Table 1.

MCDA complications and their diagnostic criteria.

Ultrasound Parameters	Diagnostic Criteria	Complications
Amniotic fluid discordance	DVP < 2 cm and >8 (<20 weeks) or >10 (>20 weeks) cm	Twin-to-twin transfusion syndrome (TTTS)
Fetal biometry and Doppler	-EFW < 3rd centile in one twin OR >2 criteria among -EFW and/or AC < 10th percentile -UA PI > 95th percentile -EFW discordance > 25%	Selective fetal growth restriction (sFGR)
MCA-PSV	MCA-PSV > 1.5 MoM in one twin and <1 MoM in the other	Twin anemia polycythemia syndrome (TAPS)

DVP = deepest vertical pocket; EFW = estimated fetal weight; AC = abdominal circumference; UA = umbilical artery; PI = pulsatility index; MCA = middle cerebral artery; PSV = peak systolic velocity; MoM = multiple of medians.