Are my baby’s bones soft?
What starts as soft tissue becomes the skeleton of your baby.
Before you are even noticeably pregnant, your baby has the basic template of its bones, made of soft fibre and cartilage. Ossification is the gradual transition of this framework to hard bone. By week 12 of your pregnancy the basic development of your baby’s bones are complete – for the next 6 months your baby’s bones will grow into hard bone and all ossification will take place before your baby is born.
There are two areas that stay soft, the fontanelles of the skull, one on the front and one further back on your baby’s head. The function of these soft spots is to enable your baby’s skull to flex during birth. The soft spot at the back takes about 4 months to close after the birth, but the front fontanelle takes 9 – 18 months to close, allowing the head to grow easily.