Placental histology in women with pregnancy-associated TTP and following treatment. (A) Pretreatment delivery at 28 weeks’ gestation: placenta showing an infarct (arrow). (B) Pretreatment delivery at 28 weeks’ gestation: distal villous hypoplasia, indicating ischemia (hematoxylin and eosin ×200). (C) Subsequent delivery following treatment at 36 weeks’ gestation: normal villi (hematoxylin and eosin ×200).