ADJUSTMENT OF BIRTH-WEIGHT STANDARDS FOR MATERNAL AND INFANT CHARACTERISTICS IMPROVES THE PREDICTION OF OUTCOME IN THE SMALL-FOR-GESTATIONAL-AGE INFANT

OBJECTIVE: Birth weight is a function of gestational age. Various mate rnal and infant characteristics also affect birth weight. This study s ought to adjust for these factors to better define abnormal growth. ST UDY DESIGN: Maternal and infant characteristics from normal pregnancie s were correlated with birth weight. A formula was developed and appli ed to a second group in which we compared perinatal outcomes in normal ly grown infants with those who were small for gestational age. We com pared outcomes between small-for-gestational-age infants defined by th e formula with those defined by conventional tables. RESULTS: Infants defined by the formula as small-for-gestational-age were more likely t o have morbidity and mortality than those who were normally grown (p < 0.001). Small-for-gestational-age infants defined by the formula had more deaths and adverse outcomes than those defined by gestational age . CONCLUSION: Adjusting birth weight standards for maternal and infant characteristics may improve the prediction of adverse outcomes.