VBAC Risks and Benefits: A Review of the Evidence American College of Nurse Midwifery 2005 Washington, D.C. “Hot Topics” Betty-Anne Daviss, MA, RM Adjunct.

VBAC Risks and Benefits: A Review of the Evidence VBAC Risks and Benefits: A Review of the Evidence

American College of Nurse Midwifery 2005American College of Nurse Midwifery 2005Washington, D.C.Washington, D.C.

““Hot Topics”Hot Topics”Betty-Anne Daviss, MA, RM Betty-Anne Daviss, MA, RM

Adjunct Professor, Pauline Jewett Institute of Women’s Studies, Carleton Adjunct Professor, Pauline Jewett Institute of Women’s Studies, Carleton UniversityUniversity

&&Kenneth C. Johnson, PhD Kenneth C. Johnson, PhD

Centre for Chronic Disease Prevention and ControlCentre for Chronic Disease Prevention and ControlPublic Health Agency of CanadaPublic Health Agency of Canada

Overview of NACC Study RepercussionsOverview of NACC Study Repercussions

NACC study example of a trend in the use of NACC study example of a trend in the use of single studies to drive practicesingle studies to drive practice

Implications for the way “science” is usedImplications for the way “science” is used

Repercussions for American women on choiceRepercussions for American women on choice

Repercussions internationally on women’s choice Repercussions internationally on women’s choice in VBACin VBAC

Disturbing Trends Disturbing Trends

Single studies given more merit than warranted, often Single studies given more merit than warranted, often ignoring systematic reviewsignoring systematic reviews

1. Hannah, The Term Breech Trial (2000)1. Hannah, The Term Breech Trial (2000) 2. Pang et al. Washington Home Birth Study (2002)2. Pang et al. Washington Home Birth Study (2002) 3. Lydon Rochelle et al., NEJM VBAC study (2001)3. Lydon Rochelle et al., NEJM VBAC study (2001) 4. Lieberman et. al, NACC VBAC Study(2004)4. Lieberman et. al, NACC VBAC Study(2004)

1. Studies adopted to practice in isolation of former 1. Studies adopted to practice in isolation of former studies.studies.

2. Adoption of intervention occurred largely because 2. Adoption of intervention occurred largely because of editorials and high profile granted to the studies, of editorials and high profile granted to the studies, regardless of merit.regardless of merit.

3. Adoption almost immediate, prompted by hospital 3. Adoption almost immediate, prompted by hospital meetings, obstetric association directives, and mass meetings, obstetric association directives, and mass media.media.

Similarities in the Response to Similarities in the Response to The Single StudiesThe Single Studies

Similarities in the Response to Similarities in the Response to These Single StudiesThese Single StudiesSimilarities in the Response to Similarities in the Response to These Single StudiesThese Single Studies

4. Evidence of flaws in the studies or 4. Evidence of flaws in the studies or unwarranted conclusions were not published for unwarranted conclusions were not published for several months, by which time practice was several months, by which time practice was already changed, and reversal of the decision not already changed, and reversal of the decision not implemented.implemented.

5. Lack of inter-disciplinary or consumer/ 5. Lack of inter-disciplinary or consumer/ professional forums to discuss larger implications professional forums to discuss larger implications of change of practice.of change of practice.

6. Adoption of each study increased intervention.6. Adoption of each study increased intervention.

Meta-analyses Recommendations IgnoredMeta-analyses Recommendations Ignored

Rosen, Dickinson and Westhoff.Rosen, Dickinson and Westhoff. Vaginal Birth after cesarean: a meta-analysis of morbidity Vaginal Birth after cesarean: a meta-analysis of morbidity

and mortality.and mortality. Obstet Gynecol. March 1991 Obstet Gynecol. March 1991

Roberts et al.Roberts et al.

