CSections and VBACs Past, Present, and Future

1
C-Sections and VBACs Past, Present, and Future

• Russell S. Kirby, PhD, MS, FACE
• Professor and Vice Chair
• Department of Maternal and Child Health
• School of Public Health
• University of Alabama at Birmingham

2
Objectives

• Identify trends in Cesarean delivery and VBAC
• Discuss the clinical and public health
  significance of recent trends
• Describe evidence-based practice and its role in
  clinical decision making
• Review several recent influential publications
  and their impact
• Speculate on the future of obstetrics and
  labor/delivery management

3
Brief Summary for Those Who Are Knitting, Doing
Crossword Puzzles, or Discerning the Geometric
Pattern in the Carpeting

• Since the mid-1990s, both the total C-section
  rate and the VBAC rate have risen dramatically,
  both nationally and in Wisconsin.
• Although the reasons for these trends are many,
  changes in clinical management, patient
  preferences, and defensive medicine all may be
  playing a role.
• These trends should be concerning from both the
  clinical and public health perspectives.
• Hidden within the recent trends is a parable
  about the practice of evidence-based practice.

4
Trends in Cesarean Deliveries and VBACs, United
States 1990-2002
30.0
25.0
20.0
Percent of Live Births
15.0
Total C- Section
10.0
Rate
Primary C-Section
Rate
5.0
VBAC Rate
0.0
1989
1990
1991
1993
1994
1995
1996
1997
1998
1999
1992
2000
2001
2002
Year
5
Trends

• The velocity of the increase in the primary
  Cesarean section rate and the decline in VBAC
  rates in the past three years is unprecedented.
• In less than five years, more than ten years of
  increasing VBAC rates has disappeared.
• Is this a good thing, or even a matter of concern?

6
Is this a public health concern?

• Con public health does not focus on clinical
  management of patients. That is in the
  responsibility of the health care system, peer
  review, quality compliance, and provider
  organizations.
• Pro Cesarean section is among the most common
  surgical procedures. It is more expensive per
  total hospital stay than vaginal delivery, and
  leads to more complications and
  re-hospitalizations.

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Is this a public health concern?(continued)

• The Public Health Service has established goals
  for the year 2010 promoting continued reduction
  in overall Cesarean section rates and increases
  in VBAC rates for the United States.
• Objective 16-9a Reduce C-S among low-risk
  nulliparous women
• Objective 16-9b Reduce C-S among women with
  prior Cesarean birth

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Where does Wisconsin fit in?

• Historically, Wisconsin has had one of the lowest
  C-section rates in the US.
• In 1960, the rate was 4, and from the 1970s on
  the C-section rate has tended to be 25-33 lower
  than the national rate.
• Wisconsin has also been a leader in the use of
  vaginal birth after Cesarean section.

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Total Cesarean Section Rate and VBAC Rateby Race
of Mother, 2001United States Compared to
Wisconsin and Alabama
US
Wisconsin
Alabama
Rate
State Rank
Rate
Rate
State Rank
Total C-Section Rate
24.4
19.1
45th highest
27.6
4th highest
White Non-Hispanic
24.5
19.7
28.5
Black Non-Hispanic
25.9
16.9
26.8
Hispanic
23.6
18.4
21.5
VBAC Rate
16.4
11.8
6th lowest
23.0
43rd lowest
White Non-Hispanic
16.8
22.3
11.0
Black Non-Hispanic
16.7
28.8
13.5
Hispanic
14.7
22.9
12.3
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Risk Factors Associated with Cesarean Delivery

• Many patient, health care system, and physician
  characteristics are associated with higher or
  lower rates of Cesarean section.
• A partial list includes maternal age (increased
  risk), parity (decreased risk), obesity and short
  stature (increased risk), estimated fetal weight
  gt 4000g (increased risk), breech presentation
  (increased risk), delivery in teaching hospital
  (decreased risk), private insurance (increased
  risk), fear of malpractice suits (greatly
  increased risk).

