Diffusion MRI findings in monochorionic twin pregnancies after intrauterine fetal death.

BACKGROUND AND PURPOSE Monochorionic twin pregnancies complicated by the IUFD of 1 twin are associated with substantial morbidity to the survivor twin. The aim of this study was to determine whether fetal sonography, T2 MR imaging, and DWI can diagnose acute cerebral lesions in the survivor of an MC twin pregnancy shortly after fetal death of the co-twin. MATERIALS AND METHODS During the study period (2007-2010) 34 cases of single IUFD were evaluated. Group A included 6 cases complicated by spontaneous IUFD. Group B had 10 cases of fetal death shortly after treatment of severe TTTS. These were compared with group C, with 18 pregnancies treated by selective termination due to severe complications in MC pregnancies. RESULTS Altogether 9/34 patients had abnormal prenatal cerebral findings. In group A, in 2/6 of pregnancies with spontaneous death, MR imaging showed findings of severe cerebral infarct, while cerebral damage was not evident by sonography. In another case, the surviving fetus was found to be hydropic on sonography, while MR imaging findings were normal. In group B, in 1/10 cases, cerebral infarct was demonstrated only by DWI. In 2 other cases, sonographic findings were normal, but MR imaging showed germinal matrix bleeding. In group C, in 1/18 cases, only DWI showed bilateral cerebral ischemia. In 2 other cases, MR imaging findings suggested germinal matrix bleeding and focal changes in the basal ganglia. In both cases, fetal sonographic findings were normal. CONCLUSIONS In our study, early manifestations of cerebral ischemia in monochorionic twin pregnancies were better diagnosed with MR imaging, especially with DWI.