a cause for concern but in twenty four eighteen no one knew how dangerous the car really was. a few months later and autumn twenty fifteen hundreds of babies in brazil were born with cranial deformities they had microcephaly a malformation of the brain that starts in the early stages of pregnancy. do or do law the cells that form the brain start to multiply between the six than tenth week as the pregnancy was that even fraction occurs during the critical weeks of the first trimester there is a big risk that the brain will not develop properly and it will be so was young when a baby's head is of the normal size is because the brain develops and pushes up the skull and you have the normal contour of the skull if there's anything that interferes with that destroys that process the brain doesn't develop right in the