How is microcephaly diagnosed?

Microcephaly can sometimes be diagnosed before birth by prenatal ultrasound. In order to make the diagnosis while the baby is still in the womb, the ultrasound should be done late in the second trimester or in the third trimester.

After the baby is born, microcephaly can be diagnosed by measuring the baby’s head circumference (all the way around) and comparing it with normal head sizes of newborns. The doctor will also perform a complete physical examination and obtain a complete prenatal and birth history of the child. The doctor might ask the parents about developmental milestones such as crawling and walking, since microcephaly is often accompanied by intellectual disabilities.

Last reviewed by a Cleveland Clinic medical professional on 01/09/2019.


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