When does the baby's fontanelle close?

Every baby has two fontanelles, front and back. Generally speaking, the front fontanelle will close no later than 2 years old, and the back fontanelle will usually close at 4 months old. As parents, there is no need to worry about the closure of the fontanelles too early. An unclosed fontanelle leaves space for the baby's brain development. Of course, there are also physiological problems with fontanelle closure, and the cause of this situation is often pathological.

Many parents will find that every time they take their baby for a physical examination, the doctor will check the condition and closure of the baby's fontanelle.

But there is one thing parents need to understand: the later the fontanelle closes, the better!

The closure of the fontanelle (especially the anterior fontanelle) is indeed related to the development of the brain and skull, but no research has shown that the later the baby's fontanelle closes, the better.

The closure time of the baby's posterior fontanelle generally does not exceed 3 months after birth; the closure time of the anterior fontanelle generally does not exceed 24 months after birth. As long as it is within this range, it is normal.

Pathological conditions:

Of course, there are some pathological conditions in which the fontanelle closes too early or too late.

① If the anterior fontanelle is bulging and tense, intracranial lesions should be considered in combination with other symptoms; however, some drugs or high fever can also cause a bulging anterior fontanelle, so parents need to observe closely.

② If the anterior fontanelle is sunken, vomiting or diarrhea occurs, and there is little urine, dehydration should be considered.

③The early or late closure of the anterior fontanelle is also a pathological condition: early closure is more common in microcephaly, while late closure is more common in rickets, cretinism, hydrocephalus, and central nervous system infection.

Baby, don't worry about these situations

① For a few babies, when they are 5-6 months old, the fontanelle is only the size of a fingertip and seems to be about to close, but in fact it has not ossified. This situation does not belong to premature closure.

② As long as the head circumference of a full-term newborn is not less than 33-34 cm at birth, not less than 46 cm at one year old, and not less than 47-48 cm at two years old, it is normal and there is no need to worry.