External Cephalic Version after Prior Cesarean - 2018 study

People whose babies are breech and have a history of a prior cesarean are often told that External Cephalic Version (ECV), manually encouraging the baby to turn head-down, is simply not a choice for them. The fear is that manipulation done during an ECV might make the uterus rupture along the scar from the prior cesarean.

We have discussed ECV after a Prior Cesarean extensively before. The results of all the studies so far suggest that ECV after prior CS is not unduly risky and can avoid many unnecessary repeat cesareans. ECV should be offered to women at term with a breech presentation, regardless of prior cesarean status. Unfortunately, ECV is woefully underutilized. One study from New Zealand estimated that only 26% of eligible patients with breech presentations were referred for ECV.

2018 Study

Recently, a new study (Impey 2018) was published that looks again at the question of ECV after prior cesarean (CS). Its results were both encouraging and disappointing.

In this new U.K. study, researchers looked back retrospectively over a 16 year period and found 100 cases where babies of women with a prior cesarean presented breech at term, were offered, and consented to a ECV.

Basically, the study found about a 50% rate of success in turning the baby head-down. Those who had head-down babies afterwards had a trial of labor after cesarean (TOLAC), and 68% had a VBAC.

The authors did a literature search on ECV after prior CS and found no increased rate of uterine rupture after ECV. That agrees with the literature search we did.

However, the authors chose to dilute this good news by pointing out that while ECV avoided some cesareans, only 30 women out of the 100 original group had a VBAC. In other words, while they found the practice safe, the way they word the abstract made it sound like instituting a practice of ECV after prior cesarean is not worth pursuing because it is only marginally successful.

This flies in the face of previous research. The big question is why their ECV success rate was so low. Only 50% of their ECV tries worked to turn the baby head-down. That reduced their candidates for TOLAC by half, and then only about 2/3 of these women had a VBAC. That's why the final numbers were low.

If you look at comparable studies, Weill 2016 had a 74% ECV success rate, while Burgos 2014 had a 67% ECV success rate. Why were their results so much better? That's what the UK study authors should be asking themselves. Seems like they need training on how to do ECV more successfully.

Summary

The good news from the study is that External Cephalic Version after a prior cesarean is safe. There are potential risks inherent to the procedure, of course, but these risks do not appear to be any greater in women with prior cesarean than in those without a prior cesarean. And of course, the alternative of an automatic repeat cesarean with a breech carries its own potential risks that also must be considered. The choice should be up to the mother.

The bad news from the study is how few women with prior cesareans are being offered ECV and how low the ECV success rate was. It took 16 years in the study to find a data pool of 100 women who had a prior cesarean and a breech presentation at term who were offered an external version and who accepted it. ECV is tremendously underused, especially in those with a prior cesarean. And a ECV success rate of only 50% is pitiful. Better training is obviously needed.

External Cephalic Version at term can avoid many unnecessary cesareans, yet it is woefully underused in many institutions. It is a reasonable choice that needs to be expanded, especially in women with prior cesareans. Furthermore, training to achieve greater ECV success rates in more places needs to occur.



References

Eur J Obstet Gynecol Reprod Biol. 2018 Dec;231:210-213. doi: 10.1016/j.ejogrb.2018.10.036. Epub 2018 Oct 22. External cephalic version after previous cesarean section: A cohort study of 100 consecutive attempts. Impey ORE, Greenwood CEL, Impey LWM. PMID: 30412904

OBJECTIVE: External cephalic version is commonly not performed in women with a previous cesarean section. Fear of uterine rupture and cesarean section in labor are prominent. The risks, however, of these are unclear. This study aims to document the safety and efficacy of external cephalic version in women with a prior cesarean section in a series of 100 consecutive attempts, and to perform a literature of the existing literature. STUDY DESIGN: This is a retrospective cohort study of prospectively collected data of external cephalic version attempts in women at term with a previous cesarean section, and a literature review of previously published series. External cephalic version was performed by one of 3 experienced operators, with salbutamol tocolysis if appropriate, using ultrasound to visualize the fetal heart and place of fetal parts. RESULTS: 100 women with a prior cesarean section underwent external cephalic version over a 16-year period in one institution. 68% had no previous vaginal delivery. The external cephalic version success rate was 50%, and 30 (63.8%) of these subsequently delivered vaginally. There were no cases of uterine rupture or other complications. A literature review of series containing a total of 549 cases revealed no cases of uterine rupture or perinatal death. CONCLUSIONS: External cephalic version in women with a prior cesarean section is safe but enables a vaginal birth in only about a third of women.

