RESUMO
Nearly 100% of monochorionic twin pregnancies have vascular anastomoses and a fourth of those has clinical features of twin-to-twin transfusion syndrome. Cerebral palsy, microcephaly, porencephaly, and multicystic periventricular leukomalacia are serious antenatal neurologic complications associated with vascular communications in monochorionic twin gestation. It is most likely that such neurological damage is caused by intrauterine cerebral ischemic necrosis. The intermittent blood flow reversal or sudden hypotension in one twin, or emboli of thromboplastic material originating in the dead fetus could cause in utero cerebral damage in the other twin. In this report, we present a case of antenatal periventricular leukomalacia in monochorionic twin pregnancy complicated with twin-to-twin transfusion syndrome.