[Value of prealbumin in the 1st and after the 12th day of life]. / Valeur de la préalbumine au premier et après le douzième jour de la vie.

From a series of 129 neonates, well defined with regard to weight and gestational age, the authors established that serum concentration of prealbumin (PA) in an aseptic neonate depends on its gestational age on the first day of extrauterine life (p less than 0.001). Serum concentrations of PA are significantly different in appropriate for gestational age (AGA) and small for gestational age (SGA) neonates; this may be the consequence of insufficient materno-foetal transfers in the majority of SGA children. The study of the ratio maternal PA/neonatal PA at the time of delivery helps to establish the cause of SGA. On and after the 12th day of life, serum concentrations of PA are closely correlated with the usual data of anthropometry (weight, height, skull circumference) (p less than 0.001), when correlation is less close with gestational age at the time of sample taking: it may be used as a marker of the appropriateness of gestational age rather than of maturity. However, the ratio PA/weight varies from one child to another and from one week to another for a same child, giving PA a value different from ordinary anthropometry for the evaluation of the appropriateness of gestational size in neonates.