Aust N Z J Obstet Gynaecol. 2016 Sep 14. doi: 10.1111/ajo.12527. [Epub ahead of print] The efficacy and safety of external cephalic version after a previous caesarean delivery. Weill Y, Pollack RN. PMID: 27624629

BACKGROUND: External cephalic version (ECV) in the presence of a uterine scar is still considered a relative contraindication despite encouraging studies of the efficacy and safety of this procedure. We present our experience with this patient population, which is the largest cohort published to date. AIMS: To evaluate the efficacy and safety of ECV in the setting of a prior caesarean delivery. MATERIALS AND METHODS: A total of 158 patients with a fetus presenting as breech, who had an unscarred uterus, had an ECV performed. Similarly, 158 patients with a fetus presenting as breech, and who had undergone a prior caesarean delivery also underwent an ECV. Outcomes were compared. RESULTS: ECV was successfully performed in 136/158 (86.1%) patients in the control group. Of these patients, 6/136 (4.4%) delivered by caesarean delivery. In the study group, 117/158 (74.1%) patients had a successful ECV performed. Of these patients, 12/117 (10.3%) delivered by caesarean delivery. There were no significant complications in either of the groups. CONCLUSIONS: ECV may be successfully performed in patients with a previous caesarean delivery. It is associated with a high success rate, and is not associated with an increase in complications.

BJOG. 2014 Jan;121(2):230-5; discussion 235. doi: 10.1111/1471-0528.12487. Epub 2013 Nov 19. Is external cephalic version at term contraindicated in previous caesarean section? A prospective comparative cohort study. Burgos J, Cobos P, Rodríguez L, Osuna C, Centeno MM, Martínez-Astorquiza T, Fernández-Llebrez L. PMID: 24245964

OBJECTIVE: To determine if external cephalic version (ECV) can be performed with safety and efficacy in women with previous caesarean section. DESIGN: Prospective comparative cohort study. SETTING: Cruces University Hospital (Spain). POPULATION: Single pregnancy with breech presentation at term. METHODS: We compared 70 ECV performed in women with previous caesarean section with 387 ECV performed in multiparous women (March 2002 to June 2012). MAIN OUTCOME MEASURES: Success rate, complications of the ECV and caesarean section rate. RESULTS: The success rate of ECV in women after previous caesarean section was 67.1% versus 66.1% in multiparous women (P = 0.87). The logistic regression analysis confirmed this result (odds ratio 0.93, 95% CI 0.52-1.68; P = 0.82) adjusted by the variables associated with success of ECV. There were no complications in the previous caesarean section cohort. The vaginal delivery rate in the previous caesarean section cohort was 52.8% versus 74.9% in the multiparous cohort (P < 0.01). There were no cases of uterine rupture. CONCLUSION: Based on our data, we conclude that complications are uncommon with ECV in women with previous caesarean section, with a success rate comparable to that of multiparous women. Uterine scar should not be considered a contraindication and ECV should be offered to women with previous caesarean section with breech presentation at term.

Click here for older references on ECV after CS.

External Version for Breech After Prior Cesarean

An External Cephalic Version (ECV, or turning the baby manually to a head-down position) is one option open to people whose babies are breech. However, if you have had a prior cesarean, you may be told that this is not an option for you.

The evidence does not support excluding those with a prior cesarean from an External Cephalic Version. It's time for obstetric societies to update their guidelines about this, and it's time for more providers to routinely offer ECV.

Background

The main benefit of External Cephalic Version is that it is often successful in getting the baby head-down, and a head-down birth is usually less risky than a breech birth.

Although many breech babies can be born vaginally just fine (especially those that meet certain criteria and/or are attended with alternate positioning), there are some increased risks to be aware of.

As a result, many care providers these days strongly prefer a cesarean or even schedule one automatically with a breech baby. Because some areas do not "allow" Vaginal Birth After Cesarean (VBAC), this can mean that all future babies must also be born by cesarean.

