Should isolated fetal ventriculomegaly measured below 12mm be viewed as a variant of the norm? Results of a 5-year experience in a prenatal referral center

International audienceBackground: Fetal ventriculomegaly (VM) is defined as lateral ventricles measured above 10mm. Some authors believe VM <12mm are variants of the norm and need not be addressed for referral ultrasound.Methods: A retrospective continuous cohort study of 127 confirmed fetal VM was divided into three groups after initial referral sonographic assessment: isolated VM <12mm (group A), isolated VM 12mm (group B), and VM associated with other malformations (group C). We reviewed obstetric outcome and neonate evolution after 1 month with the aim of defining a pertinent prenatal workup.Results: We reported fetal infections in all groups (p=.24) and chromosomal abnormalities only in group C (p=.41). Fetal magnetic resonance imaging (MRI) found initially undiagnosed brain abnormalities in groups B and C (12.5 and 14.1%, p<.05). Ratios of healthy children after 1 month stemming, respectively, from groups A, B, and C were 66.7, 62.5, and 20.2% (p<.05).Conclusions: Our results are in favor of a systematic referral ultrasound for every fetal VM, regardless of size, as soon as definition criterion is met. Additional paraclinical assessment (maternal serologic status for toxoplasmosis and cytomegalovirus, amniocentesis, fetal cerebral MRI) should be discussed depending on the situation