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Method of Delivery by Body Mass Index
(BMI)Sinai Samaritan CNM Patients, 1994-1998

• BMI Cesarean Vaginal Total
• No. No. No.
• lt 20 9 3.2 271 97.1 279 15
• 20 - 24.9 31 3.9 759 96.1 790 42
• 25 - 25.9 28 6.5 407 93.8 434 23
• 30 28 7.4 348 92.6 376 20
• Total 96 5.1 1785 94.9 1881
• Chi-Square (3 df) 10.19, plt0.018

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Univariate Odds of Cesarean Delivery, SSMC CNM
Patients, 1994-98

• Variable Odds Ratio 95 C.I. p-value
• Primigravida 1.53 1.02, 2.28 0.038
• First Live Birth 2.69 1.75, 4.14 0.001
• Married 0.83 0.38, 1.82 0.646
• Maternal Race
• Black 0.95 0.54, 1.69 0.871
• White reference
• Hispanic 0.90 0.34, 2.38 0.835
• Other 0.71 0.09, 5.60 0.744

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Univariate Odds of Cesarean Delivery, SSMC CNM
Patients, 1994-98

• Variable Odds Ratio 95 C.I.
  p-value
• Maternal Age
• lt 15 1.19 0.27, 5.17 0.815
• 15-17 1.36 0.75, 2.47 0.305
• 18-19 1.37 0.78, 2.40 0.275
• 20-24 reference
• 25-29 1.64 0.85, 3.15 0.142
• 30-34 1.15 0.39, 3.35 0.800
• 35 3.61 1.31, 9.93 0.013

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Univariate Odds of Cesarean Delivery, SSMC CNM
Patients, 1994-98

• Variable Odds Ratio 95 C.I. p-value
• Body Mass Index
• lt 20 0.81 0.38, 1.73 0.591
• 20-24.9 reference
• 25-29.9 1.68 1.00, 2.85 0.052
• 30 1.97 1.16, 3.34 0.012
• Maternal Ht.
• lt155 cm 2.45 1.41, 4.26 0.001
• Mother Smoked 0.75 0.43, 1.30 0.302

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Adjusted Odds of Cesarean Delivery,
SSMC CNM Patients, 1994-1998
Odds Ratio
95 C.I.
p-value
Characteristic
Obesity (BMI 30 )
3.26
(1.60, 6.67)
0.0012
Weight Gain gt Recommended
2.09
(1.06, 4.11)
0.0326
Short Stature (lt 155 cm)
2.52
(1.12, 5.64)
0.0252
No Previous Live Births
4.30
(1.78, 10.37)
0.0012
Age 35
4.93
(1.08, 22.61)
0.0399
Failure to Progress
60.42
(29.86, 122.24)
0.0001
Breech Presentation
458.34
(133.74, 999)
0.0001
Placental Abruption
82.56
(19.00, 358.67)
0.0001
Fetal Distress
5.71
(2.58, 12.64)
0.0001
Severe Pre-eclampsia
8.68
(1.09, 69.20)
0.0412
Adjusted for race of mother (black), marital
status, primigravidity and very low birth
weight. Source Kaiser and Kirby Ob Gyn 2001.
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Clinical Documentation of Previous Cesarean
Section

• Most clinicians practice in settings that do not
  have comprehensive, unified clinical informatics
  applications.
• In a patient whos previous delivery was with
  another provider, how likely is it that the
  patients history will document the type of
  incision, the position of the uterine scar,
  whether single- or double-suturing was used, etc?

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Are physicians who are more likely to perform
operative vaginal deliveries more or less likely
to deliver by Cesarean section?
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Answer Yes, more likely

• Two studies demonstrate this convincingly
• 1) Sandmire and DeMott Am J Ob Gyn
  19961741557-64
• In a population-based study in Green Bay,
  physicians who had lower C-S rates had lower
  operative vaginal delivery rates.
• These physicians also had lower rates of use of
  epidurals, and lower rates of induction.
• In contrast, they had higher rates of ambulation
  during labor, and greater use of fetal heart rate
  monitoring.

