Quintero Staging (Twin-Twin Transfusion)

What the result means

Entry

A monochorionic diamniotic pregnancy with the oligohydramnios-polyhydramnios sequence: donor maximum vertical pocket under 2 cm AND recipient over 8 cm.

Stage I

The fluid sequence, donor bladder visible, Dopplers normal in both twins.

Stage II

The fluid sequence, donor bladder NOT visible over 60 minutes of observation, Dopplers still normal.

Stage III

Critically abnormal Dopplers in either twin: absent or reversed umbilical artery end-diastolic flow, a reversed ductus venosus a-wave, or pulsatile umbilical venous flow.

Stage IV

Hydrops.

Stage V

Demise of one or both twins.

Not a size difference

Discordant growth WITHOUT the fluid sequence is selective fetal growth restriction, a different condition with different management. Staging on growth names the wrong disease.

Not a ladder

The stages order findings, not the course. Progression from I to V is not obligate, a pregnancy can present at stage IV, and a higher stage does not guarantee faster deterioration.