Objective To study the outcome of fetoscopic laser photocoagulation (laser) in the management of monochorionic diamniotic twin (MCDA) pregnancies complicated with selective intra-uterine growth restriction (sIUGR).Methods Retrospective analysis of 5 MCDA twin pregnancies with sIUGR treated by laser.Results All 5 cases were sIUGR type Ⅱ.In all 5 cases,the growth restriction was associated with oligohydamnios,and the umbilical cord had marginal insertion to the placenta.Abnormal Doppler flow pattern of the ductus venosus was present in 3 cases.Indication for laser therapy was beause of high risk of deterioration and fetal demise of the growth restricted fetus.In all cases,fetal reduction as an alternative was discussed and was refused.The median gestation at laser was 19 weeks.The procedure was successful in all cases,with complete seperation of the vascular anastomoses.There was no case of immediate postoperative complications.Fetal karyotype was normal in all cases.Fetal death of the small twin occurs in all cases within two weeks after surgery.Follow up studies of the surviving twin in all cases showed normal fetal growth,amniotic fluid volume,and middle cerebral artery peak systolic velocity.All cases resulted in preterm labor,with a median gestational age of 32 weeks (30+3 weeks to 34 weeks),and a median birth weight of 1 540 g (1 100-2 080 g) ; the postoperative fetal survival rate was 5/10,with at least one child survival rate of 5/5.There was no neonatal complication in the survival twins.Postnatal pathological examination of the placenta confirmed MCDA twin in all cases.Conclusions Laser treatment of MCDA twin complicated with sIUGR is effective.It protects the normal fetus even when the growth restricted twin died.However,the intention to give a small chance of survival to the growth restricted fetus by avoiding fetal redution procedure was not successful.All of the sIUGR fetuses died due to placental insufficicent.This fact is important during the pre-treatment counselling to avoid unrealistic expectation.