Therefore, getting the baby head-down via an External Cephalic Version can help prevent not just the first cesarean, but many automatic repeat cesareans and the serious complications that can happen with them.

Of course, like everything, ECV has both benefits and risks. The risks of ECV include premature labor, placental abruption (placenta detaching too early), hemorrhage, or fetal distress. Although real, these risks are relatively rare, usually less than 1%.

Obviously, sometimes ECV is also contraindicated. Most clinicians agree that ECV should not be attempted in the presence of pre-existing fetal distress, placenta previa, placental abruption, premature rupture of membranes, and certain uterine malformations. Low amniotic fluid levels may also be a relative contraindication.

A good review of the benefits and risks of ECV can be found here. Basically, ECV is able to turn babies head-down most of the time without many complications, and thus prevents many cesareans that would otherwise happen. This is important because cesarean rates are so high; ECV is quite an effective way to reduce the number of cesareans and probably many cases of resulting abnormal placental attachment.

Astonishingly, though, research shows that ECV is not used that much in many areas, despite its relative success rate and potential for lowering the cesarean rate.

Often, doctors don't even tell people that ECV is an option. They just schedule a cesarean and discourage people from exploring other options. One study from New Zealand estimated that only 26% of eligible patients with breech presentations were referred for ECV.

The situation is even worse if you have had a prior cesarean. For those with a scarred uterus, it's even harder to get an ECV because doctors have been taught that it's too dangerous.

The Controversy

People whose babies are breech and have a history of a prior cesarean are often told that ECV is simply not a choice for them because manipulation done during an ECV might make the uterus rupture along the scar from the prior cesarean.

The problem is that there is no actual proof that this is a substantial risk. No study has found this to be a problem, but just the mere fear of the possibility has led to its denial for this group. Currently, you can still find recommendations online that list prior cesarean (or any prior uterine surgery) as a contraindication to even attempting an ECV.

However, a policy of no External Cephalic Version for people with a prior cesarean is not supported by research.

There are a number of studies, including some very recent studies, that suggest that people with a prior cesarean SHOULD have the option to have an External Version if they want it.

The latest study (Weill 2016) had 158 women in the study group and found no increase in complications in the group with a prior cesarean. The success rate of ECV in this group was good (117/158, or 74%), and only 12 of these patients ended up with a cesarean during labor. That means that using ECV in the prior cesarean group prevented 105 automatic repeat cesareans. The authors summarized their findings this way:

ECV may be successfully performed in patients with a previous caesarean delivery. It is associated with a high success rate, and is not associated with an increase in complications.

Similarly, another recent study (Burgos 2014) found no increased rate of complications in the group with a prior cesarean. The authors concluded:

Uterine scar should not be considered a contraindication and ECV should be offered to women with previous caesarean section with breech presentation at term.

Another study (Abenhaim 2009) also found no increase in complications in those with a prior cesarean who had an ECV. The authors stated:

Concern about procedural success in women with a previous cesarean section is unwarranted and should not deter attempting an external cephalic version.

However, both RCOG (Royal College of Obstetricians and Gynaecologists) and ACOG (American College of Obstetricians and Gynecologists) still hesitate to endorse ECV after prior cesarean. They say that there is not enough research to prove that it is safe. They point out that many of the studies on ECV and prior cesarean are fairly small, which limits their power.

That is a fair point. It's true that most studies have been relatively small and we don't have a huge pool of data to pull from, but taken together the results are quite encouraging.

One older review (Sela 2008) did a search of previous studies to pool the results. They found a total of 124 patients who had an ECV after prior cesarean. They added 42 patients from their own database. Adding in the 36 from the Abenhaim 2009 study, 70 from the Burgos 2014 study, and 158 from the Weill 2016 study, you get a total of 430 patients who have been documented to have an ECV after prior cesarean ─ all without any poor outcomes.

What this means is that there isn't ANY evidence to prove that ECV is unsafe in those with a prior cesarean. While the data pool is still somewhat limited, so far ALL of it supports ECV after prior cesarean.

