Our objective was a retrospective evaluation of cranial US in survivors of twin pregnancy with feto-fetal transfusion syndrome (FFTS), with knowledge of prenatal treatment and neonatal/postnatal clinical data. In 18 pregnancies with FFTS (January 1996 to May 2000), pregnancy management and outcome, and neonatal clinical/neurological data and follow-up (age of 3-7 months) were documented when available. Postnatal cranial US abnormalities were differentiated in prenatal and peri/postnatal lesions, respectively, in "donor" and "recipient." The statistical analysis used was Mann Whitney U test and Fisher's exact test. Overall pregnancy survival rate was 19 of 36 (53%); mors in utero occurred in five twin members. Gestational age at birth was significantly lower in FFTS after laser coagulation (13 of 18; p<0.05). Initial (<or=4 days of age) postnatal cranial US was abnormal in 13 of 27 cases: antenatal brain lesion in 9 of 13 patients (7 of 13 donors, 2 of 14 recipients); after treatment: antenatal hemorrhage (n=6), hydrocephaly (n=1), subependymal germinolysis (n=1), lenticulostriatal vasculopathy (n=1), evidence for brain atrophy (n=2), cystic periventricular leukomalacia in<3 days (n=1); peri/postnatal brain lesions in 4 of 13 patients (hemorrhage (n=3), and periventricular leukomalacia (n=1). Finally, an abnormal brain US was found in 18 patients. Twin pregnancies complicated with FFTS are high-risk pregnancies with antenatal and postnatal mortality and morbidity. In utero cranial hemorrhage dominated the antenatal brain insults; however, pregnancy survivors remain at risk for severe peripartal and/or postnatal brain insults.