First-trimester ultrasound image of umbilical cord

(A) Three-dimensional rendered image of a first-trimester fetus and its umbilical cord. Both the placental and abdominal insertion sites are shown. Note that the umbilical cord length at this gestational age is approximately the same as the crown rump length.
(B) Transvaginal two-dimensional ultrasound shows a transverse view of the fetal abdomen (a), the entire length of the umbilical cord (uc) including its placental and fetal insertion sites, and the physiologic midgut herniation (arrow) at the base of the fetal insertion site.