Midtrimester abortion induced by Radix trichosanthis: morphologic observations in placenta and fetus.

Since 1971 Radix trichosanthis has been used to induce midtrimester abortion in China. Radix trichosanthis is a traditional Chinese drug extracted from the root of Trichosanthis kirilowii maxim. Intramuscular, intravenous, or intraamniotic injection of the drug may lead to abortion. The time from induction to delivery and the clinical and morphologic changes occurring in the placenta and fetus vary somewhat, depending on the route of injection. The essential changes in the placenta are degeneration and necrosis of the syncytiotrophoblast and thrombosis of the intervillous spaces. In comparison with intramuscular or intravenous injection, intraamniotic injection has the advantage of a shorter interval from induction to delivery (normally 1 to 3 days), milder pathologic changes, and, generally, absence of systemic side effects. The chief element of the agent is vegetable protein, which may cause allergic reactions. A skin test before treatment is strongly recommended.