How accurate is antenatal sonographic identification of discordant birthweight in twins?

The association between discordant birth weight in twins and poor perinatal outcome is well recognised. Antenatal identification of discordant fetal growth in twins using ultrasound has been previously reported. In this study we have assessed the accuracy of interpair percentage estimated fetal weight difference determination (interpair EFW%) in identifying an interpair percentage birth weight difference (interpair BW%) of greater than or equal to 20% and greater than or equal to 25% in 85 twin pregnancies.