According to a study conducted by the United States Center for Disease Control and Prevention (CDC), babies who appear normal at birth but whose mothers were infected by the virus have subsequently developed growth problems.
This study is the first to show that symptoms develop after birth: “Microcephaly may not be evident at birth but subsequently develops with underlying cerebral anomalies”.
The development of the head in babies with microcephaly is abnormally slow. Neurological problems are also apparent with evidence of a smaller skull and brain. According to the study, out of thirteen children born to mothers infected with the virus in Brazil, eleven showed signs of microcephaly after they were born. Moreover, seven of the thirteen children were affected by epilepsy and all had “motor problems associated with cerebral paralysis”.
Scientists have noted that the study does not necessarily show the rate at which microcephaly can develop after birth.