[Birth weight difference in 3 biological variables in normal newborns].
BACKGROUND
The most important determinant of birth weight is gestational age. However, other biological variables may influence this parameter.


OBJECTIVE
To study the influence of maternal parity, height and neonatal gender on the birth weight of normal newborns in a public Hospital of Southern Chile.


METHODS
A computer registry of all deliveries attended in Temuco Hospital between 1993 and 1998 was analyzed. Normal deliveries giving birth to newborns of more than 2,500 g and from women who did not suffer from conditions that could influence birth weight, such as hypertension, undernutrition or smoking, were selected.


RESULTS
From 27,736 deliveries, 12,580 were selected for the study. Male newborns with gestational ages from 37 to 42 weeks, had a higher weight than their female counterparts. Multiparous women and those with a height over 154 cm gave birth to newborns with a higher weight than nulliparous women or than those with a height of less than 154 cm.


CONCLUSIONS
According to these results, birth weight must be corrected by gender and maternal features, to define those newborns that have a low birth weight for their gestational age.
Lagos
R
R
Hospital Regional de Temuco, Centro de Investigación y Capacitación en Epidemiología Clínica (CICEC), Facultad de Medicina, Universidad de la Frontera, Chile. temco@saval.cl rude@entelchile.net
Espinoza
R
R
Orellana
J
J
Echeverría
P
P
D001724:Birth Weight; D001827:Body Height; D002677:Chile; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010298:Parity; D012016:Reference Values; D012737:Sex Factors