Abstract
Calcium regulating hormones have not been studied in relation to bone mineral content (BMC) during pregnancy. We hypothesized that bone mineral content would be correlated with calcitonin (CT) concentrations, since CT is considered a hormone protective of maternal skeleton during times of Ca stress; BMC also would be maintained in pregnancy because of elevation of 1,25(OH)2 vit. D levels, which promotes bone Ca stores by increasing intestinal Ca absorption. 11 normal pregnancies in middle class women between 25-35 yrs. old were studied prospectively. Blood samples were drawn for analysis of iCa (ion specific electrode), 1,25(OH)2 vit. D (HPLC, protein binding assay N= 29 ± SD 6 pg/ml) & CT (radioimmunoassay, 1-32 CT); monthly BMC were measured by photon absorptiometry. BMC (1/3 radius) was .787 ± SE .033 gm/cm, .781 ± .033, .819 ± .024 & .795 ± .027 at 8-11, 13-16, 23-27 & 33-37 wks (no significant change). iCa was 3.9 ± 1.14 mg/dl, 4.7 ± 1.02, 4.6 ± 1.01, 4.7 ± 1.00 (no significant change). 1,25(OH)2D was elevated 57 ± 1, (p<.001 vs. non-pregnant), 72 ± 1, 64 ± 1, 91 ± 1, (p < .1). CT was 12 ± 1 pg/ml, rose to 18 + 1, 29 + 1, 32 + 1, (p< .001). BMC was not correlated with iCa or 1,25(OH)2D; BMC was correlated with CT, after 12 wks. (r = .42, p < .04). Thus, bone mineral content is maintained during normal pregnancy; 1,25(OH)2D is elevated early in pregnancy but not correlated with BMC; calcitonin rises > 12 wks. of pregnancy & correlates with BMC. We speculate that rises of calcitonin during pregnancy protects the maternal skeleton, & elevations of 1,25(OH)2 vitamin D restore Ca balance during a period of calcium stress.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Schutzman, J., Steichen, J., Neumann, V. et al. STABLE BONE MINERAL CONTENT ASSOCIATED WITH RISES IN CALCITONIN & 1,25(OH)2 VIT. D IN NORMAL PREGNANCY. Pediatr Res 18 (Suppl 4), 177 (1984). https://doi.org/10.1203/00006450-198404001-00502
Issue Date:
DOI: https://doi.org/10.1203/00006450-198404001-00502