Trial of Labor and Vaginal Delivery Rates in Women with Prev CS

8/19/2019 Trial of Labor and Vaginal Delivery Rates in Women with Prev CS

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JOGNN R E V I E W

Trial of Labor and Vaginal Delivery

Rates in Women with a Prior CesareanKaren B. Eden, Mary Anna Denman, Cathy L. Emeis, Marian S. McDonagh, Rongwei Fu, Rosalind K. Janik,Alia R. Broman, and Jeanne-Marie Guise

Correspondence

Karen B. Eden, PhD,

Department of Medical

Informatics and Clinical

Epidemiology, Oregon

Health and Science

University, 3181 SW Sam

Jackson Park Rd, Portland,

OR 97229.

[email protected]

Keywords

VBAC

trial of labor

pregnancy

predictors

cesarean

evidence review

ABSTRACT

Objective: To evaluate evidence on trial of labor (TOL) and vaginal delivery rates in women with a prior cesarean and

to understand the characteristics of women offered a trial of labor.

Data Sources: MEDLINE, DARE, and Cochrane databases were searched for articles evaluating mode of delivery for

women with a prior cesarean delivery published between 1980 and September 2009.

Study Selection: Studies were included if they involved human participants, were in English, conducted in the United

States or in developed countries, and if they were rated fair or good base on U.S. Preventive Services Task Force

(USPSTF) criteria.

Data Extraction and Synthesis: The search yielded 3,134 abstracts: 69 full-text papers on TOL and vaginal birth

after cesarean (VBAC) rates and 10 on predictors of TOL. The TOL rate in U.S. studies was 58% (95% CI [52, 65])

compared with 64% (95% CI [59, 70]) in non U.S. studies. The TOL rate in the U.S. was 62% (95% CI [57, 66]) for

studies completed prior to 1996 and dropped to 44% (95% CI [34, 53]) in studies launched after 1996, p = .016. In U.S.

studies, 74% (95% CI [72, 76]) of women who had a TOL delivered vaginally. Women who had a prior vaginal birth or

delivered at a large teaching hospital were more likely to be offered a TOL.

Conclusions: Although the TOL rate has dropped since 1996, the rate of vaginal delivery after a TOL has remained

constant. Efforts to increase rates of TOL will depend on patients understanding the risks and benefits of both options.

Maternity providers are well positioned to provide key education and counseling when patients are not informed of their

options.

JOGNN, 41, 583-598; 2012. DOI: 10.1111/j.1552-6909.2012.01388.x

Accepted March 2012

Karen B. Eden, PhD, is an

associate professor in the

Oregon Evidence-based

Practice Center,

Department of Medical

Informatics and Clinical

Epidemiology, Oregon

Health and Science

University, Portland, OR.

Mary Anna Denman, MD,

MCR, is an assistant

professor in the Department

of Obstetrics and

Gynecology, Oregon Healthand Science University,

Portland, OR.

(Continued)

Prior to 1996, in the United States, the num-

ber of women having a vaginal birth after ce-

sarean (VBAC) reached an all-time high of 28%

(Menacker, Declercq, & Macdorman, 2006). How-

ever, with the release of information on uterine rup-

ture in 1996 (McMahon, Luther, Bowes, & Olshan,

1996), the number of women undergoing a trial of

labor (TOL) began to steadily decline. In 1999, the

American College of Obstetricians and Gynecolo-

gists (ACOG; 1999) recommended that hospitals

offering VBAC should have a surgical team imme-

diately available throughout labor. Some hospitalsunable to provide an immediate surgical response

and concerned about liability during labor prohib-

ited the practice of VBAC, which left some women

with no option for a TOL (Scott, 2010; Shorten,

2010). In one study, the authors reported that

prior to the 1999 ACOG guideline, 24% of eligi-

ble women in California hospitals had a TOL, and

immediately following the release, 13.5% of eligi-

ble women made the attempt, p < .001 (Zweifler

et al., 2006). When questioned, a majority (85%) of

physicians cited the updated ACOG guideline as

one of many “most important” factors to consider

when recommending VBAC (Coleman, Erickson,

Schulkin, Zinberg, & Sachs, 2005). The culmina-

tion of these events led to a national VBAC rate of

8.3% in 2007 (Martin et al., 2010).

A reduction in the national VBAC rate could be

attributed to fewer women having TOLs (fewer

providers and hospitals offering TOLs or fewer

women at eligible sites being allowed TOLs), fewerwomen who have TOLs and who deliver vaginally,

and/or a combination of factors. Because not all

settings allow TOL, this report provides a system-

atic review of the literature regarding TOL rates

and the subsequent vaginal delivery rates in set-

tings that allowed it. Because of variation in the

rate of TOL, we evaluated underlying health care

barriers (and enablers) found in the literature that

may have affected whether women were offered a

Disclosure: The authors re-port no conflict of interestor relevant financial rela-tionships.

http://jognn.awhonn.org C 2012 AWHONN, the Association of Women’s Health, Obstetric and Neonatal Nurses 583


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R E V I E W TOL and VBAC rates

TOL. This systematic review was part of a larger

evidence report on VBAC conducted to inform the

U.S. 2010 National Institutes of Health (NIH) Con-

sensus Development Conference: Vaginal Birth

After Cesarean: New Insights (Guise, Denman,

et al., 2010; Guise, Eden, et al., 2010).

MethodsData Sources

Together with a medical librarian, we searched

MEDLINE, Database of Abstracts of Reviews of

Effectiveness (DARE), and the Cochrane Library

from 1980 to September 2009 using methods de-

scribed previously (Guise, Denman, et al., 2010;

Guise, Eden, et al., 2010). The search was limited

to publications after 1980 when the NIH held a

consensus conference that concluded that VBAC

was an acceptable option and resulted in changes

in practice. The searches included variations of

the terms VBAC, prior cesarean , and trial of la-

bor . Additional articles were identified from refer-

encelists of reviews and editorials and through the

peer review process. The abstracts retrieved from

the searches were then entered into an electronic

database. This search was part of a larger search

that addressed several topics for the evidence re-

port related to TOL and VBAC rates, predictors of

TOL and VBAC, benefits and harms to mothers

and infants for TOL, and repeat cesarean (Guise,

Denman, et al.; Guise, Eden, et al.).

Study Selection

Cathy L. Emeis, PhD,

CNM, is an assistant

professor in the School of

Nursing, Oregon Health

and Science University,

Portland, OR.

Marian S. McDonagh,

PharmD, is an associate

professor in the Oregon

Evidence-based Practice

Center, Department of

Medical Informatics and

Clinical Epidemiology,

Oregon Health and Science


Rongwei Fu, PhD, is an

associate professor in the

Oregon Evidence-based

Practice Center,

Department of Public

Health and Preventive

Medicine and the

Department of EmergencyMedicine, Oregon Health

and Science University,

Portland, OR.

Rosalind K. Janik, BA, is a

project manager at Epic

Systems Corporation,

Verona, WI.

Alia R. Broman, BA, is a

student at the medical

school at the University of

Colorado, School of

Medicine, Aurora, CO.

Jeanne-Marie Guise, MD,

MPH, is an associatedirector for the Oregon

Evidence-based Practice

Center and an associate

professor in the Department

of Medical Informatics and

Clinical Epidemiology,

Department of Obstetrics

and Gynecology and

Department Public Health

and Preventive Medicine,

Oregon Health and Science


Full-text studies were included if they explicitly re-

ported on eligibility for TOL and if they provided

data for computing theTOL rate or vaginal delivery

rate after a TOL at the study sites. We were partic-

ularly interested in studies that provided informa-

tion on influencing factors and predictors of TOL.

Non-U.S. studies were included if the study was

conducted in a developed country because the

available technology and medical response were

thought to be similar to the United States and were

published in English (The World Factbook , 2008).

Two investigators reviewed each full-text article for

inclusion or exclusion. We excluded studies that

included women without a prior cesarean deliv-

ery, nulliparous patients, 10 participants or fewer,

breech delivery, exclusive focus on preterm de-

livery or low birth weight, multiple gestation, or

abortions.

