[Changes of osteocalcin levels in pregnant and postpartum women]

The concentration of plasma osteocalcin, or bone GLA protein (BGP), alkaline phosphatase (AKP), calcium and phosphate were measured in 142 pregnant women at various stages of pregnancy and postpartum, and also in another 47 healthy non-pregnant women as control. In contrast to the control group, plasma BGP level showed significant increase at second and third trimester (P < 0.01 and P < 0.001 respectively), with the peak level at immediate postpartum period and returned to normal in 5 days. Serum AKP level increased as pregnancy progress, and there was significant difference between the levels at the 3rd trimester and that at non-pregnant status (P < 0.01). This study demonstrated that there was marked bone metabolism changes during pregnancy, and it indicated that osteocalcin might play a role in the regulation of bone metabolism.