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E
lective
cesarean
section
for
term
breech
delivery
R
ev
A
ssoc
M
ed
B
ras
2015; 61(5):391-402
393
Studies selected in the first assessment
After entering the search strategy in the primary databas-
es (PubMed-Medline and Cochrane), the assessment of
titles and abstracts led to the selection of 26 studies.
Evidence selected in critical evaluation and exhibition of results
The studies considered for full text reading were critical-
ly assessed according to inclusion and exclusion criteria,
study design, P.I.C.O., language and availability of the
full text.
Results pertaining clinical status will be displayed in-
dividually, showing the following items: clinical question,
number of studies selected (according to inclusion crite-
ria), description of the studies (Table 2), results and sum-
mary of the available evidence. References related to the
studies included are shown in Table 4.
TABLE 2
Worksheet used for description of studies
included and exposure of the results.
Evidence included
Study design
Population selected
Time of follow-up
Outcomes considered
Expression of results: percentage, risk, odds, hazard ratio
TABLE 3
Critical assessment script for randomized
controlled trials (checklist).
Study data
Reference, study design,
Jadad, strength of evidence
Sample size calculation
Estimated differences, power,
significance level, total number of
patients
Patient selection
Inclusion and exclusion
criteria
Patients
Recruited, randomized, prognostic
differences
Randomization
Description and blinded
allocation
Patient follow-up
Time, losses, migration
Treatment protocol
Intervention, control and
blinding
Analysis
Intention to treat, analyzes of
intervention and control
Outcomes considered
Primary, secondary,
measuring instrument
of the outcome of interest
Result
Benefit or harm in absolute data,
benefit or harm on average
After applying the inclusion and exclusion criteria, the
evidence selected in the search and defined as random-
ized controlled trials (RCT) were subjected to an appro-
priate checklist for critical assessment (Table 3). Critical
assessment of RCTs allows to classify them according to
the Jadad score, so that Jadad < 3 trials are considered in-
consistent (
B
), and those with scores ≥ 3, consistent (
A
).
For critical analysis of non-randomized studies, among
them prospective observational studies, we used the New-
castle-Ottawa scale.
7
For results with available evidence, wherever possible
the following specific items are defined: population, in-
tervention, outcomes, the presence or absence of benefit
and/or damage and controversies.
Cost issues will not be included in the results.
The results will be presented preferably in absolute
data, absolute risk, number needed to treat (NNT), or
number needed to harm (NNH), and occasionally in mean
and standard deviation.
R
esults
Clinical question
Is the performance of elective C-section in singleton term
pregnancies in breech presentation related to lower ma-
ternal, peri- and neonatal morbidity and mortality com-
pared with vaginal delivery?
Evidence selected
TABLE 4
Selection process.
Type of publication
Included
Randomized clinical trials
4
(8,9,12,14)
Concurrent cohort studies
2
(18,19)
Non-concurrent cohort studies
20
(10,11,13,15-17,20-32)
The main reasons for the exclusion of works were the
unavailability of the full text, longitudinal observation-
al (retrospective or prospective) or experimental (con-
trolled clinical trials, randomized or not) studies with
different study design, studies that included preterm fe-
tuses (gestational age <37 weeks), or those using only
the estimated weight of the fetus as a criterion for in-
clusion.
Results of the evidence selected
Of the 1,943 articles initially retrieved, 26 were selected
to support the summary of evidence concerning mater-
nal, perinatal and neonatal morbidity and mortality, ac-
cording to mode of delivery chosen in cases of singleton
term pregnancies in breech presentation. Studies includ-
ed are shown in Table 4.