Twins:  TRAP (Twin Reversed Arterial Perfusion) Sequence or Acardiac Twinning

 

7.pt.2.acarc

Above. Twin reversed arterial perfusion syndrome; transverse view of both femurs and thighs of the recipient fetus. The fetal thigh circumference of the recipient twin is significantly greater than that of the donor twin. Note polyhydramnios in the donor sac.