0.2% fetal death for TOL group; 0.2% rupture and 0.1% fetal death for ERCS group).
So why did the 1991 study find NO increase in risk for rupture or fetal death with a TOL, yet the 2000 study did? This may reflect the increased rate of uterine rupture some studies have found in the 90s (perhaps due to drug overuse), or it may reflect other factors such as methods used in the analysis. Although it's unclear at this point, deciding on a trial of labor may increase the risk of rupture slightly overall (especially today with the high rates of induction and drug use), but not by a great deal. The absolute risk is generally low, and some ruptures and deaths would happen regardless. ERCS does not prevent ruptures or fetal death completely, as some doctors imply. And it's not clear whether a TOL really raises the risks of rupture or not, even slightly; some studies seem to support a slight increase in risk, and other studies do not.
It is not logical to 'forbid' a trial of labor simply because of the vague possibility of uterine rupture. Women with prior cesareans can rupture at any time during pregnancy, not just in labor. Doctors do not insist that a woman who has had a cesarean spend her entire pregnancy in the hospital just in case she might rupture, or that she forego another pregnancy entirely, simply because she is at increased risk of rupture. The risk of rupture is real in either group, but statistically small. Keep the risks in perspective.
Remember also the risk of uterine rupture compared to other complications. Although some doctors like to use scare tactics, the relative risks of true rupture compare with other uncommon but possible risks of labor. Dr. Bruce Flamm lists these various risks in his book, Birth After Cesarean: The Medical Facts. He lists the chances of placental abruption (premature detachment of the placenta) at about 1%, of placenta previa (placenta blocking the birth canal) at 0.5%, of fetal distress in labor at 1-5%, of prolapsed umbilical cord at about 1%.
According to his figures, average risk of uterine rupture after 1 previous cesarean (<1%) is LESS than risks of other possible complications; the average risk of rupture after 2 or more previous cesareans is apparently only slightly more than any one of these conditions (and about the same as the chances for fetal distress). If a doctor does not 'forbid' a trial of labor to non-cesarean moms based on fears of placenta previa, placental abruption, cord prolapse, or fetal distress, why should he 'forbid' a trial of labor to prior cesarean moms based on fears of rupture?
Maternal Risks of Repeat Cesareans
Furthermore, don't forget that elective repeat cesarean operations also carry risks, both to the mother and the baby. Although modern operative techniques and conditions have made a c/s a much safer operation these days, it still is MAJOR surgery and carries small but very real risks. And the risks tend to increase with every repeat operation. Unfortunately, the risks of repeat cesareans are rarely mentioned when doctors discuss the risks and benefits of a trial of labor with a mother, and so-called 'VBAC consent forms' rarely make equal mention of the potential risks of cesareans. Most often women are advised of the potential risks of VBAC without equal emphasis on the potential risks of cesareans, which are quite real too.
For example, blood loss is about twice as great in cesarean birth, and may increase with each successive operation. Scarring and adhesions may occur and cause long-term pain, numbness, or other problems; the more cesareans you have, the longer and harder the surgery is because of scarring and possible adhesions. Some women experience numbness, tingling, burning, or pain near their incision site for years after a c/s. Infection rates are also much higher after a c/s (especially in larger mothers), there can be respiratory problems from anesthesia, decreased bowel function after surgery, or problems with blood clots that can even cause death. Although very rare, paralysis from spinal/epidural anesthesia can occur as well, and the risk of the mother dying during a cesarean is about 2-4x greater than during vaginal birth.
The risks of a c/s don't just end in immediate morbidity problems. In Washington
There is also some evidence that women who have cesareans also have a higher rate of other health problems such as appendicitis and gall bladder problems (Lydon-Rochelle, 2000). On the surface, this may seem strange, but people who have abdominal surgeries do tend to experience higher rates of problems like gall bladder troubles, and infection is a risk factor for appendicitis. Surprisingly, few people thought to associate these problems with cesareans, which shows how lightly our society treats cesarean surgery compared to other surgery. So although the chances are not high, repeated cesareans may raise your risk for gallbladder disease or other problems.
Even if your recovery from ERCS is uneventful, it is still more difficult than recovery from normal vaginal birth. Physical recovery generally takes longer, and a number of c/s moms experience significant problems with post-partum depression or even post-traumatic stress disorder. While most women cope okay with c/s recovery, it's not the easiest way to begin parenting, especially if you have older children who also need your attention. VBAC activists point out that if you were adopting a baby instead, you probably wouldn't choose to have major surgery on the day you were to receive custody of the baby. You could probably manage if the two did coincide, but it's certainly not the most stress-free way to begin. Cesareans are not just stressful physically and emotionally, but they can also stress early parenting and family life. In terms of maternal risks, ERCS clearly present substantial potential problems.
