Flow Chart

Chorionicity and Amnionicity

Surveillance of Monochorionic Twins

Unequal Placental Sharing

Twin-Twin Transfusion Syndrome (TTTS)


Treatment of TTTS

  • Fetoscopic laser ablation

–Quintero stage II–IV disease

–Gestational age between 16 weeks 0 day and 26 weeks 0 day of gestation

–Maternal complications such as placental abruption (1%) and intra-abdominal leakage of amniotic fluid (3%)

–Goal: Laser coagulation of the entire vascular equator

  • Ultrasound surveillance with MCA Doppler after treatment

–Weekly to assess for recurrent twin-twin transfusion syndrome or the development of twin anemia–polycythemia sequence for 6 weeks

–Then, every 2 weeks as with uncomplicated monochorionic gestation

  • Amnioreduction for non-laser candidates (after 26 weeks)
  • Selective feticide/Radiofrequency ablation (rarely performed):

–Usually performed after 16 weeks

–Discordant for a major structural abnormality

–One of the twins is moribund

–Severe IUGR of one twin


Twin Reverse Arterial Perfusion Sequence

Twin Anemia Polycythemia Sequence

US Evaluation of Twin Pregnancies Importance of Chorionicity and Amnionicity PPT

RSNA US Evaluation of Twin Pregnancies - Importance of Chorioncity and Amniocity