When a pregnant woman contracts Zika, she can potentially pass the virus to her unborn child, which can result in several serious birth defects, including microcephaly. Microcephaly is a condition in which a baby’s head grows much smaller than expected and results in  incomplete brain development. This condition can result in a range of developmental problems and intellectual disabilities, as well as problems with movement, vision, and hearing. Microcephaly is a lifelong condition. Though microcephaly has been commonly linked to Zika, the virus can lead to other birth defects.