Russia, Africa, Thailand. Parasitic fetus is a rare congenital disease, also known as "fetal fetus" in genetics, with an incidence rate of one in 500,000, which means that a part of a complete carcass parasitizes another or several incomplete carcasses. Parasitic fetus is relatively rare in China, because its prone sites are retroperitoneum and abdominal cavity, showing a gradually increasing abdominal mass. Newborns who are "boarding" often show that their stomachs are obviously bigger than other children, but they don't eat much, and occasionally they don't want to eat or sleep. So apart from India, Russia, Africa, Thailand has a history.