Prenatal Ultrasound Findings of Pregnancy Associated with Zika Virus Infection

The outbreak of Zika virus followed by an increase in cases of fetal microcephaly in Brazil in 2015 has raised the concern of the association of Zika virus infection with fetal microcephaly and other central nervous system (CNS) malformations. Most patients with Zika virus infection are asymptomatic. However, according to a previous report, the most common symptom in pregnant women with Zika virus infection and fetal microcephaly is rash. Reported prenatal ultrasound findings are microcephaly, lissencephaly, agenesis of corpus callosum, intracranial calcification, cerebellar atrophy, ventriculomegaly, brain hypoplasia, microophthalmia, abnormal amniotic fluid volume, abnormal cerebral blood flow, abnormal umbilical artery blood flow, hydrocephalus, intrauterine growth restriction, and arthrogryposis which are mostly CNS lesions. Pregnant women who have a traveling history in active infection areas should have serological testing for Zika virus infection. Targeted ultrasound examinations at 18-20 weeks of gestation and serial ultrasound follow-ups are also suggested. In the cases of fetal microcephaly, intracranial anatomy and extracranial abnormalities should be also carefully examined. Amniocentesis might be needed for suspected Zika virus infection, genetic abnormalities, or other congenital infection.