Data Extraction and Quality Rating

Reviewers rated the quality of each study using

criteria developed by the U.S. Preventive Services

Task Force (USPSTF) and the National Health Ser-

vice Centre for Reviews and Dissemination (Harris

et al., 2001; Healthy Inclusion, 2001). Two review-

ers independently reviewed the studies. When

reviewers disagreed, a final rating was reached

through discussion and consensus of the whole

team. Studies that were rated as poor quality were

excluded from analyses. Parameters that were

particularly important for TOL and VBAC rates

were clear definition of eligibility for TOL, com-

parable groups, reliable and valid outcomes, un-

biased assessment of measures, follow-up long

enough for outcome to occur, acceptable level

of attrition (≤40%), and adjustment for potential

confounders (Guise, Denman, et al., 2010; Guise,

Eden, et al., 2010). For studies reporting on the

factors influencing or predicting TOL, clear defini-

tion of all factors was critical (Guise, Eden, et al.).

Data from included papers were extracted by one

researcher into evidence tables and verified by a

second.

Analysis

Meta-analyses were conducted using a random

effects model (DerSimonian & Laird,1986) to sum-

marize TOL and vaginal delivery rates. Statistical

heterogeneity was assessed by using the stan-

dard chi-squared test and the I 2 statistic (the

proportion of variation in study estimates due to

heterogeneity rather than sampling error) (Hig-

gins, Thompson, Deeks, & Altman, 2003; Hig-

gins, Thompson, Higgins, & Thompson, 2002).

To explore heterogeneity, we performed subgroup

analyses and meta-regression (Sutton, Abrams,

Jones, Sheldon, & Song, 2000; Thompson &

Sharp, 1999) to evaluate whether the summary

estimates differed by study-level characteristics,

including U.S. versus non-U.S. population, ges-

tational age of the population (term vs. any ges-

tational age), and year of data collection of the

study.

ResultsAs shown in Figure 1, of 3,134 citations identified

in searches, 963 full-text papers were reviewed

and 69 studies that contained adequate data tocompute the TOL and/or vaginal delivery rate, and

10 studies on predictors of TOL met the inclusion

and quality standards. We included 19 studies of

good quality and 50 studies of fair quality that pro-

vided evidence on TOL and VBAC rates (Table 1).

The majority (7 of 10) of the studies providing

evidence on individual predictors were of good

quality (Cameron, Roberts, & Peat 2004; Chang,

Stamilio, & Macones, 2008; DeFranco et al., 2007;

584 JOGNN, 41, 583-598; 2012. DOI: 10.1111/j.1552- 6909.2012.01388.x http://jognn.awhonn.org


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Eden, K.B. et al. R E V I E W

Figure 1. Search and Selection of Literature for TOL rate and Vaginal Delivery Rate after TOL.

TOL = trial of labor; VBAC = vaginal birth after cesarean.

aSearched databases included MEDLINE, Cochrane and DARE.

bMany studies areincludedin more than onetopicarea.Adaptedwithpermissionfrom Guise,J. M.,Eden, K.,Emeis,C.,Denman,

M., Marshall, N., Fu, R., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology

AssessmentNo. 191 (AHRQpublication no.10-E001).Rockville, MD: Agency forHealthcareResearch and Quality. Alsoadapted

with permission from Wolters Kluwer. from Eden, K.B., (2010). New insights on vaginal birth after cesarean, can it be predicted?

Obstetrics & Gynecology , 116 (4), 967–981.

Harper et al., 2009; Kabir, Pridjian, Steinmann,Herrera, & Khan, 2005; McMahon et al., 1996;

Pang, Law, Leung, Lai, & La 2009), and the re-

mainder (3 of 10) were fair quality (Bujold, 2001;

Hueston & Rudy, 1994; Selo-Ojeme, Abulhassan,

Mandal, Tirlapur, & Selo-Ojeme 2008).

TOL Rate

Thirty-five studies consisting of 10 prospective

and 25 retrospective cohort studies provided data

on TOL rates (Table 1). These studies included

661,765 women and provided a combined TOL

rate of 61% (95% CI [57, 65]). However, the ratesof TOL significantly variedacross thestudies rang-

ing from 28% to 82% (p < .0001) with an I 2

for between-heterogeneity of greater than 99%

(Figure 2). Results from metaregression indicated

that TOL rates differed significantly by gestational

age and year of study (p


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Table 1: Evidence for TOL and Vaginal Delivery Rates

Study Quality U.S. or Cohort Evidence Evidence for

Non-U.S. Design for TOL Vaginal Delivery

after TOLa

Bais, 2001 Fair Non Prospective X X

Cameron, 2004 Good Non Retrospective X X

Caughey, 1999 Fair US Retrospective X

Costantine, 2009 Good US Retrospective X (Term)

De Franco, 2007 Good US Retrospective X X

Delaney, 2003 Fair Non Retrospective X

DiMaio, 2002 Fair US Retrospective X X (Term)

Dinsmoor, 2004 Fair US Retrospective X

Durnwald, 2004a Fair US Retrospective X

Durnwald, 2004b Fair US Retrospective X X

El-Sayed, 2007 Fair US Retrospective X (Term)

Elkousy, 2003 Fair US Retrospective X (Term)

Fisler, 2003 Fair US Retrospective X X (Term)

Flamm, 1987 Fair US Retrospective X

Flamm, 1994 Good US Prospective X X

Gonen, 2006 Fair Non Retrospective X X

Goodall, 2005 Fair US Retrospective X

Gregory, 1999 Good US Retrospective X X

Gregory, 2008 Fair US Retrospective X X (Term)

Gyamfi, 2004 Good US Retrospective X (Term)

Hammoud, 2004 Fair Non Retrospective X

Hashima, 2007 Fair US Retrospective X (Term)

Hendler, 2004 Good Non Prospective X

Hibbard, 2006 Good US Prospective X X (Term)

Hollard, 2006 Good US Retrospective X

Hook, 1997 Good US Prospective X X (Term)

Horenstein, 1984 Fair US Retrospective X

Horenstein, 1985 Fair US Retrospective X

Hoskins, 1997 Fair US Retrospective X

Huang, 2002 Fair US Retrospective X (Term)

Hueston, 1994 Fair US Retrospective X

Jakobi, 1993 Good Non Prospective X

Johnson, 1991 Fair US Retrospective X

Juhasz, 2005 Fair US Retrospective X

Kugler, 2008 Fair Non Retrospective X X

Landon, 2006 Fair US Prospective X X

Learman, 1996 Good US Retrospective X



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Table 1: Continued

Study Quality U.S. or Cohort Evidence Evidence for

Non-U.S. Design for TOL Vaginal Delivery

after TOLa

Lieberman, 2004 Fair US Prospective X

Locatelli, 2004 Good Non Retrospective X X

Loebel, 2004 Fair US Retrospective X X (Term)

Macones, 2005 Fair US Retrospective X X

McMahon, 1996 Good Non Retrospective X X

McNally, 1999 Fair Non Retrospective X

Nguyen, 1992 Fair US Retrospective X

Obara, 1998 Fair Non Retrospective X X

Ouzounian, 1996 Fair US Retrospective X

Pang, 2009 Good Non Retrospective X X (Term)

Pathadey, 2005 Fair Non Retrospective X

Phelan, 1987 Fair US Prospective X X

Pickhardt, 1992 Fair US Retrospective X X

Raynor, 1993 Fair US Retrospective X

Rozenberg, 1996 Good Non Prospective X X

Rozenberg, 1999 Fair Non Prospective X X

Sakala, 1990 Fair US Retrospective X

Selo-Ojeme, 2008 Fair Non Retrospective X X (Term)

Smith, 2002 Good Non Retrospective X X (Term)

Smith, 2005 Good Non Retrospective X X (Term)

Socol, 1999 Fair US Retrospective X X

Spaans, 2002 Fair Non Retrospective X X

Stovall, 1987 Fair US Prospective X X

Strong, 1996 Fair Non Prospective X X

Troyer, 1992 Fair US Retrospective X X (Term)

van Gelderen, 1986 Fair Non Prospective X

Vinueza, 2000 Fair US Retrospective X

Weinstein, 1996 Good Non Retrospective X

Wen, 2004 Fair Non Retrospective X X (Term)

Yetman, 1989 Fair US Retrospective X

Yogev, 2004 Fair Non Retrospective X

Zelop, 2001 Fair US Retrospective X

Note. TOL = trial of labor.aUnless noted by “Term,” the studies accepted women of all gestational ages (term and preterm).

