What hormonal change is typically identified in the diagnosis of pregnancy?

In the diagnosis of pregnancy, the detection of increased levels of human chorionic gonadotropin (hCG) is a key indicator. hCG is a hormone produced by the placenta shortly after implantation. Its primary role in early pregnancy is to maintain the corpus luteum, which in turn produces progesterone to support the uterine lining and promote a suitable environment for the developing fetus.

The increase in hCG can typically be measured through blood tests and urine tests, forming the basis for most home pregnancy tests. The levels of hCG rise rapidly in the first few weeks of pregnancy, doubling approximately every two to three days during early gestation, which aids in confirming whether a woman is pregnant. This hormonal change is crucial for the maintenance of pregnancy during its initial stages, making it a definitive marker for diagnosis.

In contrast, while estrogen and progesterone levels do vary during pregnancy, the increase in hCG is the most definitive change associated with confirming pregnancy.