Correlations between PRL and chloride, sodium, potassium and calcium in amniotic fluid.

The concentration of prolactin in amniotic fluid from 91 pregnant women (Group I: 51 specimens obtained at 15th-20th week of gestation; Group II: 40 specimens at term) has been correlated with the amniotic fluid concentrations of calcium, of the ions sodium, chloride, and potassium, and with the clinical data. When the week of gestation in multiple regression analyses was predetermined for inclusion in the first step, the amniotic prolactin concentration was found to be significantly correlated with sodium or chloride in both groups and the correlation coefficients in the two groups were alike. The correlation coefficients of potassium and of calcium differed between the two groups and no general pattern could be detected. The results indicate that the amniotic sodium and chloride concentrations could be of importance for the regulation of the amniotic prolactin concentration.