Yet ACOG's recently revised 2016 guideline on ECV states, "Having had a previous cesarean delivery is not linked with lower rate of success; however, whether it magnifies risk for uterine rupture is not known." They cite only two studies from 1991 and 1998 and state, "Larger studies would be needed to establish the risk of uterine rupture." This ignores all the recent studies on ECV. This cavalier omission will continue to lead many care providers to continue to deny ECV to those with prior cesareans.

Although more research is needed, the bottom line is that the accumulating evidence certainly suggests that an ECV after a prior cesarean is not unduly risky and is a reasonable choice that should be offered to those who want it. 

A more reasonable view of the evidence has led the SOGC (the Canadian version of RCOG and ACOG) to state:

External cephalic version is not contraindicated in women with a previous Caesarean birth.

It's time for ACOG and RCOG to recognize that they are basing their guidelines more on fear than on the latest evidence and update their guidelines accordingly. Bravo to the Canadians for leading the way on this issue.

More research should be done ─ an excellent question is WHY hasn't more been done by now? My best guess is that it reflects the exaggerated fears of the care providers rather than a reasoned response. But given the absence of poor outcomes up till now, research on this topic should be expanded and in the meantime, ECV should be available to those with a prior cesarean.

In addition, it is time for more care providers to offer ECV as an option across the board. This is a sadly underused procedure that could certainly greatly impact cesarean rates and maternal morbidity, both by preventing the first cesarean and lowering the rate of automatic repeat cesareans that follow.


References

External Cephalic Version After Prior Cesarean

Aust N Z J Obstet Gynaecol. 2016 Sep 14. doi: 10.1111/ajo.12527. [Epub ahead of print] The efficacy and safety of external cephalic version after a previous caesarean delivery. Weill Y, Pollack RN. PMID: 27624629

BACKGROUND: External cephalic version (ECV) in the presence of a uterine scar is still considered a relative contraindication despite encouraging studies of the efficacy and safety of this procedure. We present our experience with this patient population, which is the largest cohort published to date. AIMS: To evaluate the efficacy and safety of ECV in the setting of a prior caesarean delivery. MATERIALS AND METHODS: A total of 158 patients with a fetus presenting as breech, who had an unscarred uterus, had an ECV performed. Similarly, 158 patients with a fetus presenting as breech, and who had undergone a prior caesarean delivery also underwent an ECV. Outcomes were compared. RESULTS: ECV was successfully performed in 136/158 (86.1%) patients in the control group. Of these patients, 6/136 (4.4%) delivered by caesarean delivery. In the study group, 117/158 (74.1%) patients had a successful ECV performed. Of these patients, 12/117 (10.3%) delivered by caesarean delivery. There were no significant complications in either of the groups. CONCLUSIONS: ECV may be successfully performed in patients with a previous caesarean delivery. It is associated with a high success rate, and is not associated with an increase in complications.

BJOG. 2014 Jan;121(2):230-5; discussion 235. doi: 10.1111/1471-0528.12487. Epub 2013 Nov 19. Is external cephalic version at term contraindicated in previous caesarean section? A prospective comparative cohort study. Burgos J, Cobos P, Rodríguez L, Osuna C, Centeno MM, Martínez-Astorquiza T, Fernández-Llebrez L. PMID: 24245964

OBJECTIVE: To determine if external cephalic version (ECV) can be performed with safety and efficacy in women with previous caesarean section. DESIGN: Prospective comparative cohort study. SETTING: Cruces University Hospital (Spain). POPULATION: Single pregnancy with breech presentation at term. METHODS: We compared 70 ECV performed in women with previous caesarean section with 387 ECV performed in multiparous women (March 2002 to June 2012). MAIN OUTCOME MEASURES: Success rate, complications of the ECV and caesarean section rate. RESULTS: The success rate of ECV in women after previous caesarean section was 67.1% versus 66.1% in multiparous women (P = 0.87). The logistic regression analysis confirmed this result (odds ratio 0.93, 95% CI 0.52-1.68; P = 0.82) adjusted by the variables associated with success of ECV. There were no complications in the previous caesarean section cohort. The vaginal delivery rate in the previous caesarean section cohort was 52.8% versus 74.9% in the multiparous cohort (P < 0.01). There were no cases of uterine rupture. CONCLUSION: Based on our data, we conclude that complications are uncommon with ECV in women with previous caesarean section, with a success rate comparable to that of multiparous women. Uterine scar should not be considered a contraindication and ECV should be offered to women with previous caesarean section with breech presentation at term.

