Fetal cardiac ultrasound can be performed during normal labor and delivery examination, or when fetal single umbilical artery, NT thickening, permanent right umbilical vein, jugular hydatid cystic aneurysm, abnormal umbilical cord blood flow, cardiac insufficiency, valvular insufficiency and other developmental anomalies are detected. Generally, around 23-26 weeks of pregnancy, fetal four-dimensional ultrasound examination is performed to clarify the development of the heart, whether there is arterial ductus arteriosus, atrioventricular valve defect, mitral valve, tricuspid valve regurgitation, and so on. Pregnant women who have cardiovascular symptoms, or have excessive amniotic fluid, twin fetuses, hypertensive disorders of pregnancy and other complications and comorbidities during pregnancy can also have a maternal cardiac ultrasound examination to assess their conditions. Usually pay attention to rest, avoid strenuous exercise and exertion.