During a well-child exam, which measurement is taken to determine if a child has microcephaly?

To determine if a child has microcephaly, the measurement taken is head circumference. Microcephaly is a condition where a child's head is significantly smaller than expected for their age and sex, which can be indicative of abnormal brain development or other health issues. During a well-child exam, measuring head circumference allows healthcare providers to assess whether a child's head size is within the normal growth range for their age. This measurement is critical because it offers insights into the child's neurological development and can be used to monitor for potential developmental delays. Other measurements, such as weight and height, are important for overall growth assessment but do not specifically indicate issues related to head size or brain development.