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N
utritional
practices
and
postnatal
growth
restriction
in
preterm
newborns
R
ev
A
ssoc
M
ed
B
ras
2015; 61(6):500-506
503
The infusion of glucose with amino acids on the first day
of life decreases protein catabolism, increases protein in-
corporation rates, can help lower plasma glucose concen-
trations and should be started within the first days of
life.
17,19
Studies comparing a high
versus
low supply of ami-
no acids in the first days of life showed that high protein
supplies resulted in increased protein incorporation with-
out increasing toxicity,
20-26
with initial supplies of 3.0 g/
kg/day being recommended. In our study, only 53% re-
ceived amino acids in the first 48 hours of life, and the
initial and maximum supplies were low, taking 6 to 7 days
to reach the maximum supply. This practice exposed new-
borns to a negative protein balance and may have con-
tributed to the low supply of glucose and energy.
Lipid emulsions are fundamental in PN for preterm
newborns to meet the energy requirements for mainte-
nance and growth and to prevent a deficiency of essential
fatty acids. Lipid administration strategies include a min-
imum supply of 0.5 to 1.0 g/kg/day, starting on the first
day of life, increasing 0.5 to 1.0 g/kg day to a maximum
of 3.0 g/kg/day, attained in 4 to 5 days.
15,16,27,28
In this
study, approximately 50% of patients received lipid emul-
sion after 48 hours of life, the initial and maximum dos-
es were low and it took 6 to 7 days to reach the maximum
dose. This lipid supply was sufficient to meet the essen-
tial fatty acid requirements, but contributed to the low
supply of energy. This conservative approach may have
been the result of concerns with toxicity. However, a me-
(20.6%), in G1, and 49 (46.2%), 35 (33.0%) and 22 (20.8%),
in G2, both without statistically significant differences.
The duration of PN was longer (p=0.006) in G1 compared
to G2. There was a significant difference between the
groups for most of the EN variables (Table 2). Seven chil-
dren (11.1%) in G1 and 3 children in G2 (2.5%) did not
receive human milk (p=0.002).
Most variables related to neonatal growth were dif-
ferent between the groups
.
The percentage of weight loss
was greater (p=0.009) in G1 (13.4%; 0.4 to 44.7%) than in
G2 (10.0%; 0.7 to 23.3% ), the time to regain birth weight
was longer (p=0.005) in G1 (17.7, 9.5 days) compared to
G2 (12.9, 6.0 days) and the average daily gain was lower
(p=0.000) in G1 (20.5, 0.8 g) compared to G2 (25.7, 2.5 g).
The time to reach 1800 g was longer (p=0.000) in the ex-
tremely low birth weight at birth group (46 days; 9 to 81
vs
. 21 days; 9 to 25). The frequency of SGA infants at post-
conceptual age of term was higher in G1, 52 (82.5%)
vs
.
88 (72.7%), but without statistical significance (p=0.139).
To assess the factors associated with maximum
weight loss greater than 10% of birth weight, time to re-
gain birth weight greater than 14 days and frequency of
SGA at post-conceptual age of term, the logistic regres-
sion model included gender, birth weight, SGA at birth,
respiratory distress syndrome, sepsis, necrotizing entero-
colitis, mechanical ventilation > 7 days, use of PN > 8
days, maximum glucose supply < 16.0 g/kg/day, maxi-
mum amino acid supply < 2.0 g/kg/day, maximum lip-
id < 2.0 g/kg/day and energy supply < 60 kcal/kg/day
and time to achieve exclusive EN and energy supply of
120 kcal/kg/day by EN for more than 14 days. The re-
sults are presented in Table 3.
D
iscussion
With the increase in the survival of newborns with very
low weight, reduction of morbidities and improved prog-
nosis in the long term have become priorities. As such,
neonatal nutrition is essential for adequate growth and
development of preterm newborns.
According to recent recommendations, PN can be ini-
tiated within the first hours of life, and is safe and effec-
tive even in very premature infants.
13-15
In this study, PN
was administered to 92% of newborns, but only 50% start-
ed it within the first 48 hours of life. Glucose administra-
tion was performed early, with an appropriate initial sup-
ply,
16,17
and although the duration of PN was sufficient,
the maximum supply achieved was lower than recom-
mended. The incidence of hyperglycemia is high in ex-
tremely premature infants and may limit the administra-
tion of glucose in these newborns.
18
TABLE 3
Final logistic regression model to assess the
relationship between clinical and nutritional variables and
growth variables.
OR 95CI
p
Weight loss >10% of
birth weight
Respiratory distress syndrome
3.024 [1.385; 6.605] 0.005
>14 days to 120 kcal/kg/day
3.442 [1.517; 7.719] 0.030
> 14 days to regain birth weight
SGA
0.302 [0.127; 0.717] 0.007
Sepsis
2.636 [1.254; 5.540] 0.010
Maximum energy via PN <60
kcal/kg/day
3.029 [1.425; 6.442] 0.004
>14 days to 120 kcal/kg/day
4.551 [1.753; 11.814] 0.001
Small for post-conceptual
age of term
SGA at birth
9.995 [2.134; 46.826] 0.004
Sepsis
4.253 [1.496; 12.087] 0.006
>14 days for exclusive EN
6.994 [2.174; 22.501] 0.001
PN: parenteral nutrition; EN: enteral nutrition.