Soft spot that doesn’t close If the soft spot stays big or doesn’t close after about a year, it is sometimes a sign of a genetic condition such as congenital hypothyroidism.
Over time, the fontanelles harden and close. The fontanelle at the back of your baby’s head usually closes by the time your baby is 2 months old. The fontanelle at the top usually closes sometime between the ages of 7 months and 18 months.
The most common causes of a large anterior fontanel or delayed fontanel closure are achondroplasia, hypothyroidism, Down syndrome, increased intracranial pressure, and rickets.
Normally, a baby’s soft spot is firm and curves in just slightly. But call your doctor right away if you notice these two (rare) signs of trouble: A fontanelle that’s dramatically sunken. This is a sign of dehydration.
Two additional fontanelles (metopic fontanelle and sagittal or third fontanelle ) can also be present in humans. In monkeys the fontanelles are nearly or completely closed at the time of birth, in apes the fontanelles are small but still present at birth, whereas in humans the fontanelles are large in newborns.
Can I hurt my baby’s brain if I touch the soft spot? Many parents worry that their baby will be injured if the soft spot is touched or brushed over. The fontanel is covered by a thick, tough membrane which protects the brain. There is absolutely no danger of damaging your baby with normal handling.
Newborn babies breathe through their noses almost exclusively unless their nasal passage is obstructed in some way. In fact, young babies — until around age 3 to 4 months — haven’t yet developed the reflex to breathe through their mouths.
A bulging fontanel means that the soft spot looks bigger than usual. The normally soft area may swell up taller than the rest of the skull. The baby’s head may appear to change shape, or the soft spot might look misshapen. Sometimes, the baby’s whole head looks bigger.
When assessing the fontanelles, use the flat pads of your fingers to palpate (gently feel) the surface of the head. Ensure you make note of any retraction or bulging, as the normal fontanelle feels firm and flat (not sunken or bulging).
The fontanelles should feel firm and very slightly curved inward to the touch. A tense or bulging fontanelle occurs when fluid builds up in the brain or the brain swells, causing increased pressure inside the skull. When the infant is crying, lying down, or vomiting, the fontanelles may look like they are bulging.
In addition to being the largest, the anterior fontanelle is also the most important clinically.  This structure offers insight into the newborn’s state of health, especially hydration and intracranial pressure status. A sunken fontanelle is primarily due to dehydration.
A tense or bulging fontanelle occurs when fluid builds up in the brain or the brain swells, causing increased pressure inside the skull. When the infant is crying, lying down, or vomiting, the fontanelles may look like they are bulging.
Most grunting is totally normal. These funny sounds are usually related to your baby’s digestion, and are a result of gas, pressure in the belly, or the production of a bowel movement. In the first few months of life, digestion is a new and difficult task. Many babies grunt from this mild discomfort.
Urinates less frequently (for infants, fewer than six wet diapers per day) Parched, dry mouth. Fewer tears when crying. Sunken soft spot of the head in an infant or toddler.