Today, about eight out of ten women learn about their pregnancy through the self-test. Even though the meaning of the pregnancy test was initially heavily criticized, today it is inconceivable from everyday life.
The basis of all pregnancy tests then as now is the measurement of the pregnancy hormone beta-HCG. A distinction is made between urine tests and blood tests. In the blood, the beta-HCG detection succeeds earlier than in urine.
Just like ovulation tests, the concentration of beta-HCG is usually greatest in the morning urine. In the first few weeks, the beta-HCG concentration in the blood increases steadily and doubles approximately every two days. The maximum is reached approximately between the 8th and 12th week of pregnancy. After that, the beta-HCG in the blood decreases, so that from about the 20th week of pregnancy, the urine tests are only very weakly positive.