Measurements of middle cerebral artery pulsatility index (MCA PI) showed evidence for brain-sparing (low MCA PI) in (A) male fetuses (P = 0.03) (Bars represent mean values & SEM, n = 110 and 103, for males and females, respectively), and in (B) those with smaller placentas (P = 0.02) (Bars represent mean values & SEM, n = 49, 49, 49, and 48, respectively). (C) Greater ductus venosus liver shunting was also related to brain-sparing; MCA PI was lower in fetuses in the highest quarter of the distribution of ductus venosus liver shunting when compared with those in the lowest three-quarters of the distribution (P = 0.04) (Bars represent mean values & SEM, n = 53 and 160, respectively).