Lieberman, 2003; Flamm, Goings, Liu, & Wolde-

Tsadik, 1994; Gregory, Korst, Cane, Platt, & Kahn,

1999; Hook, Kiwi, Amini, Fanaroff, & Hack, 1997;

Hueston & Rudy, 1994; Phelan, Clark, Diaz, &

Paul, 1987; Pickhardt et al., 1992; Stovall, Shayer,

Solomon, & Anderson, 1987; Troyer & Parisi,

1992), 63% (95% CI [58, 67]) for U.S. studies that

included 1996 (DeFranco et al., 2007; Durnwald &

JOGNN 2012; Vol. 41, Issue 5 587


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Figure 2. Trial of labor in studies conducted in the United States and outside the United States. Adapted with permission from Guise, J. M., Eden, K., Emeis,

C., Denman, M., Marshall, N., Fu, R., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No. 191

(AHRQ publication no. 10-E001). Rockville, MD: Agency for Healthcare Research and Quality.

Mercer, 2004b; Loebel, Zelop, Egan, & Wax, 2004;

Macones et al., 2005; Socol & Peaceman, 1999),

and 44% (95% CI [34, to 53] for U.S. studies initi-ated after 1996 (DiMaio, Edwards, Euliano, Treloar,

& Cruz, 2002; Gregory et al., 2008; Landon et al.,

2006). The TOL was significantly lower than the

rate prior to 1996 (p = .016) or that included 1996

(p = .019) (Figure 3). A similar trend was present

for non-U.S. studies (Figure 3).

Almost all studies providing TOL rates were con-

ducted in tertiary care centers such as teach-

ing hospitals with residents and 24-hour anes-

thesia teams available; therefore, findings have

limited applicability to rural settings. We found

two retrospective studies completed before 1996(Hueston & Rudy, 1994; McMahon, 1996) that re-

ported reduced attempts (TOL rates ranging from

36%–41%) for rural settings compared with ur-

ban and/or teaching settings (TOL rates ranged

from 60%–69%). In one retrospective study com-

pleted 1998 to 2001 (Cameron, 2004), the authors

reported that rural sites had a TOL rate of 47%

compared with 55% for a perinatal center set-

ting. Finally, a retrospective study launched and

completed in 2001 indicated that 70% of repeat

cesarean deliveries (RCD) in rural settings were

potentially unnecessary compared with 61% in ur-ban teaching settings that is consistent with find-

ings above (Kabir, 2005). The authors in this study

coded a cesarean as “potentially unnecessary”

if it lacked an associated discharge diagnosis to

justify it. A diagnosis of a prior cesarean delivery

alone was not considered sufficient justification for

a repeat cesarean. Although we could not statisti-

cally analyze these results, they suggest that the

rates of TOL are lower in rural settings than non-

rural settings and that the TOL rates across sites

may have dropped since 1996.

Vaginal Delivery Rate with TOL

Sixty-seven studies including 14 prospective co-

hort studies and 53 retrospective cohort stud-

ies (Table 1) provided data on VBAC rate from

368,304 women. The range in VBAC rates across

studies inside and outside the United States was

49% for a high-birth-volume hospital in London

(Selo-Ojeme, 2008) to 87% for a national study of

U.S. birth centers (Lieberman, 2004) (Figures 5



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Figure 3. Global trial of labor rates have dropped over time.

Adapted with permission from Guise, J. M., Eden, K., Emeis, C., Denman, M., Marshall, N., Fu, R., . . . McDonagh, M. (2010).

Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No. 191 (AHRQ publication no. 10-E001).

Rockville, MD: Agency for Healthcare Research and Quality.

and 6), and the overall summary estimate for

the vaginal delivery rate from the random ef-

fects model was 74% (95% CI [72, 75]). How-

ever, there was significant heterogeneity among

included studies (p < .001) with I 2 = 98.6%.

Metaregression was conducted to assess the as-

sociation between vaginal delivery rates with TOL

and country, gestation, true cohort (study included

TOL and elective repeatcesarean delivery [ERCD]

vs. studies of TOL only), and by years when the

data were collected. None of these factors could

explain the variation among studies. The summary

estimates were similar: for the 43 studies con-

ducted in the United States, 74% (95% CI [72, 76])

of women had a vaginal delivery compared to 73%

(95% CI[71, 74]) for the 24 studies conducted out-

side the United States (Table 1). In examining the

gestational age for enrolled patients, the summary

estimates were again similar: for the 18 studies of

term deliveries, 73% (95% CI [71, 75]) of women

delivered vaginally compared to 74% (95% CI [72,

76]) for the 49 studies that included preterm and

term deliveries (Table 1).

Figure 4. TOL and vaginal delivery rates with TOL over time.



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Figure 5. Rate of vaginal delivery with TOL in studies conducted in the United States.

Reprinted with permission from Guise, J. M., Eden, K., Emeis, C., Denman, M., Marshall, N., Fu, R., . . . McDonagh, M. (2010).

Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No. 191 (AHRQ publication no. 10-E001).

Rockville, MD: Agency for Healthcare Research and Quality.

Using only the subset of the U.S. studies that pro-

vided data to compute the TOL and vaginal de-

livery rates with TOL, the rates were ordered by

year the data collection was launched (ranged

between 1982–2002) and plotted together on the

same chart, Figure 4. With the exception of one

retrospective study that focused on costs of de-

livery for a cohort of 204 women with a prior

low transverse cesarean (DiMaio, 2002, shown in

Figure 4), the TOL rates in U.S. studies (shown

by the diamonds) have dropped dramatically over

the last 15 years. The first drop was seen after

1996when McMahon’s (1996) evidence on uterine

rupture and other complications was published.



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Figure 6. Rate of vaginal delivery with TOL in studies conducted outside the United States.

Reprinted with permission from Guise, J. M., Eden, K., Emeis, C., Denman, M., Marshall, N., Fu, R., . . . McDonagh, M. (2010).

Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No. 191 (AHRQ publication no. 10-E001).Rockville, MD: Agency for Healthcare Research and Quality.

A second dramatic decrease was seen in two

multisite cohort studies that enrolled patients after

the 1999 ACOG guideline on VBAC was released

(Gregory et al., 2008; Landon et al., 2006). How-

ever, during the same time period of 1982 to 2002,

the vaginal delivery rates with TOL (shown by the

squares) have remained relatively constant, fluc-

tuating around 70%.

Although the evidence is lean, these findings sug-

gest that practice changed with the emersion ofnew evidence (McMahon, 1996) and a new VBAC

guideline (ACOG, 1999). We then examined the

studies for ways that practice may have changed,

for example, not allowing women with more than

oneprior cesareanor a certain type of scar to have

a TOL, reduction in either induction, or epidural

use. Many studies did not report the proportion

of women with more than one prior cesarean or

who had a certain type of scar or the proportion

who were induced or had epidurals (DiMaio, 2002;

Gregory, 1999; Gregory et al., 2008; Loebel, 2004;

Pickhardt et al., 1992; Troyer & Parisi, 1992). De-

scriptively, it appeared that studies enrolled fewer

and fewer women with more than one prior ce-

sarean over time. Studies completed before 1996

reported that 19% (Stovall, 1987) to 23% (Phe-

lan, 1987) of women with a TOL had more than

one prior cesarean. For studies launched in 1996,

between 9% (Macones et al., 2005) and 19% (De-

Franco et al., 2007) of women with a TOL hadmore than one cesarean. However, the large Na-

tional Institute of Child Health and Human Devel-

opment Maternal - Fetal Medicine Units Network

(MFMU) study launched in 1999 reported only 5%

of women had more than a single prior cesarean

(Landon et al., 2006). We did not observe a con-

sistent change over time in TOL eligibility based

on type of scar (DiMaio, 2002; Durnwald & Mer-

cer, 2004b; Flamm, 1994; Landon et al., 2006;



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Women delivering in hospitals with higher delivery volumes,

tertiary care centers, and teaching hospitals were more likely to

have a trial of labor.

