I would like to know the principle of a pregnancy test, so my question is: How a pregnancy test works?

Question

To be more specific, I would like to know the biological process of it. The paper is treated? With what? What is the biochemical reaction?

Answer 1

The test detects the hormone level of HCG, which happens when you get pregnant. This level is highest in the morning before you pee, that's why they say to take the test first thing...then it is most accurate. So, you pee on the stick, it then turns colors, or makes lines based on the HCG level.

Answer 2

When you are pregnant, your body develops a hormone called Hcg. This hormone, among others, assists your developing baby throughout your pregnancy. This hormone is ONLY present when you are pregnant. When you urinate on a test / dip a test stick into urine, the test works to detect whether that hormone is present. Some say it is best to do it in the morning during very early stages of pregnancy. Reason being: you've not been pregnant long enough to store large amounts of the hormone. In the morning, you have some extra stored in your urine because you not expelled any throughout the night. This is all also the reason that one must wait a bit to even take a test from the time of conception. Once again, your body takes time to go through cycles and begin its storage and preparation for the baby and its womb. I hope I worded this all where it's understandable.

Answer 3

Human chorionic gonadotrophin (HCG) is a hormone only secreted and found in pregnancy. Both in blood and urine.

Pregnancy test has kits which look for HCG in urine.

If you rare asking about how the kits find out the HCG .... long story and complicated. It has to do with immunoglobulins which are fixed on a piece of plastic and when HCG is present .... it forms blue band.

Hope this answers your question.

Answer 4

It tests for specific hormone levels:

[edit] Chemical markers
The earliest test for pregnancy is a rosette inhibition assay for early pregnancy factor (EPF). EPF can be detected in blood within 48 hours of fertilization. However, testing for EPF is expensive and time consuming.

All commercially available tests for pregnancy look for the presence of the beta subunit of hCG or human chorionic gonadotropin in the blood or urine. They are usually performed after a missed menstruation or 2-3 weeks after ovulation.

read more about it:
http://en.wikipedia.org/wiki/Pregnancy_tests

Answer 5

pregnancy tests look for the presence of the beta subunit of hCG or human chorionic gonadotropin in the blood or urine. Usually the tests work for the detection of HCG

Answer 6

It tests for any amount of the "pregnancy hormone", HcG in your urine. This hormone only shows up when pregnant.

Answer 7

When you conceive your hormones tell your body that you are pregnant so that it can start to prepare (and to stop your periods). It is these hormones that the pregnancy test detects.

Answer 8

when you become pregnant....your body makes different chemicals ..for the baby.. and you stopo getting rid of eggs and nutrients cause they go to the baby.. what a pregnancy test does is detect the lack of certain chemicals or the excess of some in your pee. .. that signifies you are pregnant....are you?? if your are congrats

Answer 9

It has a strip inside that detects the hormone HCG in urine. It really is interesting if you open one up and look inside.

Answer 10

most of them react to the hormone HCG that is detectable through your urine. Women produce this hormone when they are pregnant.