Pregnancy-associated osteoporosis

Pregnancy-associated osteoporosis (PAO) is a rare condition where bones break (fracture) easily, around the time a woman gives birth. You may hear it called pregnancy-related osteoporosis. It most commonly affects bones in the spine, or occasionally in the hip, causing pain and disability.

These broken bones usually happen during the birth or in the next 8 to 12 weeks – and usually affect a woman's first pregnancy. But some women break bones in their second or third pregnancies, after a normal first pregnancy.

The affected bones heal in the normal way, and women usually recover and return to their usual activities. However, it can be a frightening and confusing time when bones break – both for the women affected and for their families.

What causes pregnancy-associated osteoporosis?

We don't yet know why some women suddenly develop weak bones when they are pregnant. It doesn't appear to be linked to a woman's age.

Most women who break bones while pregnant seem to have normal levels of calcium and hormones. And they don't have any underlying bone disease, such as osteogenesis imperfecta. 

Experts have suggested many possible reasons for pregnancy-associated osteoporosis, including the following.

• Pregnancy might trigger a sudden and unusual reaction in previously healthy bones.
• Normal levels of bone loss in pregnancy might lead to further bone loss in women who already have quite weak bones. However, having low bone density before getting pregnant doesn't seem to lead to faster bone loss or broken bones during or after pregnancy.

These are just suggestions and we need more research to understand why some women get pregnancy-associated osteoporosis.

If you have pregnancy-associated osteoporosis

If you have pregnancy-associated osteoporosis, you'll probably have lots of questions, such as:

• Why did my bones lose strength and break?
• Should I have a bone-strengthening treatment?
• Can I have more babies?
• Can I still breastfeed?
• How can I prevent this happening in another pregnancy?
• Will I have osteoporosis and broken bones when I'm older?

Read next:

Our booklet aims to answer some of these questions.

• • 'Pregnancy and osteoporosis' booklet

Watch our Facebook Live:

You may also like to watch a conversation between our Clinical Advisor Sarah Leyland and Professor Stuart Ralston, Chair of Rheumatology at Edinburgh University, who were joined by someone affected by this rare condition in February 2022 as part of our #BoneMatters series of events.