Fetal Risks of Repeat Cesareans
ERCS can also present risks to the baby, including a higher rate of breathing problems (Respiratory Distress Syndrome) and problems due to prematurity. Labor helps prepare the baby to get ready to breathe in the outside world, and babies born by cesarean have a much higher rate of breathing problems and RDS, which can be very serious. In addition, many OBs schedule ERCS for 38 weeks, and if there is any question on due dates or if the mother's cycles run long, this can cause the baby to be born too soon (iatrogenic prematurity), with the accompanying risks of jaundice, breathing problems, hypoglycemia, difficulty nursing, etc. Hook (1997) found that 9% of babies born by ERCS were actually younger than the desired 38 weeks, so this is a significant risk.
The baby can also be injured during the cesarean; some babies are cut accidentally during the uterine incision and may have a scar. Furthermore, babies born by elective c/s sometimes have trouble breastfeeding, their mothers may have delayed initiation of lactation because of the lack of labor hormones to jumpstart lactation, and excessive blood loss during cesarean can cause anemia, an underdiagnosed cause of poor milk supply for many women. Although cesareans are lifesaving operations in certain cases (which we can be truly thankful for when necessary), cesareans are NOT the way that nature designed babies to be born. The abrupt transition to life outside the womb without the benefits of labor hormones and the physical process of birth IS a less optimal beginning. Although this can usually be compensated for, it does have risks.
Risks to Future Pregnancies
In addition, if you plan future pregnancies, repeat cesareans can really take a toll. This is a VERY important fact that is rarely mentioned by OBs; the health of your next baby may be impacted by the birth mode you choose this time. Every time a scar is inflicted upon the uterus, the risk of problems in subsequent pregnancies increases. For example, Hemminki (1996) found that although the risk was fairly small, women with prior cesareans had "reduced fertility", including more ectopic pregnancies and more miscarriages. In addition, there was 2-4x the risk for placental abruption (separation of the placenta from the uterus prematurely, which can kill the baby) in women with prior cesarean. The worst-case scenario of fetal death from uterine rupture is often emphasized when considering VBAC, but placental abruption often is also fatal to babies. Although both abruptions and ruptures are usually detected in time to save the baby, both have catastrophic potential consequences and must be taken very seriously. Doctors should not be glossing over abruption risks from repeat cesareans.
The risk for other placental problems following a cesarean are substantial, and increase as the number of cesareans increases. For example, placenta previa (low-lying placenta that fully or partially blocks the uterus, with strong risk of hemorrhage and possibly death for mother and/or baby) is almost universally acknowledged to be MUCH more common in women with prior cesareans. Hemminki found a 4-5x risk for placenta previa in women whose first pregnancy ended in cesarean. And the risk apparently increases with the number of prior cesareans. Hendricks (1999) found a 2.2x risk for previa after one c/s, a 4.1x risk for previa after two c/s, and a 22.4x risk after 3 c/s. Ananth (1997) found a 4.5x risk for previa after one c/s, a 7.4x risk after two c/s, a 6.5x risk after three c/s, and a 44.9x risk after four or more c/s.
Although these are very indicative of a problem, risk ratios can be somewhat misleading in terms of knowing absolute risk. To compare risks more easily, it's helpful to know what percentage of women with prior cesareans actually get placenta previa, compared to the incidence in the overall population. Ananth (1997) found that the average incidence of placenta previa in the overall population until 1985 was 0.36%, but that after 1985 it increased to 0.48%, a substantial increase when talking about large populations and multiple studies. They theorize that this increase probably has to do with the increased cesarean rate as well as an increased rate of detection from ultrasounds. Chattopadhyay (1993) found a previa rate of 0.44% in women without prior cesareans, versus a 2.54% previa rate for those with prior cesareans, a 5-fold increase. Zaideh (1998) found a previa rate of 0.25% in women without prior cesareans, versus a 1.87% previa rate in women with prior cesareans. The rate of previa was 1.78% after one c/s, 2.4% after two c/s, and 2.8% after three or more c/s. So when you consider the rate of uterine rupture after 2 or more cesareans (probably between 1-2% with liberal pitocin use), you also have to consider that having another cesarean would also raise the risks for placenta previa in any future pregnancies (to somewhere around 2-3%), possibly placing your life or your baby's life at risk next time.
In addition, placenta previa is sometimes accompanies by a potentially catastrophic condition called 'placenta accreta' (or percreta). In this, the placenta actually grows through the uterine wall (and sometimes even into the structures around it, like the bladder) and cannot detach after the birth. This often results in hysterectomy for the mother, and sometimes even in her death. In fact, several VBAC studies analyzed for this FAQ noted occasional maternal deaths due to placenta accreta, including the 1993 Chattopadhyay study mentioned above. Asakura 1995 noted several hysterectomies due to placenta accreta, and found hysterectomy to be 11.3x more likely in women with more than one prior cesarean. Mozerkewich and Hutton's 2000 meta-analysis found that women in the TOL group had 0.39x the risk for hysterectomy as the women in the ERCS group; this is probably because of the increased rate of accreta found in women with cesarean after cesarean. Thus, although hysterectomy is a risk for both the TOL and the ERCS group, the risk is probably greater in the ERCS group, probably mostly in the group with multiple cesareans.
