Unusual maternal vasculature in the placental periphery leading to the diagnosis of abdominal pregnancy at 25 weeks' gestation.

Abdominal pregnancy is a rare condition in which the fetus and placenta are located within the peritoneal cavity. Sonographic findings include visualization of the fetus separate from the uterus, failure to visualize the uterine wall between the fetus and urinary bladder, close approximation of fetal parts to the maternal abdominal wall, eccentric position or abnormal fetal attitude, and visualization of extrauterine placental tissue. We present an unusual case in which mid-trimester transabdominal color Doppler sonographic findings depicted unusual maternal vasculature in the placental periphery leading to the diagnosis of abdominal pregnancy. Postpartum maternal angiography confirmed these vessels as abnormal maternal arterial perfusion of the extrauterine placenta emanating from the uterine arteries and inferior epigastric arteries. Systematic review of the literature confirms that this is the first report of such sonographic manifestations of an abdominal pregnancy.