microcephaly
noun [ U ] anatomy, medical specialized uk/ˌmaɪ.krəʊ.ˈsef.ə.li/ us/ˌmaɪ.krəʊ.ˈsef.ə.li/
小头，小头畸形
the state of having a head that is smaller than normal, because the brain has not developed normally
There has recently been a large increase in cases of microcephaly, potentially linked to the Zika virus. 最近小头畸形病例大量增加，可能与寨卡病毒有关。