Question
My baby is now four and a half months old, and recently I’ve noticed that their fontanelle is slightly bulging (but not severely). I read that it could be due to intracranial hypertension, but my baby doesn’t seem to have any abnormal reactions; they are as usual. I’m not sure if this kind of bulging has any effect on the baby, and what should we do?
Answer
A baby’s anterior fontanelle appears slightly more full when the child is lying down compared to when they are sitting or standing. It is also normal for the fontanelle to bulge during crying, straining, or coughing. This can also occur when a baby is feverish due to increased blood flow and heart rate, leading to higher blood volume. In pathological conditions, increased intracranial pressure is more common, and if a baby is experiencing oxygen deficiency or asphyxia, it may lead to brain edema and an enlarged fontanelle.Brain hydrops can also cause a sunken fontanelle. The most common reason for a sunken fontanelle is dehydration within the body, such as after diarrhea or vomiting when fluids are lost without timely replenishment of water. Additionally, if a baby has been administered a large dose of diuretics, it can also cause the fontanelle to sink due to dehydration. In both cases, it is important to replenish fluids promptly for the baby to avoid electrolyte imbalances.