How big is the head circumference of a 4-month-old baby?

Patient's question:

No

Doctor's answer:

Hello, according to the question you mentioned, the head circumference of children aged 4-5 months is generally slightly more than 42-43 centimeters. Both a significantly large head circumference and a significantly small head circumference are considered abnormal. Generally, a small head circumference may be caused by delayed brain development, while a large head circumference may be due to diseases such as rickets caused by calcium deficiency or hydrocephalus.