Influence of maternal parity, height and neonatal gender on the birth weight of normal newborns

Background: The most important determinant of birth weight is gestational a ge. However other biological variables may influence this parameter. Aim: T o study the influence of a maternal parity, height and neonatal gender on t he birth weight of normal newborns in a public Hospital of Southern Chile. Material and methods: A computer registry of all deliveries attended in Tem uco Hospital between 1993 and 1998 was analyzed. Normal deliveries giving b irth to newborns of more than 2,500 g and from women who did not suffer fro m conditions that could influence birth weight, such as hypertension, under nutrition of smoking,were selected. Results: From 27,736 deliveries, 12,580 were selected for the study. Male newborns with gestational ages from 37 t o 42 weeks, had a higher weight than their female counterparts. Multiparous women and those with a height eve,over 154 cm gave birth to I newborns wit h a higher weight than multiparous women or than those with a height of les s than 154 cm. Conclusions: According to these results, birth weight must b e corrected by gender and maternal features, to define those newborns that have a low birth weight for their gestational age.