How long does it take for a newborn's soft spot on their head to harden or grow in?

Not Medical Advice: The soft spots on baby's head are known as fontanelles. They are located mainly at the top, back, and sides of the head. Like the sutures, fontanelles harden over time and become closed, solid bony areas. The fontanelle in the back of the head (posterior fontanelle) most often closes by the time an infant is 1 to 2 months old. The fontanelle at the top of the head (anterior fontanelle) most often closes between 7 to 19 months. Always keep an eye on your baby's fontanelles, as they can give important clues to the state of her health. Sunken fontanelles may be a sign of dehydration. Bulging fontanelles can be a symptom of a serious illness, such as meningitis. It can be hard to judge, though, so if you are unsure about whether your baby's fontanelles look normal, take her to your GP. Being a new parent can be a very difficult job. Once home, you frantically realize you have no idea what you're doing! Check out some tips that can help even the most nervous first-time parents feel confident about caring for a newborn in no time at Kidshealth.org.