LEVELS OF ALDOSTERONE AND VASOPRESSIN IN THE AMNIOTIC FLUID AND IN THE URINE OF NEWBRONS

Recently we reported about a highly stimulated renin-angiotensin-aldosterone-system (RAAS) in newborns without elevation of vasopressin (ADH) levels. In the following study we examined aldosterone (ALDO),ADH, electrolytes, creatinine and osmolality in 53 amniotic fluid samples and in urines of premature and mature newborns. Results: In all amniotic fluid samples ALDO and ADH were detectable. ADH levels were in the same range in amniotic fluids as in urines collected at the first day of life. (17 pg/ml vs. 10 pg/ml) In contrast ALDO levels in the amniotic fluid were 40 times lower than levels in urines. (37ng% vs.1280 ng%). Hormone concentrations were not correlated to fetal age, electrolytes, creatinine and osmolality in amniotic fluid. Conclusion: In the 17th week of gestation the human fetus is able to produce ADH in a similiar amount as in the early postnatal life. But Aldo levels in the amniotic fluid are significantly lower than in the urines of newborns. This may reflect the onset of stimulation of RAAS in the early postnatal life.