Is it normal for a baby's anterior fontanelle to be sunken?

We all know that there is a soft area on the top of a newborn baby's head, just like a door. This is actually not a deformity. In medicine, it is called fontanelle. As long as the baby grows normally, it will close after a period of time and will not have any impact. So the question is, sometimes the baby's anterior fontanelle looks sunken, is this normal?

Under normal circumstances, the baby's anterior fontanelle is approximately 1.5×2 cm in size, and appears flat or slightly concave on the surface. But sometimes the swelling occurs suddenly, and the baby also has symptoms such as fever. In this case, you should see a doctor as soon as possible.

Next, let’s take a look at the symptoms of abnormal fontanelle in babies.

question:

My son is four months old. Today I suddenly found that his anterior fontanelle is sunken. Is this normal? He had a cold, fever and vomited a few days ago, but he got better after an IV drip. He is not very thin either. This is different from the information I found. Moms, do you know the reason? Is this a big deal?

answer

Although the baby's fontanelle is not big, it is a very important window for every parent to observe whether the baby is healthy or not. By observing this small window when the baby is less than 1 year old, many diseases can be discovered early, allowing the baby to be diagnosed and treated early.

Due to incomplete ossification when the baby is born, there is a diamond-shaped unclosed depression on the top of the forehead, like a "skylight" without bone, which is medically called the "fontanelle", also called the anterior fontanelle. Under normal circumstances, the baby's anterior fontanelle is approximately 1.5×2 cm in size, and appears flat or slightly concave on the surface. In the first few months after birth, the anterior fontanelle will enlarge slightly as the head circumference gradually increases. After the baby is 6 months old, the fontanelle will gradually become smaller due to the gradual ossification of the skull. When the baby is 1 to 1 and a half years old, the anterior fontanelle will basically be closed. The surface of the fontanelle is the scalp, underneath it is the meninges, and then the brain and cerebrospinal fluid. Place your finger gently on the fontanelle and you can feel the beating. This is the pulsation of the baby's cerebrospinal fluid pressure as the heartbeat and blood pressure change, consistent with the pulse. When a normal baby is sitting, the fontanelle is slightly sunken. There is a posterior fontanelle along the cranial suture. When a normally developed child is born, the posterior fontanelle is basically closed. Even if it is not closed, it will close automatically three months after birth.