Isolated hyperechogenic foci in the fetal thalamus in early pregnancy

Objective: To describe the sonographic features and outcome of fetuses with isolated hyperechogenic foci in the thalamic region. Methods: A detailed sonographic survey was performed in 46 244 consecutive pregnancies. Both low- and high-risk pregnancies were included. Transvaginal examinations were performed at 14-16 weeks' gestation, while transabdominal examinations were performed after 18 weeks' gestation. Results: Isolated hyperechogenic foci in the thalamic region were observed in seven fetuses. All cases were diagnosed at 14-16 weeks' gestation. Six fetuses had one hyperechogenic focus, and one fetus had two foci. The size of these foci ranged from 2-4 mm. A serologic work-up was negative in all these fetuses and their karyotype was normal. The hyperechogenic foci disappeared in mid-pregnancy in all cases, and fetuses were normal at delivery and on follow up to the age of 9 years. Conclusions: Isolated hyperechogenic foci in the thalamic region in early pregnancy are probably benign in nature.