Patterns of Placental Injury in Congenital Anomalies in Second Half of Pregnancy.

Fetal anomalies in second half of pregnancy feature abnormal clinical phenotypes much more frequently than abnormal placental phenotypes. Chromosomal abnormalities with or without heart malformations tend to feature villous edema, and erythroblastosis of fetal blood, likely due to fetal heart failure. Mass-forming fetal anomalies feature placental histological lesions of shallow placental implantation, diffuse chronic hypoxic patterns of placental injury, and lesions of fetal vascular malperfusion, likely stasis-induced.