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Operative Vaginal vs. C-Section Rates
(continued)

• 2) Webb, Culhane, Tolosa 2003 (unpublished Mss)
• The method of delivery was analyzed for all
  physicians with more than 100 deliveries in the
  Philadelphia metropolitan area.
• The individual physician odds ratio for use of
  vacuum/forceps was calculated, controlling for
  patient demographic and reproductive health
  characteristics.
• The odds ratios were plotted against the
  individual physician C-section rate

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Figure 1 Relationship Between Physician
Vacuum/Forceps Use and Cesarean Section Rates
Physician C Section Rate
Least Squares Regression R2 .23 F1,28 8.2
, p lt.01
Adjusted Odd Ratio for Physician Vacuum/Forceps
Use
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The Realistic Evidence-Based Rating Scale

• Class 0 Things I believe
• Class 0aThings I believe despite the available
  data
• Class 1 Randomized controlled clinical trials
  that agree with what I believe
• Class 2 Other prospectively collected data
• Class 3 Expert opinion
• Class 4 Randomized controlled clinical trials
  that dont agree with what I believe
• Class 5 What you believe that I dont

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The Practice of Evidence-based Practice

• integrating individual clinical expertise with
  the best available external clinical evidence
  from systematic research
• individual clinical expertise the proficiency
  and judgment acquired through experience and
  practice in clinical settings
• external clinical evidence clinically relevant
  research, from basic medical science and
  patient-centered clinical research

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How Do We Practice EBP?

• EBP is a life-long process of self-directed
  learning, in which caring for patients creates
  for the clinician a need for clinically important
  information about diagnosis, therapy, prognosis,
  and other clinical and health services issues.
  In this process, we
• Convert information needs into answerable
  questions (testable hypotheses)
• Track down the best evidence with which to answer
  them
• Critically appraise the evidence for validity and
  usefulness
• Apply the results of this appraisal in clinical
  practice
• Evaluate performance

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Why EBP?

• New types of evidence are being generated which,
  when known and understood, have the potential to
  create frequent and major changes in the way we
  care for our patients
• Although we need this evidence daily, we usually
  fail to get it
• Because of this, both our up-to-date knowledge
  and clinical performance deteriorate over time
• Trying to remedy this personally through
  traditional CME/CEU programs generally doesnt
  improve clinical performance
• A different approach to clinical learning has
  been shown to keep its practitioners up-to-date.
  EBP is that different approach.

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Quality of Evidence

• I Evidence obtained from at least one properly
  randomized controlled trial.
• II-1 Evidence obtained from well-designed
  controlled trials without randomization.
• II-2 Evidence obtained from well-designed cohort
  or case-control analytic studies, preferably from
  more than one center or research group.
• II-3 Evidence obtained from multiple time series
  with or without the intervention. Dramatic
  results in uncontrolled experiments (i.e. results
  of introduction of penicillin treatment in 1940s)
  could also be regarded as this type of evidence.
• III Opinions of well-respected authorities,
  based on clinical experience descriptive studies
  and case reports or reports of expert
  committees.

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Key Publications Influencing Obstetrical
Management of Labor and Delivery

• Three publications in the past four years have or
  will exert vast influence on physician management
  of labor and delivery
• Sachs BP, et al. NEJM 199934054-57.
• Greene MF. NEJM 200134554-55 (editorial
  elaborating on Lydon-Rochelle M, et al. NEJM
  20013453-8.
• Minkoff H, Chervenak FA. NEJM 2003348946-50.

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Sachs et al. on The risks of lowering the
Cesarean-delivery rate

• Argued that there is no basis for a national
  public health goal targeting a C-section rate of
  15 (or any other level).
• Recommended that trials of labor not be mandated
  for women with prior Cesarean deliveries, and not
  be conducted at all in facilities unable to
  perform emergency Cesarean delivery.

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Greene on Vaginal delivery after Cesarean
section is the risk acceptable?

