Baby Talk: Understanding the birds and the bees of a baby’s bones

Question: Do babies have bones?

Answer: Yes, they do. However most of their bones are the building blocks for future bones.

Babies are born with around 300 cartilage parts that will eventually turn into 209 bones. Cartilage is dense connective tissue. This cartilage turns into hard bone through a process called ossification. Ossification is the process the body goes through when it turns a tissue into bone.

A good example of cartilage that becomes bone is the patella, or the knee cap. The cartilage that will eventually become the patella starts to form while the baby is developing in the mother’s uterus, around the seventh and eighth week of the pregnancy.

Babies are a work in progress from the beginning. When you put your baby on his/her tummy for play time, they push against the floor with their arms and legs to pull themselves up. They are also stimulating their cartilage to begin the ossification process.

At around 6 to 7 months of age, a baby will begin to crawl. Not all babies crawl — some actually go from sitting to standing to walking.

However, the majority of babies do crawl. They start by getting up on their hands and knees and rock back and forth. The pressure of putting their hands and knees on the ground is contributing to the ossification process.

Everything a baby does has a purpose. It is an amazing thing to watch the baby master the art of crawling forwards. Thank goodness their little patellas are flexible enough to tolerate all that crawling around.

What makes the baby stand up to walk? Babies are actually born with a walking reflex. It lasts for a few months and then disappears and comes back around as a child approaches their first birthday.

Our bones have growth plates on each end of our long bones. As a child grows these growth plates go from tissue to hard bone. For girls they typically show signs of an ossified kneecap around 3 years of age. Boys will have an ossified knee cap around 4 to 5 years.

This is why it is so important that children engage in age-appropriate activities. The growth plates can be damaged during these formative years and cause a lifetime of pain.

Our bones continue to grow through our adolescence. It is believed we actually continue to build our bones into our early twenties. Then as we age we start to lose our bone mass. Weight bearing exercise and eating foods rich in calcium help us maintain bone mass that our bodies worked so hard to develop when we were babies.

The human body is amazing.

Katie Powers, R.N., is a board-certified lactation consultant and perinatal educator at Manatee Memorial Hospital’s Family BirthPlace. Her column appears every other week in Healthy Living in the Bradenton Herald. Contact her at katie.powers@mmhhs.com.