http://www.niams.nih.gov/Health_Info/Bone/Bone_Health/Pregnancy/default.asp
National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health
Both pregnancy and breastfeeding cause changes and place extra demands on a woman’s body. Some of these may have an affect on her 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 is often easily corrected. Nevertheless, taking care of one’s bone health is especially important during pregnancy and when breastfeeding – for the good health of both the mother and her baby.