Objective: The purpose of this study was to evaluate the importance of echogenic material in the fetal frontal horns.
Methods: This was a Health Insurance Portability and Accountability Act-compliant, Institutional Review Board-approved retrospective study. In part 1 of the study, prenatal sonography, prenatal magnetic resonance imaging (MRI), and birth outcomes of 17 fetuses (mean gestational age, 19 weeks; range, 15-34 weeks) with prospective echogenic material in the frontal horns were assessed. In part 2, 400 consecutive sonographic fetal surveys (mean gestational age, 19 weeks; range, 15-38 weeks) were reviewed to determine the incidence. In part 3, 2 independent reviewers assessed the appearance of the frontal horns in 40 fetuses (20 with suspected intraventricular hemorrhage from parts 1 and 2 and 20 who were interpreted to have normal findings in part 2).
Results: Part 1 of the study showed that suspected hemorrhage was unilateral in 13 fetuses and bilateral in 4. Additional findings by sonography were grade 4 intraventricular hemorrhage (n = 2), ventriculomegaly (n = 2), and porencephaly (n = 1). An additional finding by MRI was porencephaly in 1 fetus. In part 2, echogenic material in the frontal horns was identified in 3 of 400 fetuses (0.8%). In part 3, hemorrhage was probably or definitely present in 11 of the 20 fetuses with abnormalities; material looked like a cyst in 6; and normal choroid was in an abnormal position in 2 and a normal position 1. Of 19 fetuses with abnormalities, 14 had a posteriorly symmetric choroid; 9 had material of different echogenicity compared with the choroid; and 17 had an expanded frontal horn. Birth outcomes were abnormal in 7, including platelet abnormalities (n = 2), hemorrhage on imaging or pathologic examination (n = 2), extraventricular hemorrhage (n = 3), and ventriculomegaly (n = 3).
Conclusions: The incidence of echogenic material in the frontal horns is less than 1%. This does not represent the normal location of the choroid plexus and may represent hemorrhage, which may resolve without sequelae or result in ventriculomegaly and porencephaly.