Loebel, 2004; Macones et al., 2005; Phelan, 1987;Stovall, 1987; Troyer & Parisi, 1992), use of induc-

tion, (DeFranco et al., 2007; Durnwald & Mercer,

2004b; Hook, 1997; Landon et al., 2006; Phelan,

1987; Stovall, 1987) or epidural (Durnwald & Mer-

cer, 2004b; Fisler, 2003; Landon et al., 2006; Sto-

vall, 1987).

Most evidence of TOL and vaginal delivery rates

after TOL are from studies based in large tertiary

care centers and are highly variable. Because

the vaginal delivery rate has not improved with

a smaller pool of women, we sought evidence

on whether characteristics of the delivery systemor the patient contributed to the decision about

whether a TOL was offered.

What Factors Contributed to an Option

of a TOL?

Six good cohort studies (Cameron, 2004; Chang,

2008; DeFranco et al., 2007; Harper et al., 2009;

McMahon, 1996; Pang, 2009), three fair quality

cohort studies (Bujold, 2001; Hueston & Rudy,

1994; Selo-Ojeme, 2008), and one good quality

cross-sectional study (Kabir, 2005) reported fac-

tors that may have contributed to whether women

were offered a TOL. Two themes emerged fromthese studies related to site of delivery and the

woman’s history of a prior vaginal delivery.

Women delivering in hospitals with higher deliv-

ery volumes, tertiary care centers, and teaching

hospitals were more likely to have a TOL (Table 2)

(Cameron, 2004; DeFranco et al., 2007; Hueston

& Rudy, 1994; McMahon, 1996). Delivery volume

in teaching hospitals predicted TOL in one ret-

rospective cohort study conducted in 1990 and

1991, even when adjusted by race, employment,

marital status, and obstetric risk (Hueston & Rudy,

1994).

Level of care also appeared to influence the deci-

sion for a TOL (Table 2). In one study women had

an increased likelihood of TOL if they delivered

at a Level 5 or 6 hospital (metro district hospital

for high-risk mothers/babies or perinatal center)

and a decreased likelihood at a Level 4 or below

(metro district for moderate-risk mothers/babies,

rural, and private hospitals) (Cameron, 2004). In

this study of Australian deliveries during 1998 to

2001 (Cameron, 2004), predictors of TOL were

evaluated for 14,350 charts of women eligible for

TOL by the ACOG standards (1999). In a sepa-

rate study conducted in Nova Scotia, Canada, be-

tween 1986 and 1992, researchers similarly found

that women in community and regional hospitals

wereonehalf aslikely tohave a TOL aswomende-

livering in tertiary care centers (McMahon, 1996).

The presence of a residency program consistently

improved the likelihood that women were offered

TOLs (DeFranco et al., 2007; Kabir, 2005) when

compared to settings without residency programs.

In a secondary analysis of a retrospective study

(conducted in 1996–2000) (DeFranco et al., 2007)

of 17 hospitals, women delivering in hospitals that

did not have an obstetric/gynecology residency

program were less likely to have a TOL (odds ratio

[OR] = .88, CI [0.82, 0.95]) even when adjusting

for age, obstetric history, birth weight, gestational

age, and maternal risks. In another secondary

analysis of the Agency for Healthcare Research

and Quality’s (AHRQ) 2001 Healthcare Cost and

Utilization Project (HCUP) National Inpatient Sam-

ple database, investigators reported that women

had a reduced likelihood of TOL if they were deliv-

ered in rural or nonteaching urban hospitals(Kabir,

2005). These investigators identified all women

who had unnecessary RCDs (had no discharge

indication, ICD-9 code, for a cesarean) as a way

to quantify the number of women who may not

have been offered a TOL; the database includes

data from 33 states. In this study, a prior cesareanalone was not considered as sufficient justification

for a RCD. With this definition, 65% of RCDs were

considered unnecessary and overall bed size of

the hospital was not related to unnecessary RCDs.

When providers consider whether to offer the op-

tion of a TOL after a prior cesarean, careful at-

tention is given to prior obstetric history in es-

timating likelihood of VBAC. Three retrospective

cohort studies, (Cameron, 2004; McMahon, 1996;

Pang, 2009) and a secondary analysis (Harper

et al., 2009) of a large retrospective study (Ma-

cones et al., 2005) examined whether obstetricfactors such as number of prior vaginal deliv-

eries or gestational age at the prior cesarean

predicted whether women had a TOL (Table 3).

The likelihood of TOL increased (OR ranged from

1.51 to 6.67) for women with prior vaginal de-

liveries (Cameron, 2004; McMahon, 1996; Pang,

2009) whereas it decreased for women who had

a prior cesarean before 34 weeks gestational age

(Harper et al., 2009).



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DiscussionVaginal delivery rates for women who had a TOL

have remained constant over the same time pe-

riod. Since 1996, the number of women who had

a TOL at sites still offering TOLs fell to less than

one half of those eligible. Among women who had

a TOL, 74% delivered vaginally. The vaginal deliv-ery rate with TOL in this updated evidence report is

consistent with the previously reported rate (76%)

in the 2003 evidence report on VBAC (Guise et al.,

2003). The newer evidence suggests that many

women who would have delivered vaginally had

elective cesarean deliveries either by own choice

or because of barriers in the health system. It is

important to note that the TOL and vaginal deliv-

ery rates with TOL summarized in this report were

obtained from sites that still provided TOLs. Our

reported vaginal delivery rates with TOL will ex-

ceed reported national VBAC rates that include

sites that limit (or prohibit) TOLs.

With newly issued concluding consensus state-

ments, rates of TOL may again increase for stud-

Since 1996, the number of women who had a trial of labor atsites still offering this option fell to less than one half of those

eligible.

ies launched after 2010. The 2010 Consensus De-

velopment Panel on VBAC urged that barriers to

TOL be removed to again give a woman an op-

portunity to make an informed choice with her

provider: “We recommend that hospitals, mater-

nity care providers, healthcare and professional

liability insurers, consumers, and policymakers

collaborate on the development of integrated ser-

vices that could mitigate or even eliminate current

barriers to TOL” (U.S. Department of Health and

Human Services, 2010, p. 3).

Although some barriers are obvious to the patient,

for example, the hospital will not allow TOLs, ef-

forts are needed to address less obvious barriers

(to the patient), such as liability to the provider.

In a survey of ACOG fellows, 41% of the 639

Table 2: Characteristics of Delivery Sites and Likelihood of TOL

Author, Year Characteristic Adjusted Odds 95% CI

Ratio for TOL

Volume of Deliveries

Hueston & Rudy, 1994 252 women with prior CD/2y 1.00 Referent

135 women with prior CD/2y 0.46 0.29, 0.74



Hospital Level

Cameron, 2004 Level 6 (Perinatal center) 1.00 Referent

Level 5 (High-risk care) 1.22 1.09, 1.37

Level 4 (moderate-risk care) 0.90 0.81, 0.99

Level 1–3 (Rural)a 0.66 0.58, 0.74

Private 0.45 0.41, 0.50

McMahon, 1996 Tertiary care 1.00 Referent

Regional hospital 0.50 0.50, 0.60

Community hospital 0.40 0.30, 0.50

Teaching St atus

DeFranco, 2007 Obstetrics/Gynecology Residency program 1.00 Referent

No program 0.88 0.82, 0.95

Note. CD = cesarean delivery; CI = confidence interval; TOL = trial of labor; y = year(s).Adapted with permission from Guise, J. M., Eden, K., Emeis, C., Denman, M., Marshall, N., Fu, R., . . . McDonagh, M. (2010). Vaginal

birth after cesarean: New insights. Evidence report/technology assessment no. 191 (AHRQ publication no. 10-E001). Rockville, MD:Agency for Healthcare Research and Quality.a96% rural hospitals.



