The severity of fetal diaphragmatic hernia depends on several factors: 1. gestational age at the time of detection; the younger the gestational age at the time of detection, the more severe the disease. Usually detected after 28 weeks of gestation, the outcome is likely to be better; 2. The lung-to-head ratio (LHR) of the fetus. The larger the ratio, the better the outcome (>1.6, high survival rate); 3. Whether the liver is located above the diaphragm, if so, the prognosis is poor. Therefore, a series of detailed examinations are needed to evaluate and calculate, after combining some other factors to make a judgment. Most of the children with diaphragmatic hernia have a mostly good prognosis with successful treatment.