J Perinat Med. 2009;37(2):156-60. doi: 10.1515/JPM.2009.006. External cephalic version among women with a previous cesarean delivery: report on 36 cases and review of the literature. Abenhaim HA1, Varin J, Boucher M. PMID: 19021458

AIMS: Whether or not women with a previous cesarean section should be considered for an external cephalic version remains unclear. In our study, we sought to examine the relationship between a history of previous cesarean section and outcomes of external cephalic version for pregnancies at 36 completed weeks of gestation or more. METHODS: Data on obstetrical history and on external cephalic version outcomes was obtained from the C.H.U. Sainte-Justine External Cephalic Version Database. Baseline clinical characteristics were compared among women with and without a history of previous cesarean section. We used logistic regression analysis to evaluate the effect of previous cesarean section on success of external cephalic version while adjusting for parity, maternal body mass index, gestational age, estimated fetal weight, and amniotic fluid index. RESULTS: Over a 15-year period, 1425 external cephalic versions were attempted of which 36 (2.5%) were performed on women with a previous cesarean section. Although women with a history of previous cesarean section were more likely to be older and para >2 (38.93% vs. 15.0%), there were no difference in gestational age, estimated fetal weight, and amniotic fluid index. Women with a prior cesarean section had a success rate similar to women without [50.0% vs. 51.6%, adjusted OR: 1.31 (0.48-3.59)]. CONCLUSION: Women with a previous cesarean section who undergo an external cephalic version have similar success rates than do women without. Concern about procedural success in women with a previous cesarean section is unwarranted and should not deter attempting an external cephalic version. 

Eur J Obstet Gynecol Reprod Biol. 2009 Feb;142(2):111-4. doi: 10.1016/j.ejogrb.2008.08.012. Epub 2008 Nov 18. Safety and efficacy of external cephalic version for women with a previous cesarean delivery. Sela HY, Fiegenberg T, Ben-Meir A, Elchalal U, Ezra Y. PMID: 19019528

OBJECTIVE: To evaluate the success and morbidity rates for attempted external cephalic version (ECV) in patients with one previous cesarean delivery (CD) and a breech-presenting fetus at term. STUDY DESIGN: This is a retrospective study of outcomes of ECV at our institution for all women with one previous CD and a breech-presenting fetus at term between January 1997 and June 2005. A literature review was also performed as a Medline search (1966-2006). RESULTS: ECV was attempted for 42 women with a breech-presenting fetus and previous CD. The success rate of ECV was 74.0%, and 84% of women with successful ECV delivered vaginally. All fetal and maternal outcomes were favorable. Only four Medline reports met our inclusion criteria, representing a total of 124 patients and a mean ECV success rate of 76.6%. Thus we assessed 166 cases of attempted ECV and find an average ECV success rate of 76.5% and favorable fetal and maternal outcomes. CONCLUSIONS: Women with a breech-presenting fetus at term and previous CD, who desire a trial of labor, should be counseled regarding the accumulating evidence about the efficacy and apparently safety of this procedure and may be offered an ECV attempt.

Eur J Obstet Gynecol Reprod Biol. 1998 Oct;81(1):65-8. External cephalic version after previous cesarean section: a series of 38 cases. de Meeus JB1, Ellia F, Magnin G. PMID: 9846717

OBJECTIVE: To determine if external cephalic version (ECV) is a reasonable alternative to repeat cesarean section in case of breech presentation. STUDY DESIGN: Retrospective study of 38 women with one previous cesarean section and a breech presentation after 36 weeks of gestational age who have had at least one experience of ECV. Statistics used the Fisher's test with significance when P<0.05. RESULTS: Version attempts were successful in 25 of the 38 women (65.8%). Seventy-six percent of the successful version women went on to have vaginal birth after cesarean section. A total of 19 successful vaginal deliveries occurred (50%). Success rate of ECV was lowered when breech was the indication of the previous cesarean section. The vaginal delivery rate was increased after successful ECV in patients previously vaginally delivered, but this difference did not reached significance (P=0.057). No maternal or neonatal complications occurred. CONCLUSION: ECV is acceptable and effective in women with a prior low transverse uterine scar, when safety criteria are observed.

