MAGNESIUM AND CALCIUM-CONCENTRATION IN THE PREGNANT AND NONPREGNANT MYOMETRIUM

Objectives: To investigate the effect of labor on the magnesium and ca lcium concentrations in the human myometrium and to compare them with the concentrations in the non-pregnant uterus. Method: Samples of the isthmic part of the uterus were taken from 42 patients not in labor, 3 1 patients in regular labor during a cesarean section, and 37 premenop ausal patients on whom a hysterectomy was performed. Results: (i) The magnesium concentration dropped significantly during labor; (ii) the c alcium concentration in the tissue showed no significant changes durin g labor; (iii) the magnesium and calcium concentrations were significa ntly higher during pregnancy; (iv) the distribution of electrolytes in the myometrium differed significantly in the corpus, isthmus and cerv ix uteri. Conclusions: The electrolyte concentration in the myometrium depends on the place of removal. A low magnesium concentration in the pregnant human myometrium could be a cause of premature labor.