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Home pregnancy test
Last reviewed: 07.07.2025
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[ How to do a pregnancy test at home?
As is known, pregnancy testing is based on the fact that a few days after conception (fertilization of the egg) the chorion cells (the embryonic part of the placenta) begin to synthesize a special hormone - human chorionic gonadotropin (hCG). It gets into the woman's urine, and there its free particles (beta subunits) can be detected using monoclonal antibodies to chorionic gonadotropin - proteins produced by B-lymphocytes of the immune system and having high sensitivity to hCG.
That is, pregnancy is determined by the coloring of the test strips as a result of a special immunochemical reaction - immunochromatography. And the test strips, or rather their membranes, are treated with a corresponding chemical composition. This composition, in addition to the dye (particles of colored latex, nanoparticles of colloidal gold or carbon) includes a compound of labeled specific monoclonal antibodies to chorionic gonadotropin.
How can a folk pregnancy test with iodine counter immunochromatography? They say that everything is very simple: when pregnancy occurs, iodine turns purple - if you drop it on paper moistened with urine. And if the woman is not pregnant, then the iodine will either not change at all, or will turn blue.
It is also suggested to monitor the behavior of a drop of iodine, which should be dropped from a pipette into a bowl of urine: when this drop immediately spreads, it should mean that the woman has not become pregnant. But if a drop of an alcohol solution of iodine lingers on the surface, then pregnancy has occurred.
Neither a chemical mechanism nor experimentally verified data regarding the reliability of this method could be found.
Pregnancy test with soda
Sodium bicarbonate (baking soda) is an alkaline salt, and the baking soda pregnancy test - apparently - takes advantage of this quality.
To conduct a soda pregnancy test, you will need half a glass of your first morning urine and a teaspoon of soda, and then all that remains is to throw the soda into the urine. The formation of hissing foam and bubbles will mean a negative result, and the precipitation without bubbles will mean a positive result.
The whole secret of this "trick" is that soda has alkaline properties, and urine is acidic. So a negative result of this "test", given the specific pH of urine, is guaranteed. Carbon dioxide and water, into which the intermediate product of the usual reaction of soda - carbonic acid - breaks down, fizz and bubble when in contact with urine acids.
Pregnancy test with potassium permanganate
The potassium permanganate pregnancy test suggested by some is based on the belief that if pregnancy occurs, urine will not change the faint pink color of the potassium permanganate solution, but suspended particles should appear in it. And if the woman is not pregnant, then when her urine is added to the potassium permanganate solution, the mixture will acquire a yellowish tint.
Potassium salt of manganese acid is a very strong oxidizer and enters into oxidation-reduction reactions with salts contained in urine. During decomposition, anions turn into cations and molecular oxygen is released, which discolors the solution of potassium permanganate. And what does pregnancy have to do with it?
Approximately the same absurdity comes from attempts to conduct a pregnancy test in the early stages using... toothpaste. It is recommended to put a sufficient amount of white toothpaste in a container with urine and wait 10 minutes. The appearance of foam in the container indicates the onset of pregnancy, everything else is considered a negative indicator.
We would like to remind you that it is the 21st century, and trying to do a pregnancy test at home using all the methods described above is simply impractical.