How pregnancy tests work
Even if you are not a parent yet, chances are you know what a pregnancy test looks like. Let's find out how they work.
Pharmacies carry different types of home pregnancy tests. However, they all work much the same way, by looking for the human chorionic gonadotropin (hCG) hormone which starts to develop in a woman’s system from the beginning of pregnancy and doubles every few days in the first weeks [1, 2].
Most at-home pregnancy tests are up to 99% accurate and will give a false negative result only if done incorrectly or too soon after conception [3]. A person’s best bet is to closely follow the instructions on the test and wait until they miss their period. Keep in mind that some tests can detect lower levels of hCG than others; that information is usually printed on the package.
Pregnancy can also be confirmed via a blood test. These are usually ordered if the doctor needs to know the exact levels of hCG, or if they don’t want to wait until a missed period to know if conception was achieved. These situations can be common in couples undergoing fertility treatment or who have a history of miscarriages [2].
