Mild fetal cerebral ventriculomegaly: Diagnosis, clinical associations, and outcomes

The normal fetal lateral ventricular diameter remains stable at 10 mm over gestation. Mild ventriculomegaly, defined as a lateral ventricular diameter of greater than or equal to10 mm but less than or equal to15 mm or a choroid-lateral ventricular separation greater than or equal to3 mm but less than or equal to8 mm occurs bilaterally in 0.15-0.7% of fetuses and unilaterally in 0.07% of pregnancies. This finding is associated with an increased risk of fetal chromosomal abnormalities, congenital anomalies and infections, syndromes, perinatal death, and childhood developmental delays. Prenatal evaluation includes targeted sonographic examination for central nervous system and extra-central nervous system abnormalities, and diagnostic amniocentesis for chromosomal analysis and infectious disease studies. Individualized patient counseling is based on these test results. Optimal postnatal care involves appropriate pediatric neurologic and developmental specialists. Target Audience: Obstetricians & Gynecologists, Family Physicians Learning Objectives: After completion of this article, the reader will be able to define the normal appearance and size of the fetal cerebral ventricles, to list the conditions associated with mild ventriculomegaly, and to explain the natural course of mild bilateral isolated ventriculomegaly.