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Many patients may not be aware of risks and benefits or

prepared to advocate for their desired mode of delivery.

respondents cited “fear of liability” as one of many

“most important” factors to consider in advisingpatients about whether to have a TOL (Coleman

et al., 2005). Similarly, investigators of a retro-

spective cohort study (Yang, Mello, Subramanian,

& Studdert, 2009) estimated that a decrease of

$10,000 (in 2003 dollars) in the malpractice pre-

mium (equivalent to a 20%–25% average premium

decrease for OB/GYNs) would have translated to

1,600 more VBACs and 6,000 fewer cesarean de-

liveries (including 3,600 fewer primary cesarean

deliveries), nationally in 2003.

The dawn of the economic recession in 2007 may

have augmented provider and insurer rationale forlow TOL rates over the past 3 years. In a time

where most businesses are looking to cut costs

and fear of litigation remains high, changing pol-

icy to allow VBAC may be viewed as too risky

financially to implement. In addition to decreasing

TOL rates, it is important to note a striking de-

cline in the U.S. birth rate since 2007. The April

2010 Pew Research Center birth trends report

(compiled using data from the 25 states with fi-

nal 2008 birth numbers) shows that the national

U.S. birth rate grew steadily from 2003 to 2007,

then sharply declined by 2% from 2007 to 2008,

and has steadily decreased since (Livingston &Cohn, 2010). Popular media outlets, such as The

New York Times and National Public Radio have

explored this topic, noting that many women are

focusing more on contraceptive use than family

growth because they are concerned about the

cost of raising children in a down economy (As-

sociated Press, 2010; Siegal, 2010). As individ-

ual hospitals lose revenue due to declining birth

rates, it will be interesting to analyze the effect of

the 2010 Clinical Management Guidelines (ACOG,

2010) on TOL.

Nursing Implications

National guidelines on VBAC from the Royal Col-

lege of Obstetricians and Gynaecologists in the

United Kingdom and Women’s Hospital Australa-

sia (Australia) emphasize the importance of of-

fering women information so that they can dis-

cuss the childbirth options(Foureur, Ryan, Nicholl,

& Homer, 2010). Although U.S. providers report

knowing the risks and benefits of VBAC and RCD

(Coleman et al., 2005), it is not clear that manypatients are aware of such risks and benefits or

are prepared to advocate for their desired mode of

delivery. Perinatal nurses, nurse practitioners, and

certified nurse midwives are well positioned to as-

sess women’s knowledge about delivery options

and their associated risks and benefits. When

knowledge is lacking, they can provide education

and counseling to address this need.

The importance of informing patients also

emerged in the vision statement from Childbirth

Connection’s Transforming Maternity Care, a col-

laboration of 100 national leaders representing ob-stetrics, nurse-midwifery, maternity nursing, family

medicine, health policy, health economics, quality,

Table 3: Past Obstetric Factors as Predictors of Trial of Labor

Author, Year Study Design Characteristic Adjusted odds 95% CI

Ratio or Relative

Risk for VBAC

Number of Previous Vaginal Deliveries

Cameron, 2004, Retrospective Cohort 1 Prior VD 1.51 1.35, 1.68

2 Prior VDs 2.35 1.92, 2.86

≥3 Prior VDs 2.94 2.23, 3.88

McMahon, 1996, Retrospective Cohort 1 Prior VD 3.20 Not reported

2 Prior VDs 4.00 Not reported

Pang, 2009, Retrospective Cohort History of VD 6.67 2.70, 16.67

Note. CI = confidence interval; VD = vaginal delivery; VBAC = vaginal birth after cesarean.Reprinted with permission from Guise, J. M., Eden, K., Emeis, C., Denman, M., Marshall, N., Fu, R., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No. 191 (AHRQ publication no. 10-E001). Rockville, MD:Agency for Healthcare Research and Quality.



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patient safety, childbirth education, maternal fetal

medicine, and health consumer advocacy (Carter

et al., 2010). One of the guiding principles for their

2020 vision presented in April 2009 was to pro-

vide women with the opportunity to make informed

choices (Carter et al.). To make this vision a re-

ality, future work is needed in creating evidence-

based patient education products (brochures, de-

cision aids) designed using plain language so that

women feel informed and prepared to enter into a

dialog about birth choice. Additionally, future work

is needed to integrate these tools into current clini-

cal practice and may require health care providers

to adopt a shared style of decision making that

uses this new technology (Shorten, 2010). Less

than a year after the Childbirth’s Connections’ vi-

sion statement waspresented, the NIHVBAC Con-

sensus Development panel echoed the same sen-

timent but with an emphasis on shared decision

making among informed patients and providers:

“Information, including risk assessment, should be

shared withthe woman at a level and pace that she

can understand. When both TOL and ERCD are

medically equivalent options, a shared decision

making process should be adopted and, when-

ever possible, the woman’s preference should be

honored” (U.S. Department of Health and Human

Services, 2010, p. 33).

AcknowledgmentBased on a systematic evidence review con-

ducted for and presented to the National Institutes

of Health Consensus Development Conferenceon Vaginal Birth After Cesarean: New Insights.

Funded by the Agency for Healthcare Research

and Quality (AHRQ), Contract No. HHSA 290-

2007-10057-I, Task Order No. 4 for the Office of

Medical Applications of Research at the National

Institutes of Health. The findings and conclusions

in this document are those of the authors, who are

responsible for its content, and do not necessarily

represent the views of AHRQ. No statement in this

report should be construed as an official position

of AHRQ or of the U.S. Department of Health and

Human Services.

REFERENCESAmerican College of Obstetricians and Gynecologists. (1999). ACOG

practice bulletin. Vaginal birth after previous cesarean delivery.

Number 5, July 1999 (replaces practice bulletin number 2, Oc-

tober 1998). Clinical management guidelines for obstetrician-

gynecologists. American College of Obstetricians and Gynecol-

ogists. (1999). International Journal of Gynaecology & Obstet-

rics , 66 (2), 197–204.

American College of Obstetricians and Gynecologists. (2010). ACOG

practice bulletin no. 115: Vaginal birth after previous ce-

sarean delivery. Obstetrics & Gynecology , 116 (2, Part 1), 450–

463.

Associated Press. (August 28, 2010). Birthrate is lowest in a century.

The New York Times, A11.

Bais, J. M., van der Borden, D. M., Pel, M., Bonsel, G. J., Eskes, M.,

van der Slikke, H. J., & Bleker, O. P. (2001). Vaginal birth after

caesarean section in a population with a low overall caesarean

section rate. European Journal of Obstetrics, Gynecology, & Re-

productive Biology , 96 (2), 158–162.

Bujold, E., & Gauthier, R. J. (2001). Should we allow a trial of labor after

a previous cesarean for dystocia the second stage of labor?


Cameron, C. A., Roberts, C. L., & Peat, B. (2004). Predictors of labor

and vaginal birth after cesarean section. International Journal of

Gynaecology & Obstetrics , 85 (3), 267–269.

Carter, M., Corry, M., Delbanco, S., Foster, T., Friedland, R., Gabel,

R., . . . Simpson, K. R. (2010). 2020 vision for a high-quality,

high-value maternity care system. Women’s Health Issues , 20 (1

Suppl), S7–17.

Caughey, A. B., Shipp, T. D., Repke, J. T., Zelop, C. M., Cohen, A.,

& Lieberman, E. (1999). Rate of uterine rupture during a trial

of labor in women with one or two prior cesarean deliveries.

American Journal of Obstetrics & Gynecology , 181(4), 872–

876.