Trial of Labor or Repeated Cesarean SectionTrial of Labor or Repeated Cesarean Section Arch Fam Med Arch Fam Med Mar/Apr 1997Mar/Apr 1997

Mozurkewich and Hutton.Mozurkewich and Hutton. Elective Repeat Cesarean Delivery vs. Trial of Labor:AElective Repeat Cesarean Delivery vs. Trial of Labor:A

meta-analysis of the literature from 1989 to 1999meta-analysis of the literature from 1989 to 1999 Am J Am J Obstet Gynecol Nov 2000Obstet Gynecol Nov 2000

Meta-analyses RecommendationsMeta-analyses Recommendations

1. Rosen, Dickinson and Westhoff:1. Rosen, Dickinson and Westhoff:

VBAC appears to be a safe component of obstetric VBAC appears to be a safe component of obstetric care, and failed VBAC with consequent cesarean care, and failed VBAC with consequent cesarean poses no major risks.poses no major risks.

Need to modify Cragin’s original dictum to “Once Need to modify Cragin’s original dictum to “Once a cesarean, a trial of labour should precede a a cesarean, a trial of labour should precede a second cesarean except in the most unusual second cesarean except in the most unusual circumstances.”circumstances.”


2. Roberts R, Bell H, Wall E, Moy J, Hess G, Bower H2. Roberts R, Bell H, Wall E, Moy J, Hess G, Bower H

In balancing the potentially competing values of In balancing the potentially competing values of patient preferences vs cost containment, we patient preferences vs cost containment, we concluded that clinicians should counsel women concluded that clinicians should counsel women about the risks, benefits, and costs of TOL and about the risks, benefits, and costs of TOL and ERCS, and ERCS, and a guideline should recommend TOL, a guideline should recommend TOL, but respect a woman’s preference for ERCS.but respect a woman’s preference for ERCS.


3. Mozurkewich and Hutton.3. Mozurkewich and Hutton.

Small increases in the uterine rupture rate and in fetal and Small increases in the uterine rupture rate and in fetal and neonatal mortality rates may result from a trial of labor neonatal mortality rates may result from a trial of labor compared to elective repeat cesarean section.compared to elective repeat cesarean section.

These increases may be counterbalanced by reductions in These increases may be counterbalanced by reductions in maternal morbidity with a trial of labor, including febrile maternal morbidity with a trial of labor, including febrile morbidity, transfusion, and hysterectomy.morbidity, transfusion, and hysterectomy.

Either a trial of labor or elective repeat cesarean delivery Either a trial of labor or elective repeat cesarean delivery may be a reasonable option for women with at least one may be a reasonable option for women with at least one previous cesarean delivery.previous cesarean delivery.

Single study adopted Single study adopted

Lydon-Rochelle et al.Lydon-Rochelle et al.

Risk of uterine rupture during labor amongRisk of uterine rupture during labor among

women with a prior cesarean delivery women with a prior cesarean delivery NEJM NEJM 20012001

Risk of Uterine Rupture During Labor among VBACs (Lydon-Rochelle)

Risk of Uterine Rupture During Labor among VBACs (Lydon-Rochelle)

For women with one prior cesarean For women with one prior cesarean delivery, the risk of uterine rupture is higher delivery, the risk of uterine rupture is higher among those whose labor is induced than among those whose labor is induced than among those with repeated cesarean among those with repeated cesarean delivery without labour. Labour induced delivery without labour. Labour induced with a prostaglandin confers the highest with a prostaglandin confers the highest risk.risk.

How the Study Was UsedHow the Study Was Used

NEJM Editorial extrapolated NEJM Editorial extrapolated recommendations not contained in the studyrecommendations not contained in the study

Rather than commentary being we Rather than commentary being we shouldn’t do induction with VBACs, we shouldn’t do induction with VBACs, we shouldn’t do VBACsshouldn’t do VBACs

ACOG made use of the study at a press ACOG made use of the study at a press conference to announce to the media the conference to announce to the media the increased dangers of VBACincreased dangers of VBAC

Repercussions of the Lydon-Rochelle StudyRepercussions of the Lydon-Rochelle Study

All former meta-analyses ignoredAll former meta-analyses ignored Changed practice within a couple of monthsChanged practice within a couple of months Response in letters to the editor of the Response in letters to the editor of the

NEJM and the BMJ not published for six NEJM and the BMJ not published for six monthsmonths

% VBAC Low Risk* Mothers, U.S., 1990-2001% VBAC Low Risk* Mothers, U.S., 1990-2001

10%

14%

18%

22%

26%

30%

* Full-gestation(37+ weeks), vertex presentation, singleton births

Current Changes:National Cesarean Rates

1990-2002

Current Changes:National Cesarean Rates

1990-2002

5%

10%

15%

20%

25%

30%

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002

England

U.S.

