Subchorionic placental cyst: a cause of fetal growth retardation--ultrasound and color-flow Doppler diagnosis and follow-up.

Subchorionic placental cysts are ominous findings. When attached near the umbilical cord insertion, the risk of umbilical cord constriction is increased. This may cause fetal growth retardation and intrauterine asphyxia. This article reports a case of subchorionic placental cyst diagnosed in the first trimester by transvaginal ultrasound. Color Doppler ultrasound demonstrated a reduction of the umbilical cord bloodstream as the cyst increased in size. Fetal growth retardation was evident in the third trimester.