Ultrasonographic bone velocity in pregnancy: a longitudinal study.

Objective: Longitudinal changes in bone mass were evaluated with use of ultrasonography and bone remodeling markers in 40 normal pregnant women in relation to their calcium intake.
Study Design: The study took place at the University of Alcalá Hospital in Madrid. Biochemical markers of bone remodeling and ultrasonographic bone propagation velocity in the proximal phalanxes of fingers 2 to 5 were measured in all three trimesters of pregnancy. Wilcoxon, unpaired and paired t tests, and analysis of variance were used.
Results: Ultrasonographic bone propagation velocity (meters per second) was lower in the second and third trimesters of pregnancy (p < 0.0001) compared with the respective preceding trimesters and in the third trimester in the overall group of pregnant women. Tartrate-resistant acid phosphatase and alkaline phosphatase levels increased significantly (p < 0.0001) in parallel with the ultrasonographic bone propagation velocity decrease.
Conclusions: Gestation was accompanied by a reduction in ultrasonographic bone propagation velocity that was greater in women with low calcium intake.