What Hormone is Tested for in Pregnancy Tests

What Hormone is Tested for in Pregnancy Tests

Pregnancy tests detect the presence of the hormone called Human Chorionic Gonadotropin (hCG), which is produced by the developing embryo shortly after conception.

Significance of pregnancy hormone

Once the blastocyst or fertilized egg implants itself in the uterus, the part that will grow to become the placenta starts producing hCG and its variants. This hormone prevents the shedding of the uterus’s blood-rich lining, thereby preventing the woman from undergoing her menstrual cycle. This blood will later be utilized in developing and nourishing the baby. As the levels of hCG increase, it becomes easily detectable in pregnancy tests.

It takes about six days after fertilization for hCG to be secreted for the first time. The level of this hormone rises within a few days of implantation and reaches its peak between the 60th and 90th day of pregnancy. When a pregnancy test detects the presence of hCG, the result is positive. Early pregnancy tests should also detect variants of this hormone; however, reliable results can only be obtained when the level of hCG has sufficiently increased.

Identification of Pregnancy hormone

  • A home pregnancy test can detect the presence of human chorionic gonadotropin (hCG) using a urine sample. However, when the test is conducted in a laboratory, hCG can be detected from either a blood or urine sample. Blood tests are more sensitive and can provide reliable results as soon as implantation begins.
  • Tests claiming early detection of pregnancy are capable of detecting variants of hCG, known as Human Chorionic Gonadotrophin-Hyperglycosylated (hCG-H).
  • In pregnant women, the level of human chorionic gonadotropin increases rapidly. During the first eight weeks of pregnancy, it doubles every other day. This rapid increase allows pregnancy tests conducted later in the pregnancy to detect the hormone more reliably compared to tests conducted immediately after implantation.
  • It’s important to note that even if you are pregnant, your test may show a negative result due to a low level of hCG. Tests are most accurate when conducted later after implantation, allowing for a higher concentration of the hormone to be detected.