Netherlands

Germany

VBAC deliveries - USA 1989-2003VBAC deliveries - USA 1989-2003

National Study of Vaginal Birth After Cesarean in Birth Centers (NACC Study)National Study of Vaginal Birth After Cesarean in Birth Centers (NACC Study)

Prospective study of 1453 attempted Prospective study of 1453 attempted VBACs in 41 U.S. Birth Centers – 1990-VBACs in 41 U.S. Birth Centers – 1990-20002000

24% transfer to hospital24% transfer to hospital 87% VBAC success87% VBAC success

NACC Study Uterine RuptureNACC Study Uterine Rupture

CategoryCategory Perinatal DeathsPerinatal Deaths Uterine RuptureUterine Rupture

1 Previous 1 Previous cesareancesarean

3 in 12713 in 1271 2/10002/1000

2 Previous 2 Previous cesareanscesareans

3 in 99 3 in 99 30/100030/1000

NACC Study Perinatal DeathNACC Study Perinatal Death

CategoryCategory Fetal & Fetal & Neonatal Death Neonatal Death RateRate

Fetal & Fetal & Neonatal Death Neonatal Death RateRate

1 Previous 1 Previous cesareancesarean

3 in 12713 in 1271 2/10002/1000

2 Previous 2 Previous cesareanscesareans

3 in 99 3 in 99 30/100030/1000

>or= 42 wks.>or= 42 wks. 1 in 461 in 46 20/100020/1000

NACC Study ConclusionsNACC Study Conclusions

““Despite a high rate of vaginal births and few uterine Despite a high rate of vaginal births and few uterine ruptures among women attempting VBACs in birth ruptures among women attempting VBACs in birth centers, a caesarean-scarred uterus was associated with centers, a caesarean-scarred uterus was associated with increases in complications that require hospital increases in complications that require hospital management. management.

Therefore, birth centers should refer women who have Therefore, birth centers should refer women who have undergone previous cesarean deliveries to hospitals for undergone previous cesarean deliveries to hospitals for delivery. Hospitals should increase access to in-delivery. Hospitals should increase access to in-hospital care provided by midwife/obstetrician teams hospital care provided by midwife/obstetrician teams during VBACs.”during VBACs.”

Using the same logic:Using the same logic:

Because women of lower socio-economic Because women of lower socio-economic status have higher risk of perinatal death,status have higher risk of perinatal death,

they should all go to the best tertiary care they should all go to the best tertiary care hospitals.hospitals.

Using Similar Logic:Using Similar Logic:

Landon MB et al. found:Landon MB et al. found:

7 maternal deaths in 15, 801 elective cesareans 7 maternal deaths in 15, 801 elective cesareans

3 maternal deaths in 17, 898 attempted VBACs3 maternal deaths in 17, 898 attempted VBACs

We could therefore conclude that elective caesarean We could therefore conclude that elective caesarean section should not be done in academic institutionssection should not be done in academic institutions

Alternative ConclusionsAlternative Conclusions

Because in this study there was a high rate of Because in this study there was a high rate of vaginal births and few uterine ruptures vaginal births and few uterine ruptures among women attempting VBACs in birth among women attempting VBACs in birth centers,centers,

And because the perinatal mortality of 2 per And because the perinatal mortality of 2 per thousand in those with a single former thousand in those with a single former caesarean section is very low (consider the caesarean section is very low (consider the overall perinatal mortality in the USA) overall perinatal mortality in the USA)

Alternative ConclusionsAlternative Conclusions

therefore, reflection for those planning VBACS in out of therefore, reflection for those planning VBACS in out of hospital births should be more cautious if they have had hospital births should be more cautious if they have had two former caesarean sections or are >=42 weeks.two former caesarean sections or are >=42 weeks.

