Related Experiment Video
Updated: Aug 21, 2026

Culturing and Measuring Fetal and Newborn Murine Long Bones
Published on: April 26, 2019
Bone turnover from early pregnancy to postweaning
Agneta Akesson1, Marie Vahter, Marika Berglund
1Institute of Environmental Medicine, Division of Metals and Health, Karolinska Institutet, Stockholm, Sweden. Agneta.Akesson@imm.ki.se
Background:
To elucidate the sequences of changes in bone metabolism and bone density during pregnancy, lactation and postweaning.
Methods:
Women were recruited (n = 254) in early pregnancy and followed for 2 years. Markers of bone formation (osteocalcin) and resorption (NTx) were measured at five occasions. Bone mineral density (BMD) of whole-body and lumbar spine L1-L4 (DXA) and ultrasonography of os calcis were measured in a subgroup (n = 14).
Results:
NTx appeared bone specific in comparison to pyridinolines. NTx started to increase early in pregnancy and remained elevated during lactation (p < 0.001). Osteocalcin was low during pregnancy, but peaked during lactation (p < 0.018). The subsequent decrease was associated with time since resumption of menses (r2 = 0.23; p < 0.001). There was indication of a decrease in calcaneal bone mass during pregnancy and an evident decrease in lumbar spine (p = 0.041) and os calcis (p = 0.037) during lactation. No detectable decrease was identified in whole-body BMD (p = 0.090) during lactation, but in general, BMD was higher in whole-body (1.9%) and lumbar spine (6.6%) 18 months postpartum than during puerperium (p = 0.003).
Conclusion:
According to the bone metabolic markers, bone resorption increased early in pregnancy and remained elevated over lactation, while bone formation increased during lactation, probably regulated by mechanisms associated with absence of menses. The high metabolic bone turnover during late pregnancy and lactation lead to a decline in cancellous bone mass during lactation, but this seemed beneficial for BMD postweaning.
Related Concept Videos
Bone Formation by Intramembranous Ossification
The process begins when mesenchymal cells in the embryonic skeleton gather together and differentiate into osteogenic cells, which then develop into...
Bone Formation by Endochondral Ossification
Changes in the Appendicular Skeleton with Age
Initially, the limb buds consist of a core of mesenchyme covered by a layer of ectoderm. The ectoderm at the end of the limb bud thickens to form a narrow crest called the apical ectodermal ridge. This ridge stimulates the underlying...
Bone Remodeling
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...