Although placenta accreta can occur without prior cesarean, it is much more common with prior cesareans. For example, Zaideh (1998) found accreta associated with previa in 9% of cases without prior c/s, versus 40.8% of cases with prior c/s. Similarly, Chattopadhyay (1993) found accreta with previa in only 4.5% of the cases without prior cesareans, versus 38.2% of cases with prior cesareans. Chattopadhyay further analyzed accreta by the number of prior cesareans; after one c/s, previa was accompanied by accreta in 10% of cases, but after two or more c/s, previa was accompanied by accreta in 59.2% of cases. And about 2/3 of women who had placenta previa accreta after a c/s required a hysterectomy.
Risks from a 'Failed' Trial of Labor
To be fair, one complicating factor to a TOL is that there may be a higher rate of infection and other problems if you have a 'failed' TOL. It's true that the 'failed' TOL group sometimes has more infections or operative injuries etc. than ERCS group. Some doctors have seized upon potential increased morbidity among the 'failed' TOL group as a reason to discourage women from a TOL (while conveniently forgetting to mention all the risks from ERCS). Although the 'failed' TOL group may have slightly increased morbidity rates, these are usually minor and not difficult to resolve, and are generally limited to a small percentage of the group. It's not appropriate to urge surgery simply because a small percentage of women who have a cesarean after a TOL may get infections, some of which may be avoidable by better intrapartum care procedures.
Of course, the worst-case scenario is uterine rupture, and this may be more common in the TOL group than the ERCS group. However, the question is by how much (studies differ, and not all show a higher risk with TOL), and how many of these ruptures could be avoided by greater caution with induction, avoiding use of multiple labor drugs, and avoiding aggressive early pitocin augmentation. It may be that with greater caution in labor protocols, the risk between groups might be more equal. But it's also important to note that while fetal death has occurred with uterine rupture, the majority of cases do not have long-term harm. Most ruptures of low-transverse scars, if caught and acted upon quickly, do not result in fetal death or injury, and usually do not result in maternal hysterectomy either. The risk of permanent harm does exist and must be taken seriously, but most cases do end up resolving without significant harm. (And of course, there can be significant harm from ERCS as well.)
Keep in mind that women and their babies who do have a VBAC do MUCH better on the whole (less infection, less blood loss, less morbidity) than those having an ERCS, and your chances of VBAC with a decent provider are about 70%. Because the chances for VBAC are so good, the TOL group (successful or not) tends to have better outcomes statistically than the ERCS group on the whole, as long as the VBAC success rates are high. If VBAC success rates are lower, then the potential morbidity from the 'failed' TOL group may reduce or completely wipe out the statistical advantages the TOL group usually has. The moral of this is probably the importance of finding a provider with very high VBAC rates, and beliefs and policies that actively promote VBAC! In other words, if you are going to choose a TOL, choose only a provider that whole-heartedly supports VBAC, uses policies that minimize potential morbidity, and has a very high rate of VBACs. If you choose a provider that is more interventive (insists on early induction for VBAC, for example), or has a low rate of VBAC success, your chances for 'failed' TOL and potential associated morbidity increase.
Potential morbidity in a 'failed' TOL can be probably be minimized by reducing the number of vaginal exams and internal procedures done during labor, perhaps using antibiotic prophylaxis during TOL cesarean if rupture of membranes has occurred previously, and by concentrating on improving wound care. Instead of promoting surgery to avoid potential morbidity from a 'failed' TOL, providers might do better to emphasize ways to prevent avoidable ruptures, ways to improve outcome should rupture occur, and ways to minimize infections and other 'minor' morbidity that may occur in a small but definite percentage of those whose TOLs end in cesarean.
Summary
While there are some potentially very serious consequences from a TOL, risks are relatively small and usually not catastrophic unless problems are not acted upon quickly. Similarly, there are also potentially serious consequences from ERCS as well, although these tend to get de-emphasized in VBAC studies and counseling by doctors. Neither TOL nor ERCS completely erase the risk of uterine rupture; the risk is probably slightly higher in a TOL (especially when pitocin etc. is used) but the risk is still reasonable, compares to the risks associated with multiple ERCS, and must be weighed against the better outcomes associated with VBACs.
The benefits of VBAC are quite significant to both mother and baby, and these factors alone make a TOL sensible for those who desire it. Statistically, the greatest chance for optimizing outcomes is to be in the TOL group because of the high rate of VBAC success that occurs. And if you do plan on more pregnancies, a TOL makes more sense since each successive cesarean places you and your future babies at more risk for serious placental problems. However, as always, the specifics of each case have to be considered separately, and each woman has to consider what's right for her. Statistically, the overall chances for better outcome are with the TOL group, but it's certainly possible that in some cases, ERCS is the more beneficial choice. Each case has to be decided on an individual basis.
Finally, as always, it's important to keep all these numbers in perspective. Chances are very good (about 97-98%) that even if you choose an ERCS, your next pregnancy probably won't have placenta previa. Similarly, chances are very good (about 98-99%) that if you choose a TOL, you probably won't have a uterine rupture. But while it's important to remember that neither ERCS nor TOL is totally risk-free, the absolute rate of complications with either an ERCS or a TOL is pretty low, and chances are you won't have significant problems either way you choose.
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