Cavoretto P, Farina A, Gaeta G, et al. - Researchers examined how uterine artery pulsatility index (UtA-PI) during pregnancies conceived by in vitro fertilization (IVF)/ intracytoplasmic sperm injection (ICSI) techniques using either fresh or cryopreserved blastocysts, is related to pregnancy outcomes. In this prospective longitudinal study of singleton evolutive IVF/ICSI pregnancies, they collected and analyzed 625 observations in 367 IVF/ICSI cycles at San Raffaele Hospital at 7-37 gestational weeks (median 2.5; range 2-4; fresh = 164; frozen blastocyst transfer (FBT) = 203 ). Outcome analysis revealed lower UtA-PI and proportion of small-for-gestational-age in pregnancies after frozen as compared with fresh blastocyst transfer. An average 14% lower UtA-PI was reported in the FBT group when compared with the fresh group.