There are a lot of claims on the internet (like this one) that it is possible to test for pregnancy by just putting sugar in a glass and urinating on it. The hormones in the urine supposedly cause the sugar to clump. There are endless variations on it, using baking powder, toothpaste, vinegar, bleach or other household products.
Is there any scientific evidence that such tests work, or do not work?
If they do work, how well do they work, and why are they not adopted by mainstream pharma, and advocated by physicians?