Amniotic fluid pH-value | Amniotic fluid

Amniotic fluid pH-value

Amniocentesis is a puncture of the amniotic sac, which can usually be performed in women from the 13th week of pregnancy. First the position of the child is determined with the help of an ultrasound and then a fine needle is inserted through the abdominal wall and further through the uterus, so that a small amount of amniotic fluid can be taken. From the cells of the child, information about possible hereditary diseases, neurological defects or chromosomal anomalies such as Down syndrome is obtained.

In addition, parameters such as the ph-value, i.e. the acidity of the amniotic fluid, can also be determined with this examination. Amniotic fluid normally has a pH value of 6.5-7, deviations may indicate a reduced oxygen supply to the child or a bacterial infection. The pH value of the amniotic fluid differs significantly from that of much more acidic urine, so that in case of doubt, the pregnant women themselves can use rapid tests to determine whether small amounts of urine have been passed, which is not uncommon in a progressive pregnancy, or whether amniotic fluid has leaked in the course of a premature rupture of the bladder.

Test strips to determine the bubble burst

The bursting of the amniotic sac is known as a rupture of the amniotic sac, which usually occurs shortly before birth. However, due to ascending infections or extreme stress as in multiple pregnancies, the amniotic sac can burst several weeks before the calculated date of birth. A very safe test that the gynaecologist carries out to determine the rupture of the bladder is the determination of IGF1, a fetal protein.

If the test is positive, amniotic fluid must have leaked from the amniotic sac, causing it to burst or at least rupture.It is important to differentiate between leaked amniotic fluid and urine, because in the later months of pregnancy the pelvic floor muscles often become increasingly weak, which can result in slight incontinence. The difficulty in diagnosis also arises from the fact that the quantities of amniotic fluid are often too small for a reliable diagnosis. An older test that pregnant women can also perform at home themselves works with litmus paper.

Litmus is a plant dye that changes color differently depending on the ph-value of the substance applied and thus functions as an acid-base indicator. With the slightly alkaline amniotic fluid, litmus paper turns blue, whereas it reacts red with the weakly acidic vaginal secretion. In addition, there is a large selection of freely available test strips in the pharmacy, also in the form of cotton swabs or gloves, which all determine the pH value in the vagina and can thus detect a premature rupture of the bladder.