Comparison of associated high-risk factors and perinatal outcome between symmetric and asymmetric fetal intrauterine growth retardation

This study compares associated high-risk factors and perinatal outcome between 273 symmetric and 445 asymmetric infants with intrauterine growth retardation. No differences were seen in 17 obstetric, medical, and environmental-behavioral high-risk factors between symmetric and asymmetric intrauterine growth retardation. In preeclampsia, the incidence of symmetric intrauterine growth retardation is higher than that of asymmetric intrauterine growth retardation. The timing of the interaction between the high-risk factor and the stage of gestation is more important than the specific high-risk factor in determining whether symmetric or asymmetric intrauterine growth retardation is produced. On comparison of perinatal outcome between the two groups, we concluded: (1) that the onset of symmetric intrauterine growth retardation occurs much earlier in the course of pregnancy than does asymmetric intrauterine growth retardation, (2) that more symmetric than asymmetric pregnancies with intrauterine growth retardation result in preterm delivery, (3) that the neonatal morbidity rate for symmetric intrauterine growth retardation is higher than that for asymmetric intrauterine growth retardation, and (4) that term symmetric infants with intrauterine growth retardation tend to have a lower mean birth weight and a higher incidence of small placentas than term infants with asymmetric intrauterine growth retardation.