What ultrasound findings are associated with congenital varicella syndrome?

Congenital varicella syndrome (CVS) is a condition that occurs when a fetus is exposed to the varicella-zoster virus (VZV) during the first trimester of pregnancy, particularly between 8 and 20 weeks of gestation. The ultrasound findings associated with CVS typically include inadequate growth of the fetus (IUGR), limb hypoplasia (underdevelopment of the limbs), and microcephaly (reduced head size due to brain underdevelopment).

IUGR in the context of CVS results from the impact of the viral infection on placental function and fetal growth. Limb hypoplasia reflects the teratogenic effects of the virus on developing limbs, which can lead to various limb abnormalities. Microcephaly occurs because the virus can interfere with normal brain development, leading to smaller head sizes at birth.

Understanding these associated findings is crucial in the clinical assessment of a pregnant woman with a history of varicella infection and helps guide further evaluation and management.