Selective fetal growth restriction

Selective intrauterine growth restriction (sIUGR) refers to a condition in which the estimated fetal weight (EFW) of one twin is below the 10th percentile for gestational age, and the weight difference between the two fetuses is ≥25%. (This is currently the main diagnostic criterion, but it remains controversial.) This condition is one of the severe complications unique to monochorionic twin pregnancies, with an incidence of approximately 10-15%. The occurrence, natural progression, and outcome of this disease are mainly related to the unbalanced placental area ratio supplying the two fetuses and the presence of different types of placental anastomotic vessels. Clinically, the main manifestation is a significant weight difference between the two fetuses.