Quintero staging system - twin to twin transfusion syndrome

Stage	Parameter	Criteria
1	MVP of amniotic fluid	MVP<2cm in donor and MVP>8cm in recipient
2	Fetal bladder	Fetal bladder in donor twin is not visualized over 60min observation
3	Doppler waveforms:	At least one of these 3 abnormalities:
	a-umbilical artery	Absent or reversed diastolic flow.
	b-ductus venosus	Reversed a-wave flow.
	c-umbilical vein	Pulsatile umbilical vein flow.
4	Fetal hydrops	Hydrops in one or both twins
5	Fetal cardiac activity	Absent cardiac activity – fetal demise in one or both twins.

Quintero system classified the disease into 5 stages based on the ultrasound findings. 5 parameters are assessed to stage the disease. The parameters include: 1) maximum vertical pocket (MVP) of amniotic fluid, 2) fetal bladder, 3)Dopplers abnormalities of the umbilical artery or ductus venosus, or umbilical vein, 4)fetal hydrops and 5)fetal cardiac activity.

Stage 1 disease occurs when the is only discordance in the amniotic fluid volume, the 1st criteria, which is detected by comparing the measurement of the maximum vertical pocket of the amniotic fluid in each amniotic sac of the donor twin and the recipient twin, with the absence of the other 4 criteria. When maximum vertical pocket of the amniotic fluid in donor sac less than 2cm and maximum vertical pocket of the amniotic fluid in recipient sac is more than 8cm, the disease is at least at stage 1. 

The presence of 2nd criteria that is non-visualization of donor twin bladder indicates at least stage 2. The disease is at least stage 3 when there is presence of the 3rd criteria that is the presence of any of these dopplers abnormalities: 1) absent or reversed diastolic flow of the umbilical artery, 2) reversed of a-wave flow of the ductus venosus or 3)pulsatile flow of the umbilical vein. Fetal hydrops (4th criteria) indicates at least stage 4 and when there is fetal demise (5th criteria) the disease already at stage 5.

-Maximum vertical pocket measurement-

-umbilical artery, ductus venosus and umbilical vein shown-

hydrops - ascites, pleural effusion and scalp edema shown-