The Zika Virus and Pregnancy

Purpose of Review Following the recent association of Zika virus with microcephaly in Brazil, there has been a multitude of studies attempting to elucidate the relationship between Zika virus infection in pregnancy and congenital anomalies. The American Congress of Obstetricians and Gynecologists (ACOG), the U.S. Centers for Disease Control and Prevention (CDC), and the Society for Maternal Fetal Medicine (SMFM) have all issued guidelines governing the screening and management of pregnant patients with Zika exposure. These guidelines have rapidly evolved as the scientific evidence supporting causation of microcephaly in cases of Zika Virus infection has continued to mount. The purpose of this article is to review the current guidelines and the available evidence on which they are based. Recent Findings A series of experiments on animals and human cell lines have demonstrated that Zika virus is neurotropic. Further, examinations of amniotic fluid, fetal tissues, and placenta have confirmed the ability of Zika virus to cross the placenta. With the currently available evidence, the CDC has recently concluded that Zika virus infection in pregnancy is a cause of microcephaly. Summary Recently, it has become clear that Zika virus infection during pregnancy is responsible for congenital brain anomalies and microcephaly in the offspring. What remains unclear is the rate of vertical transmission from mother to fetus, the risk of microcephaly, and other CNS anomalies in fetuses when maternal infection is proven and the time from exposure or infection to clinical manifestations including ultrasound anomalies. Further studies are needed to answer these important questions.