Chang, J. J., Stamilio, D. M., & Macones, G. A. (2008). Effect of hospi-

tal volume on maternal outcomes in women with prior cesarean

delivery undergoing trial of labor. American Journal of Epidemi-

ology , 167 (6), 711–718.

Coleman, V. H., Erickson, K., Schulkin, J., Zinberg, S., & Sachs, B. P.

(2005). Vaginal birthafter cesarean delivery: Practice patterns of

obstetrician-gynecologists. Journal of Reproductive Medicine ,

50 (4), 261–266.

Costantine, M. M., Fox, K., Byers, B. D., Materus, J., Ghulmiyyah, L.

M., Blackwell, S., . . . Saade, G. (2009). Validation of the predic-

tion model for success of vaginal birth after cesarean delivery.


DeFranco, E. A., Rampersad, R., Atkins, K. L., Odibo, A. O., Stevens,

E. J., Peipert, J. F., . . . Macones, G. A. (2007). Do vaginal birth

after cesarean outcomes differ based on hospital setting? Amer-

ican Journal of Obstetrics & Gynecology , 197 (4), 400.e401–

406.

Delaney, T., & Young, D. C. (2003). Spontaneous versus induced labor

after a previous cesarean delivery. Obstetrics & Gynecology ,

102 (1), 39–44.

DerSimonian, R., & Laird, N. (1986). Meta-analysis in clinical trials.

Controlled Clinical Trials , 7 (3), 177–188.

DiMaio, H., Edwards, R. K., Euliano, T. Y., Treloar, R. W., & Cruz, A. C.

(2002). Vaginal birth after cesarean delivery: An historic cohort

cost analysis. American Journal of Obstetrics & Gynecology ,

186 (5), 890–892.

Dinsmoor, M. J.,& Brock, E.L. (2004).Predictingfailedtrial oflabor after

primary cesarean delivery. Obstetrics & Gynecology , 103 (2),

282–286.

Durnwald, C. P., Ehrenberg, H. M., & Mercer, B. M. (2004a). The im-

pact of maternal obesity and weight gain on vaginal birth after

cesarean section success. American Journal of Obstetrics &

Gynecology , 191(3), 954–957.

Durnwald, C. P., & Mercer, B. (2004b). Vaginal birth after Cesarean

delivery: Predictingsuccess,risks of failure. Journal of Maternal-

Fetal & Neonatal Medicine , 15 (6), 388–393.

Eden, K. B., McDonagh, M., Denman, M. A., Marshall, N., Emeis, C.,

Fu, R., . . . Guise, J. M. (2010). New insights on vaginal birth

after cesarean, can it be predicted? Obstetrics & Genecology ,

116 (4), 967–981.



14/16


El-Sayed, Y. Y., Watkins, M. M., Fix, M., Druzin, M. L., Pullen, K. M., &

Caughey, A. B. (2007). Perinatal outcomes after successful and

failed trials of labor after cesarean delivery. American Journal

of Obstetrics & Gynecology , 196 (6), 583.e581–585; discussion

583.e585.

Elkousy, M. A., Sammel, M., Stevens, E., Peipert, J. F., & Macones,

G. (2003). The effect of birth weight on vaginal birth after

cesareandelivery success rates.AmericanJournal of Obstetrics

& Gynecology , 188 (3), 824–830.

Fisler, R. E., Cohen, A., Ringer, S. A., & Lieberman, E. (2003). Neona-

tal outcome after trial of labor compared with elective repeat

cesarean section. Birth , 30 (2), 83–88.

Flamm, B. L., Goings, J. R., Fuelberth, N. J., Fischermann, E., Jones,

C., & Hersh, E. (1987). Oxytocin during labor after previous ce-

sarean section: Results of a multicenter study. Obstetrics & Gy-

necology , 70 (5), 709–712.

Flamm, B. L., Goings, J. R., Liu, Y., & Wolde-Tsadik, G. (1994). Elec-

tive repeat cesarean delivery versus trial of labor: A prospec-

tive multicenter study. Obstetrics & Gynecology , 83 (6), 927–

932.

Foureur, M., Ryan, C. L., Nicholl, M., & Homer, C. (2010). Inconsistent

evidence: Analysis of six national guidelines for vaginal birth

after cesarean section. Birth , 37 (1), 3–10.

Gonen, R., Nisenblat, V., Barak, S., Tamir, A., & Ohel, G. (2006). Results

of a well-defined protocol for a trial of labor after prior cesarean

delivery. Obstetrics & Gynecology , 107 (2 Pt 1), 240–245.

Goodall, P. T., Ahn, J. T., Chapa, J. B., & Hibbard, J. U. (2005). Obesity

as a risk factorforfailed trial oflaborin patients with previous ce-

sarean delivery. American Journal of Obstetrics & Gynecology ,

192 (5), 1423–1426.

Gregory, K. D., Korst, L. M., Cane, P., Platt, L. D., & Kahn, K. (1999).

Vaginal birth after cesarean and uterine rupture rates in Califor-

nia. Obstetrics & Gynecology , 94 (6), 985–989.

Gregory, K.D., Korst, L. M.,Fridman,M., Shihady,I., Broussard,P., Fink,

A., . . . Burnes Bolton, L. (2008). Vaginal birth after cesarean:

Clinical risk factors associated with adverse outcome. Ameri-

can Journal of Obstetrics & Gynecology , 198 (4), 452.e451–410;

discussion 452.e410–452.

Guise,J. M.,Denman,M.,Emeis, C.,Marshall,N.,Walker,M.,Fu, R., . . .

McDonagh,M. (2010). Vaginalbirth after cesarean:New insights

on maternal and neonatal outcomes. Obstetrics & Gynecology ,

115 (6), 1267–1278.

Guise, J. M., Eden, K., Emeis, C., Denman, M., Marshall, N., Fu, R.,

. . . McDonagh, M. (2010). Vaginal birth after cesarean: New in-

sights. Evidence report/technology assessment No. 191 (AHRQ

Publication No. 10-E001) . Rockville, MD: Agency for Healthcare

Research and Quality.

Guise, J. M., McDonagh, M. S., Hashima, J., Kraemer, D. F., Eden,

K. B., Berlin, M., . . . Helfand, M. (2003). Vaginal birth after ce-

sarean (VBAC). Evidence report: Technology assessment No.

71 (AHRQ Publication No. 03-E018) . Rockville, MD: Agency for

Healthcare Research and Quality.

Gyamfi,C., Juhasz, G.,Gyamfi, P.,& Stone,J. L.(2004).Increased suc-

cess of trial of labor after previous vaginal birth after cesarean.


Hammoud, A., Hendler, I., Gauthier, R. J., Berman, S., Sansregret, A.,

& Bujold, E. (2004). The effect of gestational age on trial of la-

bor after cesarean section. Journal of Maternal-Fetal & Neonatal

Medicine , 15 (3), 202–206.

Harper, L. M., Cahill, A. G., Stamilio, D. M., Odibo, A. O., Peipert, J. F.,

& Macones, G. A. (2009). Effect of gestational age at the prior

cesarean delivery on maternal morbidity in subsequent VBAC

attempt. American Journal of Obstetrics & Gynecology , 200 (3),

276.e271–276.

Harris, R. P., Helfand, M., Woolf, S. H., Lohr, K. N., Mulrow, C. D.,

Teutsch, S. M., & Atkins, D. (2001). Current methods of the U.S.

Preventive Services Task Force: A review of the process. Ameri-

can Journal of Preventive Medicine , 20 (3, Suppl 1), 21–35.

Hashima, J. N., & Guise, J. M. (2007). Vaginal birth after cesarean: A

prenatal scoring tool. American Journal of Obstetrics & Gyne-

cology , 196 (5), e22–23.

