Flow velocity waveforms of the fetal circulation preceding fetal death in a case of lupus anticoagulant.

Flow velocity waveforms of the vascular system were evaluated at 25 weeks 2 days and 27 weeks 5 days of gestation in the case of a severely growth-retarded fetus. At the first scan, the cerebral vessels displayed low pulsatility indexes, reflecting the brain-sparing pattern that characterizes fetal stress. This compensatory reduction was lost at the time of the second, "preterminal" scan.