S
imões
R
et
al
.
492
R
ev
A
ssoc
M
ed
B
ras
2015; 61(6):489-494
(95CI: 0.71 to 1.41) and OR=0.85 (95CI: 0.61 to
1.19), respectively.
2. Malloy MH, et al. (
B
).
6
•
•
Design: non-concurrent observational longitudi-
nal study.
•
•
Population: retrospective analysis of all births by
C-section between the years 2000 and 2003 (mater-
nal demographics, chosen mode of delivery and
neonatal morbidity and mortality were crossed).
•
•
Outcome: neonatal morbidity and mortality.
•
•
Result: information of a total of 422,001 live births
was available for analysis. After adjustment by lo-
gistic regression conducted for length, weight, gen-
der, Apgar score at 5 minutes, breech presentation,
and presence of any medical complications of the
mother or during labor, the authors found an
odds
ratio
for neonatal mortality at gestational ages 32,
33, 34, 35 and 36 weeks of 1.69 (95CI: 1.31 to 2.20);
1.79 (95CI: 1.40 to 2.29); 1.08 (95CI: 0.83 to 1.40);
2.31 (95CI: 1.78 to 3) and 1.98 (95CI: 1.50 to 2.62),
respectively.
3. Högberg U, et al. (
B
).
7
•
•
Design: non-concurrent observational longitudinal
study including data from seven Swedish centers.
•
•
Population: retrospective analysis of all births oc-
curred from 1990 to 2000 (data on 2,094 children
with gestational ages from 23 to 27 +6/7 weeks were
analyzed).
•
•
Outcome: neonatal morbidity and mortality.
•
•
Result: at a gestational age from 23 to 25 weeks,
38% of births were by C-section, while at a gesta-
tional age of 26 to 27 weeks, 66% of births occurred
by this mode of delivery. After excluding the cases
of preeclampsia/eclampsia, the authors observed
that the birth of fetuses in cephalic presentation
occurred vaginally showed no significant difference
with respect to neonatal mortality compared with
those born by C-section.
4. Arpino C, et al. (
B
).
8
•
•
Design: non-concurrent observational longitudi-
nal study.
•
•
Population: retrospective analysis of all preterm
births.
•
•
Outcome: neonatal morbidity and mortality.
•
•
Result: in newborns with gestational age <32 weeks,
C-section did not determine a protective effect on
abnormalities identified using cranial ultrasonog-
raphy (birth trauma). Likewise, in newborns aged
32 weeks or more, after controlling for confound-
ing factors, no protective effect was identified with
the indication of C-section.
5. Ahmeti F, et al. (
B
).
9
•
•
Design: non-concurrent observational longitudi-
nal study.
•
•
Population: cohort included 12,466 births, and was
studied retrospectively. Analysis of neonatal mor-
tality associated with mode of delivery (vaginal or
C-section) was conducted according to birth weight
(500 to 999 g; 1,000 to 1,499 g; 1,500 to 1,999 g;
and 2,000 to 2,499 g).
•
•
Outcome: neonatal mortality.
•
•
Result: 1,135 premature births resulting in 1,189
premature infants were identified. The global rate
of C-section was 32%. Among preterm infants with
birth weights between 500 and 999 g, 5.7% were
born vaginally, compared with 0.4% born by C-sec-
tion. As for the other groups, a higher percentage
of C-sections (3.2% for weight between 1,000 and
1,499 g; 8.8% from 1,500 to 1,999 g; and 19.8% for
those weighing 2,000 to 2,499 g) was identified. The
authors observed lower mortality associated with
C-section in infants with birth weights of 1,000 to
1,499 g (p <0.01).
6. Sonkusare S, et al. (
B
).
10
•
•
Design: non-concurrent observational longitudi-
nal study.
•
•
Population: in all, 124 preterm newborns (gesta-
tional age between 30 and 35 weeks) were analyzed.
Outcomes related to 70 neonates born vaginally
were compared to the outcomes of 54 infants born
by C-section (indication mainly due to maternal
hypertension and oligohydramnios).
•
•
Outcome: perinatal morbidity and mortality.
•
•
Result: as for mortality, it was higher among those
born by C-section compared to vaginal birth (20
versus
10%, respectively), despite the difference be-
ing non significant. Regarding neonatal morbidi-
ty, no significant differences between the delivery
modes were identified.
7. Ghi T, et al. (
B
).
11
•
•
Design: non-concurrent observational longitudi-
nal study (1990 to 2007).
•
•
Population: births of singletons with gestational
age between 25 and 32 +/-6/7 weeks (n=109) were