Diagnosis of TTTS is primarily made through prenatal ultrasound. Key diagnostic criteria include:
Monochorionic diamniotic pregnancy confirmed by ultrasound. Significant difference in amniotic fluid levels: Polyhydramnios in one sac (maximum vertical pocket > 8 cm) and oligohydramnios in the other sac (maximum vertical pocket < 2 cm). Discrepancies in fetal size and other ultrasound findings suggestive of TTTS.