Healthy Inclusion. (2001). Undertaking systematic reviews of re-

search on effectiveness: CRD’s guidance for those carry-

ing out or commissioning reviews . Retrieved from http://www.

healthy-inclusion.org.uk/

Hendler, I., & Bujold, E. (2004). Effect of prior vaginal delivery or

prior vaginal birth after cesarean delivery on obstetric outcomes

in women undergoing trial of labor. Obstetrics & Gynecology ,

104 (2), 273–277.

Hibbard, J. U., Gilbert, S., Landon, M. B., Hauth, J. C., Leveno, K.

J., Spong, C. Y., . . . Gabbe, S. G. (2006). Trial of labor or re-

peat cesarean delivery in women with morbid obesity and pre-

vious cesarean delivery. Obstetrics & Gynecology , 108 (1), 125–

133.

Higgins, J. P., Thompson, S. G., Deeks, J. J., & Altman, D. G. (2003).

Measuring inconsistency in meta-analyses. British Medical Jour-

nal , 327 (7414), 557–560.

Higgins, J. P., Thompson, S. G., Higgins, J. P. T., & Thompson, S. G.

(2002). Quantifying heterogeneity in a meta-analysis. Statistics

in Medicine , 21(11), 1539–1558.

Hollard, A. L., Wing, D. A., Chung, J. H., Rumney, P. J., Saul, L., Na-

geotte, M.P.,& LagrewD. (2006). Ethnicdisparity in thesuccess

of vaginal birth after cesarean delivery. Journal of Maternal-Fetal

& Neonatal Medicine , 19 (8), 483–487.

Hook,B.,Kiwi,R.,Amini, S.B.,Fanaroff,A.,& Hack,M. (1997). Neonatal

morbidityafter electiverepeatcesareansectionand trialof labor.

Pediatrics , 100 (3 Pt 1), 348–353.

Horenstein, J. M., Eglinton, G. S., Tahilramaney, M. P., Boucher, M.,

& Phelan, J. P. (1984). Oxytocin use during a trial of labor in

patientswith previous cesareansection. Journal of Reproductive

Medicine , 29 (1), 26–30.

Horenstein, J. M.,& Phelan, J. P. (1985). Previous cesarean section:The

risks and benefits of oxytocin usage in a trial of labor. American

Journal of Obstetrics & Gynecology , 151(5), 564–569.

Hoskins, I. A., & Gomez, J. L. (1997). Correlation between maximum

cervical dilatation at cesarean delivery and subsequent vaginal

birth after cesarean delivery. Obstetrics & Gynecology , 89 (4),

591–593.

Huang, W. H., Nakashima, D. K., Rumney, P. J., Keegan, K. A. Jr., &

Chan,K. (2002). Interdelivery interval and thesuccess of vaginal

birth after cesarean delivery. Obstetrics & Gynecology , 99 (1),

41–44.

Hueston, W. J., & Rudy, M. (1994). Factors predicting elective repeat

cesarean delivery. Obstetrics & Gynecology , 83 (5 Pt 1), 741–

744.

Jakobi, P., Weissman, A., Peretz, B. A., & Hocherman, I. (1993). Eval-

uation of prognostic factors for vaginal delivery after cesarean

section. Journal of Reproductive Medicine , 38 (9), 729–733.

Johnson, C., Oriol, N., & Flood, K. (1991). Trial of labor: A study of 110

patients. Journal of Clinical Anesthesia , 3 (3), 216–218; discus-

sion 214–215.

Juhasz, G., Gyamfi, C., Gyamfi, P., Tocce, K., & Stone, J. L. (2005). Ef-

fect of body mass index and excessive weight gain on success

of vaginal birth after cesarean delivery. Obstetrics & Gynecol-

ogy , 106 (4), 741–746.

Kabir, A. A., Pridjian, G., Steinmann, W. C., Herrera, E. A., & Khan,

M. M. (2005). Racial differences in cesareans: An analysis of

U.S. 2001 National Inpatient Sample Data [Erratum appears in



15/16


Obstet Gynecol. 2005 Jun;105(6):1495]. Obstetrics & Gynecol-

ogy , 105 (4), 710–718.

Kugler, E., Shoham-Vardi, I., Burstien, E., Mazor, M., & Hershkovitz,

R. (2008). The safety of a trial of labor after cesarean section

in a grandmultiparous population. Archives of Gynecology &

Obstetrics , 277 (4), 339–344.

Landon, M.B., Spong,C. Y.,Thom,E.,Hauth,J. C.,Bloom,S. L.,Varner,

M. W., . . . Gabbe, S. G. (2006). Risk of uterine rupture with a

trial of labor in women with multiple and single prior cesarean

delivery. Obstetrics & Gynecology , 108 (1), 12–20.

Learman, L. A., Evertson, L. R., & Shiboski, S. (1996). Predictors of

repeatcesarean delivery aftertrialof labor:do anyexist? Journal

of the American College of Surgeons , 182 (3), 257–262.

Lieberman, E., Ernst, E. K., Rooks, J. P., Stapleton, S., & Flamm, B.

(2004). Results of the national study of vaginal birth after ce-

sarean in birth centers. Obstetrics & Gynecology , 104 (5 Pt 1),

933–942.

Livingston, G., & Cohn, D. V. (2010). U.S. birth rate decline linked

to recession . Washington, DC: Pew Research Center. Re-

trieved January 19, 2012, from http://pewsocialtrends.org/files/

2010/10/753-birth-rates-recession.pdf

Locatelli, A., Regalia, A. L., Ghidini, A., Ciriello, E., Biffi, A., & Pezzullo,

J. C. (2004). Risks of induction of labour in women with a uterine

scar from previous low transverse caesarean section. BJOG:

An International Journal of Obstetrics & Gynaecology , 111(12),

1394–1399.

Loebel, G., Zelop, C. M., Egan, J. F. X., & Wax, J. (2004). Maternal

and neonatal morbidity after elective repeat cesarean delivery

versus a trial of labor after previous cesarean delivery in a com-

munity teaching hospital. Journal of Maternal-Fetal & Neonatal

Medicine , 15 (4), 243–246.

Macones, G. A., Peipert, J., Nelson, D. B., Odibo, A., Stevens, E. J.,

Stamilio,D. M., . . . Ratcliffe,S. J. (2005).Maternalcomplications

with vaginal birth after cesarean delivery: a multicenter study.

American Journal of Obstetrics & Gynecology , 193 (5), 1656–

1662.

Martin, J. A., Hamilton, B. E., Sutton, P. D., Ventura, S. J., Mathews, T.

J., Kirmeyer, S., & Osterman, M. J. (2010). Births: Final data for

2007. National Vital Statistics Reports , 58 (24), 1–85.

McMahon, M. J., Luther, E. R., Bowes, W. A. Jr., & Olshan, A. F. (1996).

Comparison of a trial of labor with an elective second cesarean

section. New England Journal of Medicine , 335 (10), 689–695.

McNally, O. M., & Turner, M. J. (1999). Induction of labour after 1

previous caesarean section. Australian & New Zealand Journal

of Obstetrics & Gynaecology , 39 (4), 425–429.

Menacker, F., Declercq, E., & Macdorman, M. F. (2006). Cesarean de-

livery: Background, trends, and epidemiology. Seminars in Peri-

natology , 30 (5), 235–241.

Nguyen, T. V., Dinh, T. V., Suresh, M. S., Kinch, R. A., & Anderson, G.

D. (1992). Vaginal birth after cesarean section at the University

of Texas. Journal of Reproductive Medicine , 37 (10), 880–882.

Obara, H., Minakami, H., Koike, T., Takamizawa, S., Matsubara, S.,

& Sato, I. (1998). Vaginal birth after cesarean delivery: Results

in 310 pregnancies. Journal of Obstetrics & Gynaecology Re-

search , 24 (2), 129–134.

Ouzounian, J. G., Miller, D. A., & Paul, R. H. (1996). Amnioinfusion

in women with previous cesarean births: A preliminary report.

American Journal of Obstetrics & Gynecology , 174 (2), 783–786.

Pang, M. W., Law, L. W., Leung, T. Y., Lai, P. Y., & La, T. K. (2009).

