Prognosis and long-term outcome of IUGR.
A. Mortality:
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Mortality
↑ with decreasing gestational age when FGR is also present.
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Mortality
↓ by 48% for each week that the fetus remains in utero before 30 weeks’
gestation.
B. Postnatal Growth Impairment:
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usually,
Term SGA have adequate catch-up growth
during the first 12 months without pharmacologic intervention and in most cases
catch-up growth is complete by two years.
-
However,
it is having been suggested that SGA children aged 2−4 years with no evidence
of catch-up growth and heights less than –2.5 SD should be referred for
endocrine evaluation and eligibility for growth hormone (GH) treatment [for a
minority, growth hormone therapy (started before 8 years of age and continued
for >7 years) can augment growth parameters.
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Preterm SGA infants can take 4 or more years to achieve heights in a
normal range.
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Many
preterm infants show a postnatal growth deficit at the time of hospital
discharge, so-called extrauterine growth restriction (EUGR), which is defined
as a centile at discharge lower than the birth centile.
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EUGR
is largely due to an inadequate postnatal nutrient intake as well as postnatal
morbidities, and it ↑ with decreased gestational age.
-
Premature
infants with EUGR also have metabolic abnormalities similar to those observed
in term SGA children and these occur irrespectively of whether they are SGA or
AGA at birth.
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SGA
term infants suffer from an adverse fetal environment during the last trimester
of pregnancy, whereas very preterm infants suffer from an adverse postnatal
environment during the first three months, a time biologically equivalent to
the third trimester of fetal life.
C. Neurological and developmental delay
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Neurodevelopmental
morbidities are seen 5 to 10 times more often in FGR infants compared with AGA infants
and depend not only on the cause of FGR but also on the adverse events in the
neonatal course (eg, perinatal depression or hypoglycemia).
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Even
without identified perinatal events, IUGR infants have a higher incidence of
long-term neurologic or developmental handicaps.
-
Many
studies reveal evidence of minimal brain dysfunction, including hyperactivity,
short attention span, and learning problems.
-
Preterm
FGR infants also show alterations in early neurobehavioral functions, such as attention-interaction
capacity and cognitive and memory dysfunction, that persist.
-
Increased
risk of cerebral palsy, a wide spectrum of learning disabilities, mental
retardation, developmental delay, and neuropsychiatric disorders are seen in
later years.
-
The
most important predictor of subnormal performance is the absence of catch-up
growth in height and/or head circumference.
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Long-term
exclusive breastfeeding could help to prevent some of the neurological sequelae
of being born SGA. Overfeeding with an enriched formula could accelerate
growth, but it does not seem to lead to an advantage for intellectual
development and could increase metabolic and cardiovascular risks.