Q. How long should soft spots last? My friend's baby had surgery because his closed too soon!
A. I know your friend's situation has you worried about your own baby, but try to relax: Her child's condition is rare.
To answer your question, you may feel at least one soft spot on your baby's head until well past her first birthday, though they may close entirely by as soon as 9 months.
It helps to understand what soft spots are. A newborn's skull isn't solid; it's made up of six bones with spaces between them called sutures. The two places where the sutures come together, at the front and back of the head, are called fontanelles, or "soft spots." The one at the back of the head closes when a baby is 1 to 4 months old, but the front one, and the sutures around it, shouldn't fuse until 9 to 18 months.
When the bones join too soon, it causes a condition called craniosynostosis. Mild cases can result in a slightly abnormal head shape; severe ones can squelch infant brain growth, leading to problems like mental retardation, seizures, or blindness. The treatment can range from nothing to a "mold" (a helmet-like thing that guides the head into the right shape) to surgery to reopen the space between the bones.
Pediatricians routinely check babies' heads precisely so they can catch — and treat — craniosynostosis right away, which is what happened with your friend's baby.