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Overview :
Neonatal
outcome in extremely low birthweight infants can be predicted using data
available before delivery using equations developed by Bahado-Singh et al. The
study was done at the Yale University in New Haven, Connecticut.
Infant
selection: birthweight <= 1,000 grams
Parameters:
(1)
gestational age in weeks
(2)
abdominal circumference in millimeters
probability
of overall survival =
= EXP(-X) /
(1 + EXP(-X))
X =
= 20.8384 -
(0.5553 * (gestational age in weeks)) - (0.03999 * (abdominal circumference in
mm))
probability
of survival without severe morbidities =
= EXP(-Y) /
(1 + EXP(-Y))
Y =
= 29.8361 -
(0.7518 * (gestational age in weeks)) - (0.0415 * (abdominal circumference in
mm))
where:
•
survival indicates being alive at hospital discharge
•
severe neonatal morbidities include high grade retinopathy of prematurity, high
grade intraventricular hemorrhage, periventricular leukomalacia, chronic lung
disease and deafness
•
outcomes could be predicted independent of birthweight
NOTE: The
equations given above are given on page 465 as:
probability
of overall survival =
= 1 / (1 +
(EXP((-1) * (20.8384 + (0.5553 * (gestational age)) + (0.03999 * (abdominal
circumference in mm))))))
probability
of survival without severe morbidities =
= 1 / (1 +
(EXP((-1) * (29.8361 + (0.7518 * (gestational age)) + (0.0415 * (abdominal
circumference in mm))))))
When these
equations are used, the results do not resemble the data shown in Figures 3 and
4 on page 466.
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