A Look at Pregnancy- and Lactation-Associated Osteoporosis (PLO)

Osteoporosis is a rheumatological disorder common in postmenopausal women. Osteoporosis is implicated in the loss of bone strength in women aged 50 years and above. It may cause morbidity later in life. However, osteoporosis has not been well studied in premenopausal women. Pregnancy- and lactation-associated osteoporosis is a rare condition linked to pregnancy. The disorder primarily affects the vertebrae bones, hips, ribs and pubic rami. Osteoporosis bears the risk of fractures, and a preemptive diagnosis and treatment can significantly improve the affected person’s quality of life.

During pregnancy, the growing fetus requires 30 grams of calcium for skeletal development. During lactation, 200 milligrams of calcium is secreted into breast milk daily. The mother usually acquires all this calcium by doubling the intestinal absorption rate. Sometimes, the calcium from the diet may be insufficient to satisfy the fetal growth requirements, forcing the mother’s body toward bone resorption, which lowers the mother’s calcium reserves. PLO affects four to eight women per million in a population.

Pathophysiology of PLO

Osteoporosis refers to porous bones. Osteoporosis causes decreased bone density and reduced quality of bone architecture. Typically, healthy bone has tiny pores and appears to look like a honeycomb when observed under a microscope. When you have osteoporosis, the pores become more prominent, making bones fragile and brittle.

Your bones are the body’s most extensive reserve for calcium. Bones have cells called osteoclasts that work to maintain the health and wellbeing of bones. Osteoclasts are also involved in bone resorption. When the body lacks calcium from the diet, or when there is a problem in absorption or regulation of calcium levels in the body, calcium is removed from bones. The latter may lead to reduced bone density, thus causing osteoporosis.

How Does Pregnancy- and Lactation-Associated Osteoporosis Present?

Pregnancy- and lactation-associated osteoporosis (PLO) occurs mainly in women in their first pregnancy. PLO occurs mainly in the third trimester of pregnancy when the fetal calcium requirements are 30 grams of calcium daily. While pregnancy is not a risk factor for osteoporosis, low dietary calcium during pregnancy may predispose you to PLO.

Osteoporosis is diagnosed mainly after the occurrence of fractures. In PLO, because of increased weight to the lumbar spine (your lower back) due to pregnancy, the lumber bones may get fractures leading to disabling lower back pain. Note that this lower back pain does not respond to common painkillers. Other women may notice a loss in vertebral height. Quite rarely, you may experience fractures of other bones such as pelvic and hip bones.

Risk Factors for PLO

Even though Pregnancy-and lactation-associated osteoporosis is rare, certain factors may predispose pregnant women to it:

• Women who are pregnant for the first time
• Women with PLO or fractures reported by first-degree family members
• Women with a history of osteoporosis
• Vitamin D deficiency and low calcium intake in diet
• Women with a low body mass index
• Reduced physical activity
• Certain prescription medication such as anticoagulants (blood thinners) and anti-acids (proton-pump-inhibitors)
• Smoking
• Women with increased rates of bone turnover
• Elevated hormone levels such as elevated parathyroid hormone-related protein

Diagnosing PLO

While pregnant, you should visit your gynecologist for antenatal care. When you are in your third trimester, look out for the signs mentioned above, such as disabling lower back pain and reduced spinal height. When you present with such symptoms, your gynecologist will refer you to an orthopedic surgeon. The orthopedic surgeon may require imaging of your lower back and may ask for blood calcium levels and tests to determine bone density.

Treating PLO

When you are diagnosed with pregnancy- and-lactation-associated osteoporosis, your doctor may offer some medication or supplements or ask that you stop breastfeeding your infant.

The medication or supplements may include the following:

• Bisphosphonates to improve your phosphorous and calcium levels
• Vitamin D and calcium supplements

Preventing PLO While Pregnant

While pregnant, you must get proper nutrition for yourself and your growing fetus. A regular and balanced diet rich in calcium, magnesium and zinc is essential for good health. A healthy lifestyle and regular exercise are also suitable for you when you are pregnant.

Pregnancy- and lactation-associated osteoporosis is a rare condition affecting women in the third trimester of the first pregnancy. When attempting to get pregnant, it is prudent to discuss all your risk factors with your doctor to avoid PLO. All forms of osteoporosis can be treated if diagnosed early.