Women should also be told about the risk of cesareans along Women should also be told about the risk of cesareans along with the risks of VBACs and ruptures (Cesarean risks with the risks of VBACs and ruptures (Cesarean risks include increased odds of infertility, miscarriage, ectopic include increased odds of infertility, miscarriage, ectopic pregnancy, placenta abruption, praevia and accreta, pregnancy, placenta abruption, praevia and accreta, respiratory problems including persistent pulmonary respiratory problems including persistent pulmonary hypertension)hypertension)

WHO: Beyond the NumbersWHO: Beyond the Numbers

““Knowing the level of maternal mortality is not Knowing the level of maternal mortality is not enough; we need to understand the underlying enough; we need to understand the underlying factors that led to the deaths.factors that led to the deaths.

““Each maternal death or case of life-threatening Each maternal death or case of life-threatening complications has a story to tell and can provide complications has a story to tell and can provide indications on practical ways of addressing the indications on practical ways of addressing the problem.”problem.”

Perinatal AuditsPerinatal Audits

ConsiderationsConsiderations

Individual AuditIndividual Audit

Responsibilities when publishing the Responsibilities when publishing the numbersnumbers

Without giving context and precautions Without giving context and precautions about how “the numbers” will be usedabout how “the numbers” will be used

ImplicationsImplications

Implications for the way “science” is usedImplications for the way “science” is used

Repercussions for American women on Repercussions for American women on choicechoice

Repercussions internationally on women’s Repercussions internationally on women’s choice in VBACchoice in VBAC

Repercussions InternationallyRepercussions Internationally

ACNM VBAC protocols – out-of-hospital ACNM VBAC protocols – out-of-hospital settingsetting

Are American standards based on research?Are American standards based on research?

Reconsider what access to “immediate” Reconsider what access to “immediate” caesarean section meanscaesarean section means

Society of Obstetricians and Gynaecologists of CanadaSociety of Obstetricians and Gynaecologists of Canada

The word “timely” has replaced The word “timely” has replaced “immediate.”“immediate.”

30 minutes is timely enough30 minutes is timely enough

ConclusionsConclusions

Choice of birth place is multi-factorial, Choice of birth place is multi-factorial, based on science, liability, culturebased on science, liability, culture

Evaluate where risks are to inform women Evaluate where risks are to inform women and caregiversand caregivers

ReferencesReferences

1. 1. Lieberman E, et al. Results of the national study of Lieberman E, et al. Results of the national study of vaginal birth after cesarean in birth centers. Obstet vaginal birth after cesarean in birth centers. Obstet GynecolGynecol.. 2004;104:933-42. 2004;104:933-42.

2. Maternity Center Association. 2. Maternity Center Association. What Every Pregnant What Every Pregnant Woman Needs to Know About Cesarean SectionWoman Needs to Know About Cesarean Section.. New New York: MCA, 2004.York: MCA, 2004.

3. Landon MB. et al. Maternal and perinatal outcomes 3. Landon MB. et al. Maternal and perinatal outcomes associated with a trial of labour after prior cesarean associated with a trial of labour after prior cesarean delivery. NEJM. 2004;351(25);2581-89. delivery. NEJM. 2004;351(25);2581-89.

4. Johnson KC and Daviss BA. Re:4. Johnson KC and Daviss BA. Re:Results of the national Results of the national study of vaginal birth after cesarean in birth centers. Obstet study of vaginal birth after cesarean in birth centers. Obstet GynecolGynecol.. 2005 in Press April 2005. 2005 in Press April 2005.

Letters to the editor re Lydon-Rochelle in BMJ December 2001

Letters to the editor re Lydon-Rochelle in BMJ December 2001

Daviss BADaviss BA 1. Study’s focus on induction v spontaneous labour 1. Study’s focus on induction v spontaneous labour

neglects spontaneous deliveryneglects spontaneous delivery (Study did not provide comparison group of women with (Study did not provide comparison group of women with

no intervention because did not stratify for oxytocic use)no intervention because did not stratify for oxytocic use)

Johnson K, Gaskin IJohnson K, Gaskin I 2. Safety of single-layer suturing in caesarean sections 2. Safety of single-layer suturing in caesarean sections

must be proven (the apparent increase in TOL rupture rates must be proven (the apparent increase in TOL rupture rates in the 1990’s may have been caused by a change to single in the 1990’s may have been caused by a change to single layer suturing of the uterine incision – not evidence based)layer suturing of the uterine incision – not evidence based)

Letters to the Editor re Lydon Rochelle in NEJM Jan 2002


Heffner, L. Brigham and Women’s hospital Heffner, L. Brigham and Women’s hospital

