Amniotic fluid is mildly basic (pH 7.1-7.3) compared to normal vaginal secretions which are acidic (pH 4.5-6) and will turn the nitrazine paper from orange to dark blue.
Amniotic fluid is mildly basic (pH 7.1) compared to normal vaginal secretions. These normal vaginal secretions are acidic (pH 4.5). These normal vaginal secretions will turn the nitrazine paper from orange to dark blue. PH 4.5 is 6. PH 7.1 is 7.3.