ABSTRACT
The ultrasound assessment of patients with twin-twin transfusion syndrome (TTTS) can be particularly challenging. The presence of oligohydramnios in the sac of the donor twin frequently impairs adequate visualization of the fetal anatomy, fetal gender, and occasionally, adequate Doppler interrogation of the different vessels of this fetus. Polyhydramnios is typically associated with a frequently moving recipient twin, which makes the Doppler assessment of this fetus particularly difficult. Polyhydramnios may also result in significant maternal discomfort with back pain or light-headedness in the recumbent position, hindering further the completion of the ultrasound examination. Lastly, the examination is typically done under an atmosphere of psychological tension from maternal anxiety, given the grave prognosis in most cases. Despite these limitations, a thorough and complete ultrasound examination is necessary to correctly diagnose and assess the status of patients with TTTS.