3. Study doesn’t provide incremental risks (absolute risks) of 3. Study doesn’t provide incremental risks (absolute risks) of perinatal mortality with each category of delivery, only the perinatal mortality with each category of delivery, only the relative risk of infant death should rupture occurrelative risk of infant death should rupture occur

Incremental Risk:Incremental Risk: Csect: 0.09 deaths per 1000Csect: 0.09 deaths per 1000 Spontaneous Labour: 0.28 deaths per 1000Spontaneous Labour: 0.28 deaths per 1000 VBAC Induction: 0.47 deaths per 1000VBAC Induction: 0.47 deaths per 1000 2% increase in perinatal mortality from 5.2 to 5.4 per 1000 2% increase in perinatal mortality from 5.2 to 5.4 per 1000

birthsbirths Bottom Line: Study suggests non-induced VBAC may result in Bottom Line: Study suggests non-induced VBAC may result in

less than 1 excess death per 5,000 births less than 1 excess death per 5,000 births



Weiss J, Bartlett, L Massachusetts Dep’t Public HealthWeiss J, Bartlett, L Massachusetts Dep’t Public Health

4. Diagnostic codes (ICD 665.0 and 665.1) to identify 4. Diagnostic codes (ICD 665.0 and 665.1) to identify uterine rupture not used exclusively for ruptures. uterine rupture not used exclusively for ruptures.

Massachusetts’ study – with chart review:Massachusetts’ study – with chart review: ½ of those coded to 665.0 & 665.1 – not ruptures ½ of those coded to 665.0 & 665.1 – not ruptures 1/3 of ruptures missed – (coded using ICD Code 674)1/3 of ruptures missed – (coded using ICD Code 674)



Magee, D M.D., MassachusettsMagee, D M.D., Massachusetts

8. Critiques Greene’s assertion that “most reasonable 8. Critiques Greene’s assertion that “most reasonable women… would choose a caesarean if told uterine rupture women… would choose a caesarean if told uterine rupture raises the risk of infant death by a factor of 10,” by raises the risk of infant death by a factor of 10,” by reminding readers this is a relative risk in a rare event.reminding readers this is a relative risk in a rare event.

Suggests instead the data from this particular article should Suggests instead the data from this particular article should be presented as: “the rate of perinatal death with a repeated be presented as: “the rate of perinatal death with a repeated cesarean is just over 3 in 1000 births; if you choose to have cesarean is just over 3 in 1000 births; if you choose to have a trial of labour, the rate is just below 6 in 1,000 births.a trial of labour, the rate is just below 6 in 1,000 births.



Koroukian, S, Case Western Reserve University, Koroukian, S, Case Western Reserve University, Cleveland OHCleveland OH

7. 7. Re-Green’s editorial: Greene discussed Re-Green’s editorial: Greene discussed informed consent. Will the information presented informed consent. Will the information presented to women undergoing primary caesarean include to women undergoing primary caesarean include the increased risk of uterine rupture in future even the increased risk of uterine rupture in future even without the spontaneous onset of labour? And the without the spontaneous onset of labour? And the near certainty of caesarean next time?near certainty of caesarean next time?

Conclusion on VBAC IssueConclusion on VBAC Issue

Study conclusions of questionable merit are being used in Study conclusions of questionable merit are being used in isolation rather than as part of a synthesis of the literatureisolation rather than as part of a synthesis of the literature

Publicity, not always merit, is dictating which studies become Publicity, not always merit, is dictating which studies become acceptableacceptable

Letters to the editor do not seem to be able to undo the political Letters to the editor do not seem to be able to undo the political drive to increase interventions based on these studies’ drive to increase interventions based on these studies’ interpretationinterpretation

The more credibility the questionable studies are given the more The more credibility the questionable studies are given the more intervention will be subsequently requiredintervention will be subsequently required

VBAC Risks and Benefits: A Review of the Evidence American College of Nurse Midwifery 2005 Washington, D.C. “Hot Topics” Betty-Anne Daviss, MA, RM Adjunct.

Documents

trial of labor

consequent cesarean

vbac risks

nejm vbac study

trial of labour

metaanalyses recommendations2

metaanalyses recommendations1

metaanalyses recommendations3