Sociodemographic factors and pregnancy events associated

with women who declined vaginal birth after cesarean section.

European Journal of Obstetrics, Gynecology, & Reproductive

Biology , 143 (1), 24–28.

Pathadey, S. D., Van Woerden, H. C., & Jenkinson, S. D. (2005). Induc-

tionof labour after a previous caesareansection:A retrospective

study in a district general hospital. Journal of Obstetrics & Gy-

naecology , 25 (7), 662–665.

Phelan, J. P., Clark, S. L., Diaz, F., & Paul, R. H. (1987). Vaginal birth

after cesarean. American Journal of Obstetrics & Gynecology ,

157 (6), 1510–1515.

Pickhardt, M. G., Martin, J. N. Jr., Meydrech, E. F., Blake, P. G., Martin,

R. W., Perry, K. G. Jr., & Morrison, J. C. (1992). Vaginal birth after

cesarean delivery: Are there useful and valid predictors of suc-

cess or failure? American Journal of Obstetrics & Gynecology ,

166 (6 Pt 1), 1811–1815; discussion 1815–1819.

Raynor, B. D. (1993). The experience with vaginal birth after cesarean

delivery in a small rural community practice. American Journal

of Obstetrics & Gynecology , 168 (1 Pt 1), 60–62.

Rozenberg, P., Goffinet, F., Phillippe, H. J., & Nisand, I. (1996). Ultra-

sonographic measurement of lower uterine segment to assess

risk of defects of scarred uterus. Lancet , 347 (8997), 281–284.

Rozenberg,P.,Goffinet,F.,Philippe,H. J.,& Nisand, I.(1999).Thickness

of the lower uterine segment: Its influence in the management of

patients with previous cesarean sections. European Journal of

Obstetrics, Gynecology, & Reproductive Biology , 87 (1), 39–45.

Sakala, E. P., Kaye, S., Murray, R. D., & Munson, L. J. (1990). Oxytocin

use after previous cesarean: Why a higher rate of failed labor

trial? Obstetrics & Gynecology , 75 (3 Pt 1), 356–359.

Scott, J. R. (2010). Solving the vaginal birth after cesarean dilemma.


Selo-Ojeme,D., Abulhassan,N., Mandal, R.,Tirlapur,S., & Selo-Ojeme,

U. (2008). Preferredand actual delivery modeafter a cesareanin

London, UK. International Journal of Gynaecology & Obstetrics ,

102 (2), 156–159.

Shorten, A. (2010). Bridging the gap between mothers and medicine:

“New Insights” from the NIH Consensus Conference on VBAC.

Birth , 37 (3), 181–183.

Siegal, R. (Narrator). (2010, August 25). Birth rates drop amid falter-

ing economy [Radio broadcast]. In M. Martinez (Producer), All

things considered . Washington, DC: National Public Radio.

Smith, G. C. S., Pell, J. P., Cameron, A. D., & Dobbie, R. (2002).

Risk of perinatal death associated with labor after previous ce-

sarean delivery in uncomplicated term pregnancies. Journal of

the American Medical Association , 287 (20), 2684–2690.

Smith, G. C. S., White, I. R., Pell, J. P., & Dobbie, R. (2005). Predicting

cesarean section and uterine rupture among women attempting

vaginal birth after prior cesarean section.[see comment]. PLoS

Medicine/Public Library of Science , 2 (9), e252, 871–878.

Socol, M. L., & Peaceman, A. M. (1999). Vaginal birth after cesarean:

An appraisal of fetal risk. Obstetrics & Gynecology , 93 (5 Pt 1),

674–679.

Spaans, W. A., Sluijs, M. B., van Roosmalen, J., & Bleker, O. P. (2002).

Risk factors at caesarean section and failure of subsequent trial

of labour. European Journal of Obstetrics, Gynecology, & Re-

productive Biology , 100 (2), 163–166.

Stovall, T. G., Shaver, D. C., Solomon, S. K., & Anderson, G. D. (1987).

Trial of labor in previous cesarean section patients, excluding

classical cesarean sections. Obstetrics & Gynecology , 70 (5),

713–717.

Strong, J. M.,& McQuillan,K. (1996). Factors affecting mode of delivery

in labour following a single previous birth by cesarean. Journal

of Obstetrics & Gynaecology , 16 (5), 353–357.

Sutton, A. J., Abrams, K. R., Jones, D. R., Sheldon, T. A., & Song,

F. (2000). Methods for meta-analysis in medical research . New

York, NY: John Wiley & Sons.

Thompson, S. G., & Sharp, S. J. (1999). Explaining heterogeneity in

meta-analysis: A comparison of methods. Statistics in Medicine ,

18 (20), 2693–2708.



16/16


Troyer, L. R., & Parisi, V. M. (1992). Obstetric parameters affecting suc-

cess ina trialof labor:Designation ofa scoring system.American

Journal of Obstetrics & Gynecology , 167 (4 Pt 1), 1099–1104.

U.S. Department of Health and Human Services. National Insti-

tutes of Health. (2010). NIH consensus development confer-

ence statement: Vaginal birth after cesarean: New insights.

March 8–10, 2010 . Retrieved from http://consensus.nih.gov/

2010/images/vbac/vbac_statement.pdf

van Gelderen, C. J., England, M. J., Naylor, G. A., & Katzeff, T. C.

(1986). Labour in patients with a caesarean section scar. The

place of oxytocin augmentation. South African Medical Journal

Suid-Afrikaanse Tydskrif Vir Geneeskunde , 70 (9), 529–532.

Vinueza, C. A., Chauhan, S. P., Barker, L., Hendrix, N. W., & Scardo, J.

A. (2000). Predicting the success of a trial of labor with a simple

scoring system. Journal of Reproductive Medicine , 45 (4), 332–

336.

Weinstein, D.,Benshushan, A., Tanos, V., Zilberstein, R., & Rojansky, N.

(1996). Predictive score for vaginal birth after cesarean section.

American Journal of Obstetrics & Gynecology , 174 (1 Pt 1), 192–

198.

Wen, S. W., Rusen, I. D., Walker, M., Liston, R., Kramer, M. S., Bas-

kett, T., . . . Maternal Health Study Group, Canadian Perinatal

Surveillance System. (2004). Comparison of maternal mortality

and morbidity between trial of labor and elective cesarean sec-

tion among women with previous cesarean delivery. American

Journal of Obstetrics & Gynecology , 191(4), 1263–1269.

The world factbook . (2008). Washington, DC: Central Intelligence

Agency.

Yang, Y. T., Mello, M. M., Subramanian, S. V., & Studdert, D. M. (2009).

Relationship between malpractice litigation pressure and rates

of cesarean section and vaginal birth after cesarean section.

Medical Care , 47 (2), 234–242.

Yetman,T.J., & Nolan, T. E. (1989). Vaginal birthafter cesarean section:

A reappraisal of risk. American Journal of Obstetrics & Gynecol-

ogy , 161(5), 1119–1123.

Yogev, Y., Ben-Haroush, A., Lahav, E., H orowitz, E., Hod, M., & Kaplan,

B. (2004). Induction of labor with prostaglandin E2 in women

with previous cesarean section and unfavorable cervix. Euro-

pean Journal of Obstetrics, Gynecology, & Reproductive Biol-

ogy , 116 (2), 173–176.

Zelop, C. M., Shipp, T. D., Cohen, A., Repke, J. T., & Lieberman,

E. (2001). Trial of labor after 40 weeks’ gestation in women

with prior cesarean. Obstetrics & Gynecology , 97 (3), 391–

393.

Zweifler,J., Garza,A., Hughes, S.,Stanich, M.A., Hierholzer, A.,& Lau,

M. (2006). Vaginal birth after cesarean in California: Before and

after a change in guidelines. Annals of Family Medicine , 4 (3),

228–234.

598 JOGNN 41 583-598; 2012 DOI: 10 1111/j 1552- 6909 2012 01388 x http://jognn awhonn org

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Trial of Labor and Vaginal Delivery Rates in Women with Prev CS