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Published on: August 13, 2019
Bone physiology during pregnancy and lactation in young macaques
S M Ott1, E W Lipkin, L Newell-Morris
1Department of Medicine and Anthropology, University of Washington, Seattle, Washington 98195-6426, USA.
Summary
Adolescent pregnancy in macaques shows bone mineral loss during lactation, but bone formation increases post-weaning, restoring bone mass. This study reveals key insights into maternal bone remodeling during and after pregnancy.
Area of Science:
- Reproductive Biology
- Bone Physiology
- Primate Models
Background:
- Adolescent pregnancy presents unique physiological demands on maternal bone health.
- Understanding bone remodeling dynamics during and after pregnancy is crucial for maternal health.
- Nonhuman primate models offer valuable insights into human pregnancy-related physiological changes.
Purpose of the Study:
- To characterize bone remodeling and bone mass changes in adolescent female macaques during pregnancy, lactation, and post-weaning.
- To investigate the hormonal and mineral changes associated with these bone dynamics.
- To elucidate the mechanisms of bone loss and recovery in this model.
Main Methods:
- Longitudinal study of 125 nulliparous Macaca nemestrina through pregnancy, lactation, and post-weaning.
- Comparison with 13 nonpregnant control females.
- Measurements included whole body bone mineral, vertebral bone mineral apparent density, serum calcium, phosphate, vitamin D metabolites (25-hydroxyvitamin D, 1,25-dihydroxyvitamin D), osteocalcin, and bone histomorphometry.
Main Results:
- Whole body bone mineral increased from early to mid-pregnancy, with no change until parturition.
- Maternal bone mineral decreased by 3.0% during the first 3 months of lactation, with recovery by 3 months post-weaning.
- Vertebral bone mineral apparent density decreased during pregnancy and lactation, then increased post-weaning.
- Serum calcium, phosphate, 25-hydroxyvitamin D, and osteocalcin increased from mid-pregnancy to weaning, while 1,25-dihydroxyvitamin D decreased.
- Histomorphometry indicated increased bone formation parameters during pregnancy and weaning, suggesting decreased formation and possibly increased resorption at mid-pregnancy.
Conclusions:
- Adolescent pregnancy in macaques involves decreased bone formation and potentially increased resorption during mid-pregnancy.
- Lactation leads to significant maternal bone mineral loss in both cortical and cancellous bone.
- Enhanced bone formation post-weaning facilitates the restoration of bone mineral to control levels, highlighting adaptive recovery mechanisms.
