OC08.02: The value of delta middle cerebral artery peak systolic velocity for the prediction of twin anemia polycythemia sequence

Abstract

Objectives: Radiofrequency ablation (RFA) is one of the best methods of fetal reduction to improve monochorionic pregnancy outcome; however, twins treated by RFA are still at increased risk of neurodevelopmental impairment. The aim of this study was to investigate the accuracy of fetal ultrasound, conventional magnetic resonance imaging (MRI), and diffusion-weighted imaging (DWI), in diagnosis of intracranial lesions especially hypoxic ischemic brain injury in the survivors. Methods: 43 monochorionic twins with mean gestational age of 20.2 weeks underwent RFA and were assessed between 2018-2020 by ultrasound and MRI (conventional and DWI sequences). Fetal brain imaging was performed in the surviving fetuses, at early (within 10 days after RFA) and late phase (after 3-6 weeks), to determine both acute and chronic ischemic lesions. Presence of anemia after RFA was also evaluated by Doppler ultrasound. Results: Overall, 13 of total 43 (30.2%) fetuses demonstrated MRI abnormalities with normal brain ultrasound results and no anemia including ten germinal matrix hemorrhage (GMH), two extensive cerebral ischemia in DWI and one mild ventriculomegaly. Also, totally 13 (30.2%) fetuses died in utero including 6 fetuses because of PROM, and two cases with extensive cerebral infarct and 5 cases with unknown etiology. Seven fetuses with GMH were eventually born alive with normal outcome. Besides, anemia was noted in 3 (6.9%) fetuses without abnormal findings on MRI. The postnatal investigations of the survivors showed no abnormalities. Conclusions: Fetal brain DWI can detect early intracranial ischemic changes in monochorionic pregnancies after RFA of one fetus, better than ultrasound. GMH seems to be a frequent finding and can be considered with little clinical significance. Normal brain ultrasound and no evidence of anemia in Doppler exam do not necessarily rule out fetal brain ischemia, and performing DWI in early phase is helpful in multiple pregnancies undergoing RFA for better management of pregnancy.