What is PAO?

What is Pregnancy-Associated Osteoporosis (PAO)?

• Pregnancy Associated Osteoporosis is a rare condition that affects women during pregnancy, after delivery (postpartum period) or during breastfeeding (lactation).

• Women with this condition can have weaker bones and sometimes break bones (fracture) more easily. Unfortunately, some women can break bones with little or no force.

• The fractures can affect any part of the skeleton, but they most commonly affect the spine. Spinal fractures can cause severe back pain, height loss (inches) or a change in the shape of their back.

• The pain is often severe and can make it more difficult for women to care for their newborn baby/ies and themselves.

• The fractures can happen at any point in pregnancy or after delivery, but they are most common in the last trimester, during childbirth or in the first 12 weeks after delivery.

• The condition can also be called Pregnancy and Lactation Associated Osteoporosis (PLO/PLAO).

• Transient osteoporosis of the hip (TOH) is a rare condition that can affect women during late pregnancy or while breastfeeding. It is different from PAO, though some women may be diagnosed with both. TOH typically causes hip pain, resolves on its own, and usually doesn’t affect long-term quality of life. For support, consider joining the Transient Osteoporosis Patients Support Group on Facebook.

How common is PAO?

The true incidence of PAO is unclear, but it is thought to affect between 4 in 100,000 and 7 in 100,000 women during pregnancy or shortly after childbirth.

What causes PAO?

• The causes of PAO are not fully understood yet, but research teams are looking into this.

• All women experience loss of bone from the skeleton during pregnancy and breastfeeding, but this is usually regained naturally after weaning and does not cause issues.

• It is thought that women with PAO may either:

  • Experience a greater loss of bone than normal, and/or

  • Enter pregnancy with a low bone mass, making them more susceptible to the effects of bone loss.

What are the known risk factors for development of PAO?

*In most cases, PAO presents out of the blue in women with no known risk factors.

Possible risk factors that could increase the risk of developing PAO include:

• Breaking bones easily or with little force prior to pregnancy

• Diagnosis of osteoporosis or a genetic bone condition before becoming pregnant

• A family history of osteoporosis

• Treatment with blood thinning drugs (e.g. Heparin)

There are a number of risk factors for the development of osteoporosis in general. These have not been proven to be linked to PAO but might be expected to increase the risk of PAO by reducing bone mass. These include, but are not limited to:

• Steroid use for an extended period (more than 3 months)

• Low weight (low BMI), particularly if your periods stopped whilst your weight was low

• Inflammatory conditions (e.g. joint conditions like rheumatoid arthritis or bowel conditions like Crohn’s disease)

• Low activity levels (e.g. being bed bound or using a wheelchair for extended periods of time)