ALTERATIONS OF MAGNESIUM AND CALCIUM IN T HE MYOMETRIUM IN LABOR

Magnesium is commonly used in the therapy and prevention of preterm la bour. Therefore the differences of the concentrations of magnesium and its antagonist calcium were measured in the human myometrium to exami ne the interaction of labour and ionic changes. The ionic concentratio n in the myometrium of 37 patients without labour are determined and t he values are compared to the data of 26 patients in active labour. Wo men of the first group without labour had a magnesium concentration of xBAR = 4.1 mmol/kg wet weight and a calcium concentration of xBAR = 2 .9 mmol/kg wet weight. Women of the second group with active labour ha ve a singificantly lower (p<0.01) magnesium concentration (xBAR = 3.5 mmol/kg wet weight). However, the calcium level (xBAR = 2.7 mmol/kg we t weight) does not show significant differences. These results indicat e that the decrease of magnesium plays an important role in the physio logy of parturition. A low magnesium concentration in the myometrium m ight have a considerable influence on premature labour in the third tr imester of pregnancy. Therefore a prophylactic application of magnesiu m seems to be useful.