EFW of small fetus less than 10th centile/EFW discordancy >25% pathophysiology-unequal placental sharing role of vascular anastamosis in natural history-larger interfetal blood flow—type 3 better outcome than type 2 classification-based on umbilical artery doppler into three types complications—IUD of snall fetus with acute TTTS-neurological sequelae in normal twin suerviellance and management of types type 1-expectant management, close followup(weekly/biweekly doppler surviellance) and delivery by 34–35 weeks type 2-long latency to deterioration than singleton. Doppler (Ductus venosus) follow up alternate days (if abnormal DV)0r weekly (normal DV) delivery by 30–32 weeks type 3-intermittent doppler changes due to large AA anastamosis. Weekly followup if DV normal or closer follow up if abnormal. Deliver at 32 weeks role of fetal intervention-GA <24 weeks with AREDF/DV PI >95/discordancy >35%.