Pregnancy-associated osteoporosis was first reported more than forty years ago. At that time in 1955, there were reports of women who experienced vertebral fractures following delivery.
It appeared that if pregnancy-associated osteoporosis exists, it was probably quite rare. By 1996, eighty cases had been reported in the literature. It is difficult to adequately investigate, due to the inability to perform maternal radiologic exams. Pregnancy-associated osteoporosis tends to be identified in the postpartum period (56%) or the third trimester (41%).
Theoretically, pregnancy-associated osteoporosis is believed to occur because of the stress on maternal calcium stores and an increase in urinary calcium excretion. The body also responds to fetal calcium demands by increasing total 1,25-dihydroxyvitamin D levels. These two mechanisms are the reasons for the increased demand for calcium during pregnancy.
Physiologic changes during pregnancy include the third trimester estrogen surge and increased bone-loading due to weight gain. During pregnancy, the baby growing in its mother’s womb needs plenty of calcium to develop its skeleton. (WHO studies)
This need is especially great during the last 3 months of pregnancy. If the mother doesn’t get enough calcium, her baby will draw what it needs from the mother’s bones but most women of childbearing years are not in the habit of getting enough calcium.
There is fact in the context when we look at studies that show pregnant women absorb calcium from food and supplements better than women who are not pregnant. This is especially true during the last half of pregnancy, when the baby is growing quickly and has the greatest need for calcium. During pregnancy, more estrogen, a hormone that protects bones is produced and therefore any bone mass lost during pregnancy is typically restored within several months after the baby’s delivery.
However in recent times though there have been cases which indicate that women develop osteoporosis during pregnancy or breastfeeding, although it is rare. Transplacental calcium transfer occurs during pregnancy, especially during the last trimester. This is to meet the demands of the rapidly mineralizing fetal skeleton.
There is an obligate loss of calcium in the breast milk during lactation. Both these result in considerable stress on the bone mineral homeostasis in the mother. The maternal adaptive mechanisms to conserve calcium are different in pregnancy and lactation.
Studies have suggested that in spite of considerable changes in bone mineral metabolism during pregnancy, parity and lactation are not significantly associated with future risk for osteoporosis. However, the scenario is different in India.
The situation may not be the same as a significant proportion of pregnancies occur in the early twenties when peak bone mass is not yet achieved. Further, malnutrition, anemia and vitamin D deficiency are commonly encountered in this age group(NIN studies). This has an impact on future bone health of the mother. Loss of bone mass during lactation occurs mainly due to elevated PTHrP as well as hypo estrogenic state associated with high prolactin levels.
Current scenario in India
During puberty and adolescence, the skeleton takes up calcium avidly and builds up its reserves. This uptake of calcium into the bone is largely dependent on calcium and vitamin D nutrition, as well as exercise.
A good nutrition that is rich in calcium further helps to develop stronger bone density. It is highly advisable for girls at adolescent to have a good diet , proper exercise as this will help them to have reserves during pregnancy and for the growing needs of the fetus.
However , in India , the scenario varies. Traditionally in India, girls are not given the same social status as boys. Even though with education and knowledge, there are positive changes albeit it is not very significant but also limited to urban areas and more so in middle and high income social standings.
In low social income families and in rural parts of India , the tradition continues. Girls are not given healthy nutritious diets right from childhood. The girls are not encouraged to get proper exercise .more so in adolescence when the body is gearing for menstrual cycle.
Teen marriages are rampant which is followed by pregnancies and lactation . All these factors coupled with poor diet are responsible for bone loss during pregnancy as whatever reserve the mother has goes for the increasing demands of the fetus . The loss of calcium, poor absorption of nutrients and lack of minerals such as vitamin D all provide a major risk for osteoporosis post pregnancy.
An estimated 61% pregnant women are affected with osteoporosis in India.(NFHS 3) Studies have reported lower bone density among Indian women with osteoporotic fractures compared to their North American or European counterparts. There is a high prevalence of Vitamin d deficiency in Indian women right from their adolescence.(NIN studies)
Need for concern.
Post pregnancy osteoporosis causes fragile fracture mostly in vertebrae. The bone loss in lactating women is caused by calcium loss, decrease in estrogen level, and increase in PTHrP (parathyroid hormone related protein) level. Post pregnancy osteoporosis should be concerned, when we see a lactating woman with fragile fracture of the vertebrae.
Affects of osteoporosis are back pain, loss of height, and vertebral fractures, Hip pain and fracture of the femur are less common but not unusual. Osteoporosis is a serious public health problem, this much studies have proven. But post pregnancy osteoporosis , even though rare, has to seen in the context of public health. If osteoporosis is not treated post pregnancy it can lead to serious health issues. Osteoporosis is often called the "silent" disease, because bone loss occurs without symptomps. A common occurrence is compressionfractures of the spine. These can happen even after a seemingly normal activity, such as bending or twisting to pick up a light object. The hunchback appearance of many elderly women, sometimes called "dowager's" hump or "widow's"hump, is due to this effect of osteoporosis on the vertebrae.
There is no cure for osteoporosis but with timely and alternate treatment one can reverse the effects .there are two major ways to prevent osteoporosis
- build strong bones with exercise
- a diet rich in calcium and vitamin D
Exercising regularly builds and strengthens bones Minimize bone loss and possibly reduce the risk of broken bones. It Increases muscle strength Even if one already has osteoporosis, exercising can help maintain the bone mass. Exercise helps to maintain the amount and thickness of bones. Adequate physical activity early in life is important in reaching peak bone mass. Physical activities cause muscles and bones to work against gravity. Some examples of physical activities include
- Walking, Jogging, or running
- Stair climbing
- Jumping rope
Incorporating physical activity from early childhood ensures stronger bones throughout adult life. Young girls and adolescent girls should be encouraged to exercise right from their school days.
Proper nutrition is the one of the major prevention method for any disease. Early childhood nutrition will determine the health of an individual throughout his childhood, adolescence adult life. This is especially important for girls as in India, studies show that there is major lack of proper nutrition right from infancy. This leads to serious problems in adolescent age which is coupled with onset of menstrual cycle and prevalent teen marriages leading to early pregnancy. This leads to loss of bone density that may continue throughout adult life.