Abdominal ultrasound can be used to visualize the<unk>  site of the umbilical<unk> . Overall, visualization is most successful in the second trimester, however routine ultrasound examination in the second trimester may not detect<unk>  if the condition develops after the remodelling of the placenta as gestation advances. Visualization becomes increasingly difficult in the third trimester as the fetus may obscure the<unk>  site. The umbilical<unk>  and its<unk>  site may be obscured by the fetus, such as in posterior placenta or in low-lying placenta, or may be difficult to visualise due to conditions such as maternal obesity. In these cases, the use of Color Doppler ultrasound or transvaginal ultrasound can enhance the visualization of the umbilical<unk> , and are able to diagnose<unk>  at 18–20 weeks.
Velamentous cord insertion
Neural clique
Vaginal septum
Uterine septum
Fetal movement
Placental expulsion
Peritomy
Circumvallate placenta