http://www.bbc.com/news/health-35435684
"...
But in the remainder of cases, the infant's brain
may not have developed properly during pregnancy
or may have stopped growing in the first years of
life. These children may experience a range of
problems, like developmental delays, intellectual
deficits or hearing loss.
The consequences can vary widely..."
http://www.nytimes.com/interactive/2016/health/what-is-zika-virus.html