The pregnancy test is based on detection of which hormone ?

Options

A. Progesterone
B. Estrogen
C. HCG
D. LH

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the hormone that is detected in pregnancy tests. This requires knowledge of hormones associated with pregnancy.

2. **Identifying Pregnancy Hormones**: During pregnancy, several hormones are produced. Notably, some are specific to pregnancy, while others are present in both pregnant and non-pregnant females.

3. **Key Hormones**: The key hormones associated with pregnancy include:
- **Human Chorionic Gonadotropin (HCG)**: This hormone is secreted by the placenta shortly after implantation of the embryo. It is the earliest hormone detectable in pregnancy tests.
- **Relaxin**: Secreted by the ovary during later stages of pregnancy, it helps relax uterine ligaments.
- **Human Placental Lactogen**: Also secreted by the placenta, it plays a role in metabolism during pregnancy.

4. **Focus on HCG**: Among these hormones, HCG is the most significant for pregnancy testing because it appears in the bloodstream and urine within about 15 days after fertilization.

5. **Conclusion**: The pregnancy test, such as the urine pregnancy test (UPT), detects the presence of HCG. Other hormones like progesterone and estrogen are present during pregnancy but are not specific indicators of pregnancy since they are also found in non-pregnant females.

6. **Final Answer**: The hormone detected in pregnancy tests is **Human Chorionic Gonadotropin (HCG)**.

---