Antenatal prediction of women at increased risk for infants with low birth weight. A discriminant analysis of maternal characteristics known at 24 weeks

Prenatal factors known to be associated with delivery of an infant with low birth weight (LBW) were studied in 165 women who were delivered of infants of 25,000 gm or less, as well as 154 women who were delivered of term infants with normal birth weights (greater than 2,500 gm). Data included information related to th clinical course of the pregnancy through 24 weeks' gestation. Of 25 characteristics measured prenatally, 10 variables were identified with indicated differences between the LBW and normal birth weight groups sufficient to make them suitable for a discriminant analysis. Following further analysis and attribute reduction, eight variables were selected as the final set of discriminating attributes. These are: maternal age, height, and weight, the patients's perception of her own parental treatment as a child, presence of uterine anomalies, bleeding during pregnancy, suspected multiple gestation, and number of previous pregnancies ending with a gestational age of 13 through 36 weeks. On the basis of coefficients derived for each of these variables, an equation was developed to derive a discriminant score for each patient. With the use of such equations, 73.5% of the known cases were correctly classified into groups with low and high birth weight. A similar high correct classification of cases was made when suspected multiple gestation was excluded as a variable.