Histological appearances of the human placenta observed by electron microscopy after hypertonic saline abortion

Placentae obtained after Hypertonic Saline Induced Abortion (HSIA) were compared with placentae delivered by hysterotomy between 16 and 20 weeks of pregnancy. When investigated by routine light microscopy the greater part of the placental tissue seemed to be normal, changes were confined to a thin subchorionic layer. Transmission and scanning electron microscopy revealed serious damage especially to the syncytium, not only in the subchorial zone but also in the transitional and in the decidual zone. In vitro experiments demonstrated that a very short exposure to hypertonic solution can produce impressive histological changes in placental tissue.