Women who are infected with the Zika virus during pregnancy have an increased risk of miscarriage, preterm birth and stillbirth. Zika virus infection during pregnancy also increases the risk of serious birth defects in infants (congenital Zika syndrome), including:
- A much smaller than normal brain and head size (mirocephaly), with a partly collapsed skull
- Brain damage and reduced brain tissue
- Eye damage
- Joint problems, including limited motion
- Reduced body movement due to too much muscle tone after birth
In adults, infection with the Zika virus may cause brain or nervous system complications, such as Guillain-Barre syndrome, even in people who never show symptoms of infection.