Int J Gynaecol Obstet. 1994 Apr;45(1):17-20. External cephalic version after previous cesarean section--a clinical dilemma. Schachter M, Kogan S, Blickstein I. PMID: 7913053

OBJECTIVES: To describe our limited experience with external cephalic version from breech to vertex presentation at term, with the use of ritodrine tocolysis, in women who had undergone a previous cesarean delivery. METHODS: Eleven parturients after previous cesarean delivery underwent external version after 36 gestational weeks, utilizing tocolysis with ritodrine, after excluding cases of low-lying placenta, severe oligohydramnion or ruptured membranes. Patients were then followed until delivery and scar examination was carried out after vaginal delivery, or at re-cesarean section, according to mode of delivery. RESULTS: All 11 attempted versions were successful. Six patients subsequently delivered vaginally and five by re-cesareansection. None of the uterine scars showed any signs of dehiscence. Three of the five infants delivered by re-cesarean section weighed over 4000 g, whereas all of the vaginally-delivered infants weighed under 3500 g. CONCLUSIONS: External cephalic version to vertex presentation after previous cesarean section was successful in all 11 carefully selected patients. No untoward effects were noted, and no signs of scar dehiscence were found. The safety and efficacy of this procedure after previous cesarean delivery should be examined further.

Am J Obstet Gynecol. 1991 Aug;165(2):370-2. External cephalic version after previous cesarean section. Flamm BL, Fried MW, Lonky NM, Giles WS. PMID: 1872341

Approximately 100,000 cesarean sections are performed each year in the United States because of breech presentation. Numerous studies have shown that external cephalic version can eliminate the need for many of these operations. However, because of the fear of uterine rupture, these studies have generally excluded patients who have undergone previous cesarean section. To evaluate the validity of this exclusion policy, we studied patients with one or more previous cesarean sections and breach presentations near term. Version attempts were successful in 82% of 56 patients who had undergone a previous cesarean section. Sixty-five percent of the successful version patients went on to have vaginal birth after cesarean section. There were no serious maternal or fetal complications associated with the version attempts. We conclude that external cephalic version is a reasonable option in patients with prior low transverse cesarean section.

VBAC After 2 Cesareans - Distorted Risk Perception

I recently wrote about ACOG's change in guidelines (August 2010), now "allowing" a trial of labor (TOL) again in women with 2 prior cesareans, whether or not they have had a prior vaginal birth.  This was a welcome change of policy and a breath of fresh air after many years of campaigning to get VBA2C back.

However, in the same post, I discussed the chilling effect that the earlier 2004 guidelines (which disallowed TOLs after 2 prior cesareans unless the woman had already had a prior vaginal birth) had had on the choices of women, and decried the reality that many women were forced into unnecessary repeat cesareans by these old guidelines.

The fact of the matter is that when ACOG makes these sweeping policy decisions (like all breeches should be born by cesarean, or VBAMC is not appopriate), it has MAJOR effects on the birthing climate in the world, effects that are not easily changed even if ACOG later recognizes its decisions were based on questionable research and changes its mind.

The net effect of disallowing VBAMC has been that only a few doctors in the world now "allow" women to choose a trial of labor after 2 prior cesareans, even though the risks associated with this have been shown to be reasonable. 

And although ACOG now "allows" a trial of labor after 2 cesareans, few OBs are rushing to change their policies.  The barn door is open, that horse is gone, and it's not coming back anytime soon.  I have hopes for change still, but I'm not holding my breath while waiting. The simple truth is that women are still being harmed by those old rules, even now.  ACOG has much to answer for.

This is similar to what has happened with breech births in the United States.  A flawed study came out that suggested that all breech babies were safer being born by cesarean, and BOOM, vaginal breech birth all but disappeared from the country, almost overnight.  Medical schools even quit teaching how to attend vaginal breech births, so many doctors now have no idea how to safely attend a surprise breech that shows up at the hospital. 

Research since the flawed breech study has questioned its conclusions and other recent studies have shown that vaginal breech birth is a reasonable option for most breech babies (and safer for the mother) ─ but it's close to too late to bring back the option because the art has been lost among so many providers.  Canada has been leading the way to try and get vaginal breeches re-established, but there's a long way to go.

