How is a pH test strip structured?
In principle, the pH value is measured by so-called pH indicators, which change their color specifically at a certain pH range. In their simplest form, these indicators are applied to paper and the paper is rolled into a small roll and can be torn off at any length. Paper is not suitable for use with urine or in the vagina, so the indicators are often applied to firmer paper or plastic sticks.
What pH test strips are available?
For urine, simple indicator paper can be used if the medium jet urine has been collected in a special container. Urine that has already been in the toilet cannot be used for pH measurement. Solid indicator sticks made of paper or plastic can be held directly in the urine stream.
If an elevated pH value is measured in the vagina during pregnancy, this can be an indication of leaking amniotic fluid and thus – depending on the time – also indicate that the bladder has ruptured too early. The normal vaginal pH value is relatively acidic, ranging from 3.8 to 4.4. Urine is also usually slightly acidic.
Amniotic fluid, on the other hand, has a neutral to alkaline value of 6.5 to 7. If amniotic fluid leaks during pregnancy, for example due to a rupture in the amniotic sac, the pH value in the vagina also increases. In this way, the pregnant woman herself can differentiate whether only small amounts of urine have been discharged or whether amniotic fluid is leaking from the vagina.However, during testing the values are often falsified by measurement errors or impurities.
At the doctor’s office, a test can be performed that reliably indicates whether amniotic fluid has leaked or not. In addition to testing whether amniotic fluid has leaked, pH test strips can also be used to determine the pH value of the vagina. If there is a so-called vaginal milieu disorder, i.e. if the vaginal pH is too high, bacteria can settle more easily in the vagina.
These bacterial infections are the most common reason for premature labor and premature births. If an increased pH value is measured in the vagina for more than one day, a doctor should be consulted. Even outside of pregnancy, the vaginal environment can easily be checked with a pH test strip or glove.
Even in non-pregnant women, an increased pH value in the vagina leads to an increased risk of infection. The pH value in the vagina can also increase in the case of vaginal mycosis. In principle, the pH value of saliva can be measured with any type of test strip.
Here too, it is particularly important to observe the correct application (see above). Each pH test strip discolors once it has come into contact with a liquid. The resulting color reactions are usually not reversible.
This means that after the test strip has been used once, it cannot be used again. In addition, strict attention should be paid to the package insert when storing the test strip. If the test strips are stored incorrectly, they may become unusable after a short time.
