Birthweight by gestational age in preterm babies according to a Gaussian mixture model.
OBJECTIVE
To provide a statistically sound criterion for identifying implausibly large birthweights for gestational age.


METHODS
Review of ISTAT 1990-1994 national newborn records.


METHODS
Italy


METHODS
Forty-two thousand and twenty-nine single first and second liveborn preterm babies.


METHODS
Two-component Gaussian mixture models are used to describe the birthweight distributions stratified by gestational age. Implausibly large babies are identified through model-based probabilistic clustering.


METHODS
Gestational age misclassification and weight-for-gestational age centile curves


RESULTS
Gestational age appears under-estimated by about six weeks in 12.3% of the cases. Large babies are equally present in males and females, but are more frequent in second-borns than in first-borns, even when parity-specific models are fitted.


CONCLUSIONS
The approach allows for a quantification of the gestational age under-estimate error and for data correction through model-based clustering. Correct birthweight distributions and growth curves are also provided.
Tentoni
Stefania
S
Institute of Applied Mathematics and Computer Technologies, CNR, Pavia, Italy.
Astolfi
Paola
P
De Pasquale
Antonio
A
Zonta
Laura A
LA
D001724:Birth Weight; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008954:Models, Biological; D015233:Models, Statistical; D016011:Normal Distribution; D011336:Probability