As with breech, many doctors have developed an extremely distorted picture about risk with VBAC after two cesareans. 

And as with breech, all it took was one flawed study (Caughey 1999) that showed an abnormally high rate of rupture in VBA2C mothers, and ACOG rushed to virtually ban access to VBA2C. 

The problem is, that study had only 134 women in it, a sample size far too small to reliably determine risk (much less base sweeping policy decisions on); coincidence could easily have distorted the results.  No study before or since has shown such rates ─ but that didn't matter to ACOG.  It changed the rules, VBAMC was basically disallowed, and despite later research that showed the risk was not nearly as high as the Caughey study, VBAMC is still viewed by many as "far too risky" to even consider.  All on the basis of one very small, very flawed study.

Of course, some doctors have been overestimating the risk for uterine rupture in any VBAC  for years, but the degree of risk overestimation is especially egregious with VBA2C. 

Look at the following study, which surveyed doctors in France about their perceptions of the risks for uterine rupture with VBA1C and VBA2C.  The doctors overestimated the risk for rupture with both, but the overestimation was HUGE in the VBA2C group. 

In addition, they underestimated the risks associated with multiple repeat cesareans and counseled the women insufficiently about these.

As a result, less than a quarter of doctors surveyed would even consider "letting" a woman try a VBA2C trial of labor. 

The amazing thing is that this survey was published five years after major research showing far lower rupture rates in VBA2C mothers than these doctors estimated.

So what is the risk for rupture in VBA2C?  Studies vary, but the largest and most statistically powerful studies have shown rupture rates generally between 0.9% - 2.0% (Leung 1993, Miller 1994, Asakura 1995, Lin and Raynor 2004, Macones 2005, Landon 2006).

Tahseen and Griffiths (2010) did a meta-analysis of studies on VBA2C.  They found the average rupture rate was 1.36% and that the maternal morbidity between VBA2C and repeat cesarean was similar.

Note that all these studies include VBA2Cs with lots of induction and augmentation.  (Indeed, in Macones 2005, 16 of 19 ruptures in the VBA2C group were associated with induction or augmentation.)  With spontaneous labors only, the rupture risk for VBA2C would likely be even less.  (Never zero, alas, but less.)

What did the French doctors estimate the rupture risk to be with VBA2C?  14%!!!  Seven to fifteen times than the real risk.   

Distorted risk perception among doctors is one of the biggest things we battle on so many topics, from VBAC after multiple cesareans, to breech births, to pregnancy among women of size. 

AUGH.



Abstract

Vaginal birth after two previous c-sections: obstetricians-gynaecologists opinions and practice patterns. Doret M, Touzet S, Bourdy S, Gaucherand P.  J Matern Fetal Neonatal Med. 2010 Mar 17.

Hospices Civils de Lyon, Hôpital Femme-Mère-Enfant, Service d'obstétrique, F-69677 Bron, Lyon, France.

Objectives. To evaluate obstetricians' practice patterns, opinions and factors influencing decision-making about mode of delivery in women with two previous c-sections.

Methods. A questionnaire was mailed to the 160 obstetricians from the Rhone-Alpes perinatal network. Questionnaires included demographic, organisational information and questions about physicians' opinion, practice patterns and patient counseling concerning vaginal birth after c-section (VBAC) after one and two caesarean sections.

Results. Response rate was 65.6%; 100% and 23.8% would offer VBAC to women with respectively one and two previous c-sections.

Uterine rupture rate was largely overestimated in both women with one (2.8%) and two prior c-sections (14.2%).

Factors positively influencing obstetricians were cerebral palsy estimated rate less than 20%, a minimal decision to birth delay less than 20 min when emergency c-section would be required. Neonatal severe outcomes consecutive to trial of labour as well as placenta praevia or accreta risk and morbidity associated with multiple c-sections would be insufficiently discussed.

Conclusion. Obstetricians largely prefer a third planned c-section in women with two previous c-sections.

This decision is partly based on a large overestimation of immediate maternal and neonatal serious outcomes consecutive to trial of labour as well documented serious long term outcomes of multiple c-sections are insufficiently considered.  [sic]

PMID: 20233132