• Editorializes on Lydon-Rochelle et al., opining
  that the risks of uterine rupture associated with
  VBAC are so great that physicians should counsel
  all patients with previous Cesareans concerning
  these risks and obtain informed consent before
  undergoing trial of labor.
• Do we have randomized studies on this question?

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A Look Inside

• Lydon-Rochelle et al. conducted a
  population-based, retrospective study using
  linked hospital discharge and vital statistics
  data.
• There are issues with documentation of risk
  factors and outcomes in both vital statistics and
  hospital discharge data.
• This study showed an increased risk for uterine
  rupture with trial of labor, and even greater
  risks with induction (in turn greater still with
  use of prostaglandins).
• No data was presented concerning the location of
  the uterine rupture in relation to the uterine
  scar.

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What Level of Evidence Does This Study Represent?

• Maybe II-2, or perhaps II-3
• Or perhaps, based on Greenes editorial
• Class 2 Other prospectively collected data or
  Class 3 Expert opinion
• Does this study provide convincing evidence
  sufficient to recommend against recommending
  trial of labor? No but it definitely argues
  against the increased risks associated with
  induction without or with prostaglandins for
  trial of labor.
• There may be a cautionary tale in the
  Lydon-Rochelle paper, but it is not a blanket
  injunction against VBACs.

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Minkoff and Chervenak on Elective primary
Cesarean delivery

• Reviews history of this concept since 1985.
• Describes risks and benefits of elective primary
  Cesareans for both mother and fetus.
• Does not perform either a systematic review or a
  meta-analysis.
• Summarizes the research literature (without any
  documentation to substantiate the statement)
• Unfortunately, the interpretation of many of the
  relevant studies on the subject is limited by
  their designs and by conclusions that sometimes
  conflict.

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Minkoff and Chervenak on Elective primary
Cesarean delivery (continued)

• Concludes with the following statement
• Although the evidence does not support the
  routine recommendation of elective cesarean
  delivery, we believe that it does support a
  physicians decision to accede to an informed
  patients request for such a delivery.
• NEJM 2003 Mar 6348949.

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Commentary on Elective Cesareans
That women are seeking elective cesarean
deliveries is probably more significant in that
it indicates failures of modern medicine and
society at large in the sense that women may fear
the experience of labor, and birth attendants may
fear the legal risks of allowing appropriate
women to have a trial of labor. Modern management
of labor should be reassessed to address the
concerns raised by proponents of elective
cesarean delivery. If elective cesarean delivery
becomes an acceptable alternative, we may never
be able to undo the practice.
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How do these influential publications rate in
terms of EBP?

• Do any of them provide systematic reviews or
  meta-analytic summaries of the evidence?
• Are they based on randomized controlled clinical
  trials? Or well-designed multi-center cohort or
  case-control studies?
• Are they based on expert opinion?

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Evidence-based Malpractice

• Perhaps these studies are the leading edge of a
  new phenomenon in clinical care Evidence-based
  Malpractice.
• Practitioners of EBP sometimes forget the
  criteria for making clinical decisions, but none
  of the proponents of EBP would ever recommend
  that editorials and commentaries by influential
  physicians should form the basis for sea changes
  in clinical management.
• And yet, in the case of C-sections and VBACs,
  this appears to be what has happened in the US in
  the past four years.

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Trends in Cesarean Deliveries and VBACs,
United States 1990-2002
30.0
25.0
20.0
Percent of Live Births
15.0
Total C- Section
10.0
Rate
Primary C-Section
Rate
5.0
VBAC Rate
0.0
1989
1990
1994
1995
1996
1997
1998
1999
2000
2001
2002
1991
1992
1993
Year
37
What does the future hold?

• Will rates of primary C-section rise dramatically
  in the coming years?
• Will any obstetricians be willing to permit women
  with previous Cesarean delivery to undergo trial
  of labor?
• Will anyone care?

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Questions or thoughts?

• rkirby_at_uab.edu
• 205-934-2985