Previous Adolescent Pregnancy and Breastfeeding Does Not Negatively Affect Bone Mineral Density at the Age of Peak Bone Mass

To determine bone mineral density (BMD) at the age of peak bone mass in women who previously experienced pregnancy and breastfeeding during adolescence. In this retrospective study, female volunteers aged 24-30 years who were pregnant during the age of 15-19 years and have had one to two babies were recruited. All of them experienced breastfeeding without history of bone- or calcium-related problems, such as fracture or low calcium intake. BMD was determined at the femur and L1-L4 spine by dual-energy X-ray absorptiometry. We found that both volunteers who previously experienced breastfeeding and age-matched control volunteers had similar BMD at the L1-L4 spines and femora. Further analysis for site-specific changes of lumbar and femoral BMDs showed that the values of the breastfeeding group were not different from those of the control group except at L1 and L2, where BMD values were greater in breastfeeding group compared with the control group. At both femoral and vertebral sites, T- and Z-scores were apparently similar between the two groups. In addition, the BMD at peak bone mass had no significant correlation with breastfeeding duration. Teenage pregnancy and breastfeeding did not negatively affect BMD later at the age of peak bone mass. Therefore, breastfeeding can be encouraged in teenage mothers.