Both pregnancy and breastfeeding cause changes in, and place extra demands on, women’s bodies. Some of these may affect their bones. The good news is that most women do not experience bone problems during pregnancy and breastfeeding. And if their bones are affected during these times, the problem often is corrected easily. Nevertheless, taking care of one’s bone health is especially important during pregnancy and breastfeeding, for the good health of both the mother and her baby.

During pregnancy, the baby growing in its mother’s womb needs plenty of calcium to develop its skeleton. 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. So, it is disconcerting that most women of childbearing years are not in the habit of getting enough calcium. Fortunately, pregnancy appears to help protect most women’s calcium reserves in several ways:

• 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, women produce more estrogen, a hormone that protects bones.
• Any bone mass lost during pregnancy is typically restored within several months after the baby’s delivery (or several months after breastfeeding is stopped).

Some studies suggest that pregnancy may be good for bone health overall. Some evidence suggests that the more times a woman has been pregnant (for at least 28 weeks), the greater her bone density and the lower her risk of fracture.

In some cases, women develop osteoporosis during pregnancy or breastfeeding, although this is rare. Osteoporosis is bone loss that is serious enough to result in fragile bones and increased risk of fracture.

In many cases, women who develop osteoporosis during pregnancy or breastfeeding will recover lost bone after childbirth or after they stop breastfeeding. It is less clear whether teenage mothers can recover lost bone and go on to optimize their bone mass.

Teenage mothers may be at especially high risk for bone loss during pregnancy and for osteoporosis later in life. Unlike older women, teenage mothers are still building much of their own total bone mass. The unborn baby’s need to develop its skeleton may compete with the young mother’s need for calcium to build her own bones, compromising her ability to achieve optimal bone mass that will help protect her from osteoporosis later in life. To minimize any bone loss, pregnant teens should be especially careful to get enough calcium during pregnancy and breastfeeding.

Studies have shown that the majority of women with pregnancy-associated osteoporosis are breastfeeding at the time of diagnosis. Duration of lactation has ranged from one week to seven months. Bone loss tend to be greatest in skeletal sites with the highest concentration of tarbecular bone. Reductions in bone density by three to five percent at the lumbar spine are common.

Two physiologic occurrences may be responsible for bone loss during lactation. First, there is an increased calcium demand from maternal bone. This demand varies from woman to woman based on the amount of breastmilk produced and upon the duration of lactation. Secondly, because of elevated prolactin levels, women who breastfeed tend to be in a hypoestrogenic state.

Through significant amounts of bone mineral can be lost during breastfeeding, the loss of bone tends to be transient. Studies have consistently shown significant trends in bone loss during lactation, with full recovery of bone density by six months after weaning. Kalwarf and Specker reported women who experience an earlier resumption of menses lose less bone during lactation and recover more bone after weaning. Other studies have identified similar trends in bone loss, with full recovery of bone density by six months following the cessation of breastfeeding.

An important element used in producing milk is calcium. Because women lose calcium while lactating, some health professionals have mistakenly assumed an increased risk of osteoporosis for women who breastfeed. However, current studies show that after weaning their children, breastfeeding mothers’ bone density returns to prepregnancy or even higher levels (Sowers 1995). In the longterm, lactation may actually result in stronger bones and reduced risk of osteoporosis. In fact, recent studies have confirmed that women who did not breastfeed have a higher risk of hip fractures after menopause.

The mother might also want to have her Vit. D levels checked. You can take all the calcium in the world, but if your vitamin D levels are inadequate, you can still have osteopenia. Many people are Vitamin D deficient.

Here is a link to the Harvard School of Public Health, and very good article about Vitamin D with references at the end.

http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/vitamin-d/

References :

Cumming, R.G. et al. Breastfeeding and other reproductive factors and the risk of hip fractures in elderly women. Int J Epidemiol 1993; 22(4):684-91.

Chan, G.M. et al. Growth and bone mineralization of normal breast-fed infants and the effects of lactation on maternal bone mineral status. Am J Clin Nutr 1982; 36:438-43.

Kalkwarf, H.J. et al. The effect of calcium supplementation on bone density during lactation and after weaning. N Engl J Med 1997; 337(8):523-28.

Kalkwarf, H.J. et al. Intestinal calcium absorption of women during lactation and after weaning. Am J Clin Nutr 1996; 63(4):526-31.

Kalkwarf, H.J. et al. Bone mineral loss during lactation and recovery after weaning. Obstet Gynecol 1995; 86(1):26-32.

Specker, B.L. et al. Changes in calcium homeostasis over the first year postpartum: effect of lactation and weaning. Obstet Gynecol 1991; 78(1):56-62.

Laskey, M.A. & Prentice A. Bone mineral changes during and after lactation. Obstet Gynecol 1999-10; 94(4):608-15

Sowers, M.F. Changes in bone density with lactation. JAMA 1993; 269(24):3130-35.

Tags: bone density, bone mass decrease, lactation, osteopenia, Osteoporosis