Abstract
BACKGROUND: Congenital cytomegalovirus (CMV) infection represents a significant public health concern as the most prevalent viral infection in newborns, potentially leading to severe neurological and developmental complications. The majority of cases are asymptomatic and remain undetected during pregnancy due to the absence of effective screening methods. CASE SUMMARY: A 27-year-old primigravida presented for early pregnancy ultrasound, which revealed an atypical finding: A normal anechoic thalamus appearing hyperechoic on the mid-sagittal view of the fetal head. Subsequent ultrasound examinations during mid and late gestation demonstrated classic intracranial features suggestive of congenital CMV infection. Chromosomal karyotyping and microarray analysis of the fetus yielded no significant abnormalities. Following comprehensive prenatal counseling regarding potential adverse fetal outcomes, the patient elected to continue her pregnancy. She ultimately underwent cesarean delivery at 42 weeks gestation at another facility, resulting in the birth of a female neonate. At five months of age, the infant presented with epilepsy and significant growth and developmental delays. CONCLUSION: Congenital CMV infection occurs during the first trimester may manifest as hyperechoic thalamus which can be revealed by ultrasound in the mid-saggital view of the fetal head. Future research should investigate the correlation between echogenic thalamus and developmental outcomes, as well as explore early screening techniques for suspected congenital CMV infection cases.