EVALUATION OF PERINATAL OUTCOME USING INDIVIDUALIZED GROWTH ASSESSMENT - COMPARISON WITH CONVENTIONAL METHODS

Objective. To evaluate individualized growth assessment using the Ross avik growth model for detection of growth-retarded neonates with poor perinatal outcomes. Methods. Rossavik growth models derived from secon d-trimester ultrasound measurements were used to predict birth charact eristics of 154 singleton neonates. Individual fetal growth curve stan dards for head and abdominal circumference and weight were determined from the data of two scans obtained before 25 weeks' menstrual age and separated by an interval of at least 5 weeks. Comparisons between act ual and predicted birth characteristics were expressed by the Growth P otential Realization Index and the Neonatal Growth Assessment Score (N GAS). The proportions of perinatal outcomes (mechanical delivery, low Apgar score, abnormal fetal heart rate [FHR] patterns, neonatal acidos is, meconium staining of amniotic fluid, neonatal intensive care unit admission, and maternal complications), using NGAS, were compared with those by the traditional birth weight-for-gestational age method and the ponderal index, respectively. Results. Of the 154 fetuses studied, 120 had normal growth outcomes at birth; 18 showed evidence of intrau terine growth retardation; and 16 had macrosomia, based on NGAS. Accor ding to birth weight-for-gestational age classification, 32 fetuses we re small for gestational age; 118 were appropriate for gestational age ; and only 4 were large for gestational age. According to the ponderal index, 55 fetuses had growth retardation 99 showed appropriate growth and there was no macrosomia. There was a significant increase in mech anical deliveries in cases of growth-retarded neonates, determined usi ng the NGAS classification, when compared with events related to norma lly grown or macrosomic neonates. However, there were no significant d ifferences in mechanical deliveries among the groups by birth weight c lassification or ponderal index. Both birth weight classification and NGAS classification showed a significant increase in the low Apgar sco re, abnormal FHR patterns, and neonatal acidosis in infants classified as growth retarded when compared with appropriately grown or macrosom ic infants. However, there were no significant differences in the low Apgar score, abnormal FHR patterns, and neonatal acidosis between grow th-retarded and appropriately grown infants when they had been so clas sified by ponderal index. Three growth category classification methods failed to reveal significant differences in meconium staining of amni otic fluid, neonatal intensive the groups. Conclusion. We do cast doub t on the usefulness of the ponderal index for detection of growth-reta rded neonates with poor perinatal outcomes, and individualized growth assessment seems to perform at least as well as the traditional birth weight-for-gestational age method.