Free calcium ion concentration in pregnancy. A longitudinal study on 22 normal pregnant women.
302 samples from 22 normal pregnancies were frozen and kept for the analysis of free calcium ion concentration [Ca2+](7.4) at 37 degrees C and pH 7.40, after equilibration with CO2. Individual regressions were performed, and the concentration was found to increase slightly but significantly (5%, p less than 0.005) with the progress of the pregnancy. This increase excludes hypocalcemia as the cause of parathyroid overactivity during pregnancy, and a higher set point of the parathyrin (PTH) secretion is suggested.
D002118:Calcium / Q000097:blood*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D011247:Pregnancy
D002118:Calcium