Table 2.

Quintero staging system.

Stage
Stage I	Polyhydramnios–oligohydramnios
Stage II	No visualization of the fetal bladder in the donor twin
Stage III	Doppler abnormalities Absent/reversed umbilical artery end-diastolic flow Reversed a wave flow in the ductus venosus Pulsatile umbilical vein flow
Stage IV	Fetal hydrops in one or both twins
Stage V	Fetal demise of one or both twins