between IUGR and SGA (P = 0.003), IUGR and AGA (P < 0.0001), SGA and AGA P < 0.003). IUGR showed a significant difference in perinatal morbidity between SGA and AGA (P < 0.0001). Conclusions: The present study highlights that aIMT is higher in IUGR compared to SGA vs. AGA and in SGA vs. AGA fetuses, highlighting that Doppler velocimetry and birth weight are predictors of aorta stiffness. Moreover, to our knowledge this is the first study considering aIMT in twin pregnancies, which may be considered a model of study to consider early cardiovascular markers in the same environment.