ULTRASONIC PREDICTION OF DISCORDANT GROWTH IN TWIN PREGNANCIES

In this prospective study conducted from 1984 through 1987, the abilit y to correctly predict growth discordancy in twin gestations by ultras onic estimated fetal weights is examined. Discordancy was defined as a n intertwin birth weight difference of 25% or greater. This method res ulted in a sensitivity rate of 77% and a specificity rate of 92%. The positive predictive value of an abnormal test (i.e. discordant growth) was 67% and the negative predictive value of a normal test (i.e. conc ordant growth) was 95%. The perinatal mortality rate of 217/1,000 in d iscordant twin fetuses was significantly higher than 29/1,000 in the c oncordant twins in this study population (p < 0.01) and even more of a contrast to the rate of 10/1,000 in our singleton population. Accurat e prediction of discordant twin pregnancies which are at high risk for poor outcome opens the opportunity for potential in utero treatment m odalities.